Among different existing vibration isolation methods,open trenches is a technique that is commonly used for reducing the transfer of ground vibrations.Despite many benefits of such a technique for isolating ground vib...Among different existing vibration isolation methods,open trenches is a technique that is commonly used for reducing the transfer of ground vibrations.Despite many benefits of such a technique for isolating ground vibrations,its primary disadvantage is its instability and lack of vibration isolation effectiveness apart from the stability of the trenches.To address these concerns,a new technique has been developed by the authors,which includes filling up these trenches with a group of hollow pipes in a specific pattern.This is a novel method for reducing ground vibrations by burying hollow pipes horizontally.Through the use of three-dimensional(3D)finite-element modeling,the effectiveness of such hollow pipes in decreasing ground vibrations generated by harmonic stress excitation on the ground surface was investigated.Compared to open trench and rows of piles,these pipe assemblages have been shown to be very successful in reducing ground vibration transmission while also addressing issues of instability and enhancing vibration isolation efficiency.A 3D dynamic numerical model is constructed in PLAXIS3D,and the findings are validated against earlier publications.Next,a comparison research study is conducted,with its focus between horizontal hollow and vertical pipe piles.Finally,a detailed parametric study is carried out to establish the effect of each of the wave barrier’s architectural,material,and loading elements on its vibration isolation effectiveness.Critical parameters are discovered and tuned to maximize the efficiency of this new technique.展开更多
Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In...Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In this study,a machine learning(ML)-assisted weak vibration design method under harsh environmental excitations is proposed.The dynamic model of a typical pipe is developed using the absolute nodal coordinate formulation(ANCF)to determine its vibrational characteristics.With the harsh vibration environments as the preserved frequency band(PFB),the safety design is defined by comparing the natural frequency with the PFB.By analyzing the safety design of pipes with different constraint parameters,the dataset of the absolute safety length and the absolute resonance length of the pipe is obtained.This dataset is then utilized to develop genetic programming(GP)algorithm-based ML models capable of producing explicit mathematical expressions of the pipe's absolute safety length and absolute resonance length with the location,stiffness,and total number of retaining clips as design variables.The proposed ML models effectively bridge the dataset with the prediction results.Thus,the ML model is utilized to stagger the natural frequency,and the PFB is utilized to achieve the weak vibration design.The findings of the present study provide valuable insights into the practical application of weak vibration design.展开更多
It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A s...It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.展开更多
The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the dam...The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.展开更多
Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take...Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.展开更多
This work investigated the dynamic behavior of vertical pipes conveying gas-liquid two-phase flow when subjected to external excitations at both ends.Even with minimal excitation amplitude,resonance can occur when the...This work investigated the dynamic behavior of vertical pipes conveying gas-liquid two-phase flow when subjected to external excitations at both ends.Even with minimal excitation amplitude,resonance can occur when the excitation frequency aligns with the natural frequency of the pipe,significantly increasing the degree of operational risk.The governing equation of motion based on the Euler-Bernoulli beam is derived for the relative deflection with stationary simply supported ends,with the effects of the external excitations represented by source terms distributed along the pipe length.The fourth-order partial differential equation is solved via the generalized integral transform technique(GITT),with the solution successfully verified via comparison with results in the literature.A comprehensive analysis of the vibration phenomena and changes in the motion state of the pipe is conducted for three classes of external excitation conditions:same frequency and amplitude(SFSA),same frequency but different amplitudes(SFDA),and different frequencies and amplitudes(DFDA).The numerical results show that with increasing gas volume fraction,the position corresponding to the maximum vibration displacement shifts upward.Compared with conditions without external excitation,the vibration displacement of the pipe conveying two-phase flow under external excitation increases significantly.The frequency of external excitation has a significant effect on the dynamic behavior of a pipe conveying two-phase flow.展开更多
Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation...Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation of rectangular jacked pipes and the distribution of the earth pressure on jacked pipes,we present an analytical solution for predicting the vertical earth pressure on deep-buried rectangular pipe jacking tunnels,incorporating the tunnelling-induced ground loss distribution.Our proposed analytical model consists of the upper multi-layer parabolic soil arch and the lower friction arch.The key parameters(i.e.,width and height of friction arch B and height of parabolic soil arch H 1)are determined according to the existing research,and an analytical solution for K l is derived based on the distribution characteristics of the principal stress rotation angle.With consideration for the transition effect of the mechanical characteristics of the parabolic arch zone,an analytical solution for soil load transfer is derived.The prediction results of our analytical solution are compared with tests and simulation results to validate the effectiveness of the proposed analytical solution.Finally,the effects of different parameters on the soil pressure are discussed.展开更多
Mechanical properties are critical to the quality of hot-rolled steel pipe products.Accurately understanding the relationship between rolling parameters and mechanical properties is crucial for effective prediction an...Mechanical properties are critical to the quality of hot-rolled steel pipe products.Accurately understanding the relationship between rolling parameters and mechanical properties is crucial for effective prediction and control.To address this,an industrial big data platform was developed to collect and process multi-source heterogeneous data from the entire production process,providing a complete dataset for mechanical property prediction.The adaptive bandwidth kernel density estimation(ABKDE)method was proposed to adjust bandwidth dynamically based on data density.Combining long short-term memory neural networks with ABKDE offers robust prediction interval capabilities for mechanical properties.The proposed method was deployed in a large-scale steel plant,which demonstrated superior prediction interval performance compared to lower upper bound estimation,mean variance estimation,and extreme learning machine-adaptive bandwidth kernel density estimation,achieving a prediction interval normalized average width of 0.37,a prediction interval coverage probability of 0.94,and the lowest coverage width-based criterion of 1.35.Notably,shapley additive explanations-based explanations significantly improved the proposed model’s credibility by providing a clear analysis of feature impacts.展开更多
The development and supporting technologies of high-strain line pipe steel and pipes used for oil and gas pipeline projects in special geological environments(such as earthquake zone,landslide zone,mine goaf and subsi...The development and supporting technologies of high-strain line pipe steel and pipes used for oil and gas pipeline projects in special geological environments(such as earthquake zone,landslide zone,mine goaf and subsidence zone)is one of the international research hotspots,and it is also a major problem that China's major oil and gas pipeline projects have to solve.Focusing on a series of key technical difficulties in the research&development and application of high-strain line pipe steel and pipes,a number of theoretical and technological innovations have been achieved after more than ten years of joint researches.And the main achievements are as follows.First,the method of applying many different parameters(e.g.stress ratio,yield to tensile ratio and uniform elongation(UEL))to comprehensively characterize and evaluate the deformation behavior of steel pipes is proposed,and a technical index system and standard for the new products of X70HD/X80HD high-strain line pipe steel and pipes are established.Second,a complete set of X70HD/X80HD steel plate manufacturing technology is researched and developed,and the high-strain steel plate with the properties of low yield to tensile ratio,high uniform elongation,high stress ratio and high strength and toughness is worked out.Third,the X70HD/X80HD JCOE and UOE high-strain longitudinal submerged arc welded pipe manufacturing technology is researched and developed,reasonable performance matching between a steel pipe and a welding seam is realized,and the performance deterioration in the process of forming,welding,diameter-expending and thermal coating is solved.Fourth,a full-scale test device of steel pipe internal pressure t bending large deformation is independently developed,and the physical simulation based steel pipe deformation test technology is formed.X70HD/X80HD high-strain line pipe steel and pipes have been applied in the West to East Gas Pipeline,the ChinaeMyanmar Pipeline and other major gas pipeline projects in the large scale,and their application effects are remarkable.To satisfy the new needs of pipeline construction and long-term safe operation under complex geological conditions,some suggestions were put forwarded,such as developing new methods of strain-based pipeline design,and researching and developing or improving the supporting technologies suitable for the higher matching requirements of girth weld,such as welding methods,welding materials,welding processes,and girth weld performance quality and defect control requirements.展开更多
The influence of Ti and Zr,Nb alloying on the microstructures and performance of laser-welded molybdenum socket joints was investigated.Following Nb alloying,the average microhardness of the fusion zone(FZ)increased f...The influence of Ti and Zr,Nb alloying on the microstructures and performance of laser-welded molybdenum socket joints was investigated.Following Nb alloying,the average microhardness of the fusion zone(FZ)increased from HV 194.7 to HV 283.3.Additionally,Nb can react with O to form dispersed Nb_(2)O_(5) along grain boundaries,impeding grain boundary migration and dislocation movement while reducing the content of volatile Mo oxide along these boundaries.The incorporation of Nb in FZ partially inhibits pore defects and enhances joint load-bearing capacity.In comparison to the laser-welded joints without adding Nb(LW),the tensile strength of the laser-welded joints with Nb alloying(LW-Nb)was significantly improved by approximately 69%from 327.5 to 551.7 MPa.Furthermore,the fracture mechanism of the joints transitioned from intergranular fracture to transgranular fracture.展开更多
The diffusion of hydrogen-blended natural gas(HBNG)from buried pipelines in the event of a leak is typically influenced by soil properties,including porosity,particle size,temperature distribution,relative humidity,an...The diffusion of hydrogen-blended natural gas(HBNG)from buried pipelines in the event of a leak is typically influenced by soil properties,including porosity,particle size,temperature distribution,relative humidity,and the depth of the pipeline.This study models the soil as an isotropic porous medium and employs a CFD-based numerical framework to simulate gas propagation,accounting for the coupled effects of soil temperature and humidity.The model is rigorously validated against experimental data on natural gas diffusion in soil.It is then used to explore the impact of relevant parameters on the diffusion behavior of HBNG under conditions of low leakage flux.The results reveal distinct diffusion dynamics across different soil types:hydrogen(H_(2))diffuses most rapidly in clay,more slowly in sandy soil,and slowest in loam.At the ground surface directly above the leakage point,H_(2)concentrations rise rapidly initially before stabilizing,while at more distant surface locations,the increase is gradual,with delays that grow with distance.In particular,in a micro-leak scenario,characterized by a pipeline buried 0.8 m deep and a leakage velocity of 3.492 m/s,the time required for the H_(2)concentration to reach 1%at the surface,2 m horizontally from the leak source,is approximately 4.8 h for clay,5 h for sandy soil,and 7 h for loam.The time taken for gas to reach the surface is highly sensitive to the burial depth of the pipeline.After 18 h of diffusion,the surface H_(2)molar fraction directly above the leak reaches 3.75%,3.2%,and 2.75%for burial depths of 0.8,1.1,and 1.5 m,respectively,with the concentration inversely proportional to the depth.Soil temperature exerts minimal influence on the overall diffusion rate but slows the rise in H_(2)concentration directly above the leak as temperature increases.Meanwhile,the effect of soil humidity on H_(2)diffusion is negligible.展开更多
In concentric annular pipes,the difference in curvature between the inner and outer wall surfaces creates significant variations in the heat transfer characteristics of the two surfaces.The simplifications of the Ditt...In concentric annular pipes,the difference in curvature between the inner and outer wall surfaces creates significant variations in the heat transfer characteristics of the two surfaces.The simplifications of the Dittus-Boelter equation for circular pipes make it unsuitable for the complex flow induced by the geometry and heat transfer coupling effects in annular pipes.This prevents it from accurately predicting the turbulent heat transfer in concentric annular pipes.This paper used realizableκ–εand low Reynolds number models to conduct numerical simulations of turbulent convective heat transfer in concentric annular pipes and circular pipes.The results indicated that the local heat transfer coefficient and Nusselt number of the inner wall surface of the annular pipe were both higher than those of the outer wall surface.The Darcy resistance coefficient decreased upon increasing the Reynolds number and increased with the inner diameter-to-outer diameter ratio.When using the equivalent diameter as the characteristic scale,the turbulent heat transfer correlation obtained from circular pipes produced significant errors when used to approximate the turbulent convective heat transfer in concentric annular pipes.This error was greater for the inner wall surface,especially when the inner and outer diameters were relatively small,as the Nusselt number error on the inner wall surface reached 60.62%.The error of the Nusselt number on the outer wall surface reached 19.51%.展开更多
With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ...With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.展开更多
Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further system...Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further systematically investigates the influence of different debris slurry mass ratios(SLRs)and different particle size distributions(PSDs)on the pipe-rock friction characteristics using friction tests.The test results reveal that under the same PSD,an adequate amount of slurry(with an SLR of 1:4)consistently yields the lowest friction coefficient.When the SLR is between 1:2 and 1:3,the viscosity of the slurry reaches its peak,resulting in the highest friction coefficient.Additionally,when the PSD is 1:1:5 and 1:1:15,the friction coefficient is primarily governed by the plowing effect at the contact surface.When the PSD is 5:1:1 and 15:1:1,the friction coefficient is mainly controlled by the void ratio(VR)of debris.In the case of PSDs 1:5:1 and 1:15:1,the friction coefficient is jointly controlled by the adhesion effect of high-viscosity slurry and the plowing effect at the contact surface,and it gradually shifts towards being dominated by the VR as the amount of debris increases.Regardless of the SLRs and PSDs,the continuous deposition of debris and the injection of slurry incessantly exacerbate both the plowing and adhesion effects,creating a vicious cycle.This is the reason why the high-pressure water flushing method can not only fail to resolve the issue but also accelerate the occurrence of the surge in jacking force.展开更多
This study investigates the load-bearing capacity of open-ended pipe piles in sandy soil, with a specific focus on the impact of soil plug constraints at four levels(no plug, 25% plug, 50% plug, and full plug). Levera...This study investigates the load-bearing capacity of open-ended pipe piles in sandy soil, with a specific focus on the impact of soil plug constraints at four levels(no plug, 25% plug, 50% plug, and full plug). Leveraging a dataset comprising open-ended pipe piles with varying geometrical and geotechnical properties, this research employs shallow neural network(SNN) and deep neural network(DNN) models to predict plugging conditions for both driven and pressed installation types. This paper underscores the importance of key parameters such as the settlement value,applied load, installation type, and soil configuration(loose, medium, and dense) in accurately predicting pile settlement. These findings offer valuable insights for optimizing pile design and construction in geotechnical engineering,addressing a longstanding challenge in the field. The study demonstrates the potential of the SNN and DNN models in precisely identifying plugging conditions before pile driving, with the SNN achieving R2 values ranging from0.444 to 0.711 and RMSPE values ranging from 24.621% to 48.663%, whereas the DNN exhibits superior performance, with R2 values ranging from 0.815 to 0.942 and RMSPE values ranging from 4.419% to 10.325%. These results have significant implications for enhancing construction practices and reducing uncertainties associated with pile foundation projects in addition to leveraging artificial intelligence tools to avoid long experimental procedures.展开更多
Revealing the combined influence of interfacial damage and nonlinear factors on the forced vibration is significant for the stability design of fluid-conveying pipes, which are usually assembled in aircraft. The nonli...Revealing the combined influence of interfacial damage and nonlinear factors on the forced vibration is significant for the stability design of fluid-conveying pipes, which are usually assembled in aircraft. The nonlinear forced resonance of fluid-conveying layered pipes with a weak interface and a movable boundary under the external excitation is studied. The pipe is simply supported at both ends, with one end subject to a viscoelastic boundary constraint described by KelvinVoigt model. The weak interface in the pipe is considered in the refined displacement field of the layered pipe employing the interfacial cohesive law. The governing equations are derived by Hamilton's variational principle. Geometric nonlinearities including nonlinear curvature, longitudinal inertia nonlinearity and nonlinear constraint force are comprehensively considered during the theoretical derivation. Amplitude-frequency bifurcation diagrams are obtained utilizing a perturbation-Incremental Harmonic Balance Method(IHBM). Results show that interfacial damage and viscoelastic constraints from boundary and foundation have an important influence on the linear and nonlinear dynamic behavior of the system.展开更多
This study investigates the dynamical behavior of two parallel fluid-conveying pipes by developing a non-planar dynamical model of the two pipes coupled with an intermediate spring. A systematic analysis is conducted ...This study investigates the dynamical behavior of two parallel fluid-conveying pipes by developing a non-planar dynamical model of the two pipes coupled with an intermediate spring. A systematic analysis is conducted to evaluate the effects of spring parameters on the non-planar vibration characteristics and buckling behaviors of the coupled system. The nonlinear governing equations are derived with Hamilton's principle,subsequently discretized through Galerkin's method, and finally numerically solved by the Runge-Kutta algorithm. Based on the linearized equations, an eigenvalue analysis is performed to obtain the coupled frequencies, modal shapes, and critical flow velocities for buckling instability. Quantitative assessments further elucidate the effects of the spring position and stiffness coefficient on the coupled frequencies and critical flow velocities.Nonlinear dynamic analyses reveal the evolution of buckling patterns and bifurcation behaviors between the lateral displacements of the two pipes and the flow velocity. Numerical results indicate that the intermediate spring increases the susceptibility to buckling instability in the out-of-plane direction compared with the in-plane direction. Furthermore, synchronized lateral displacements emerge in both pipes when the flow velocity of one pipe exceeds the critical threshold. This work is expected to provide a theoretical foundation for the stability assessment and vibration analysis in coupled fluid-conveying pipe systems.展开更多
To improve the thermal performance and temperature uniformity of battery pack,this paper presents a novel battery thermal management system(BTMS)that integrates oscillating heat pipe(OHP)technology with liquid cooling...To improve the thermal performance and temperature uniformity of battery pack,this paper presents a novel battery thermal management system(BTMS)that integrates oscillating heat pipe(OHP)technology with liquid cooling.The primary innovation of the new hybrid BTMS lies in the use of an OHP with vertically arranged evaporator and condenser,enabling dual heat transfer pathways through liquid cooling plate and OHP.This study experimentally investigates the performance characteristics of the⊥-shaped OHP and hybrid BTMS.Results show that lower filling ratios significantly enhance the OHP’s startup performance but reduce operational stability,with optimal performance achieved at a 26.1%filling ratio.Acetone,as a single working fluid,exhibited superior heat transfer performance under low-load conditions compared to mixed fluids,while the acetone/ethanol mixture,forming a non-azeotropic solution,minimized temperature fluctuations.At 100 W,the⊥-shaped OHP with a horizontally arranged evaporator demonstrated better heat transfer performance than 2D-OHP designs.Compared to a liquid BTMS using water coolant at 280 W,the hybrid BTMS reduced the equivalent thermal resistance(RBTMS)and maximum temperature difference(ΔTmax)by 8.06%and 19.1%,respectively.When graphene nanofluid was used as the coolant in hybrid BTMS,the battery pack’s average temperature(Tb)dropped from 52.2℃ to 47.9℃,with RBTMS andΔTmax decreasing by 20.1%and 32.7%,respectively.These findings underscore the hybrid BTMS’s suitability for high heat load applications,offering a promising solution for electric vehicle thermal management.展开更多
The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governin...The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governing equations of motion for the pipe are derived using Hamilton’s principle.The finite element method,combined with the Galerkin approach,is employed to obtain the mass,damping,and stiffness matrices.To identify damage locations through pipe mode-shape decomposition,an index called the“matching pursuit residual”is introduced as a novel contribution of this study.The proposed method facilitates damage detection at various levels and locations under different boundary conditions.The findings demonstrate that the MP residual damage index can accurately localize damage in the pipes.Furthermore,the results of the numerical and experimental tests showcase the efficiency of the proposed method,highlighting that the MP signal approximation algorithm effectively detects damage in structures.展开更多
基金National Science Fund for Distinguished Young Scholars of China under Grant No.51725802NSFC&High-Speed Railway Joint Fund under Grant No.U1934208。
文摘Among different existing vibration isolation methods,open trenches is a technique that is commonly used for reducing the transfer of ground vibrations.Despite many benefits of such a technique for isolating ground vibrations,its primary disadvantage is its instability and lack of vibration isolation effectiveness apart from the stability of the trenches.To address these concerns,a new technique has been developed by the authors,which includes filling up these trenches with a group of hollow pipes in a specific pattern.This is a novel method for reducing ground vibrations by burying hollow pipes horizontally.Through the use of three-dimensional(3D)finite-element modeling,the effectiveness of such hollow pipes in decreasing ground vibrations generated by harmonic stress excitation on the ground surface was investigated.Compared to open trench and rows of piles,these pipe assemblages have been shown to be very successful in reducing ground vibration transmission while also addressing issues of instability and enhancing vibration isolation efficiency.A 3D dynamic numerical model is constructed in PLAXIS3D,and the findings are validated against earlier publications.Next,a comparison research study is conducted,with its focus between horizontal hollow and vertical pipe piles.Finally,a detailed parametric study is carried out to establish the effect of each of the wave barrier’s architectural,material,and loading elements on its vibration isolation effectiveness.Critical parameters are discovered and tuned to maximize the efficiency of this new technique.
基金Project supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.12421002)the National Science Funds for Distinguished Young Scholars of China(No.12025204)+1 种基金the National Natural Science Foundation of China(No.12372015)China Scholarship Council(No.202206890065)。
文摘Multi-constrained pipes conveying fluid,such as aircraft hydraulic control pipes,are susceptible to resonance fatigue in harsh vibration environments,which may lead to system failure and even catastrophic accidents.In this study,a machine learning(ML)-assisted weak vibration design method under harsh environmental excitations is proposed.The dynamic model of a typical pipe is developed using the absolute nodal coordinate formulation(ANCF)to determine its vibrational characteristics.With the harsh vibration environments as the preserved frequency band(PFB),the safety design is defined by comparing the natural frequency with the PFB.By analyzing the safety design of pipes with different constraint parameters,the dataset of the absolute safety length and the absolute resonance length of the pipe is obtained.This dataset is then utilized to develop genetic programming(GP)algorithm-based ML models capable of producing explicit mathematical expressions of the pipe's absolute safety length and absolute resonance length with the location,stiffness,and total number of retaining clips as design variables.The proposed ML models effectively bridge the dataset with the prediction results.Thus,the ML model is utilized to stagger the natural frequency,and the PFB is utilized to achieve the weak vibration design.The findings of the present study provide valuable insights into the practical application of weak vibration design.
文摘It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.
基金Project supported by the National Natural Science Foundation of China (No. 12272323)。
文摘The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.
基金supported by the National Natural Science Foundation of China(Grant Nos.52168046 and 52178321)the Natural Science Foundation of Guangxi Province,China(Grant No.2021AC18019).
文摘Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.
基金financially supported by the Key Research and Development Program of Shandong Province(Grant Nos.2022CXGC020405,2023CXGC010415 and 2025TSGCCZZB0238)the National Natural Science Foundation of China(Grant No.52171288)the financial support from CNPq,FAPERJ,ANP,Embrapii,and China National Petroleum Corporation(CNPC).
文摘This work investigated the dynamic behavior of vertical pipes conveying gas-liquid two-phase flow when subjected to external excitations at both ends.Even with minimal excitation amplitude,resonance can occur when the excitation frequency aligns with the natural frequency of the pipe,significantly increasing the degree of operational risk.The governing equation of motion based on the Euler-Bernoulli beam is derived for the relative deflection with stationary simply supported ends,with the effects of the external excitations represented by source terms distributed along the pipe length.The fourth-order partial differential equation is solved via the generalized integral transform technique(GITT),with the solution successfully verified via comparison with results in the literature.A comprehensive analysis of the vibration phenomena and changes in the motion state of the pipe is conducted for three classes of external excitation conditions:same frequency and amplitude(SFSA),same frequency but different amplitudes(SFDA),and different frequencies and amplitudes(DFDA).The numerical results show that with increasing gas volume fraction,the position corresponding to the maximum vibration displacement shifts upward.Compared with conditions without external excitation,the vibration displacement of the pipe conveying two-phase flow under external excitation increases significantly.The frequency of external excitation has a significant effect on the dynamic behavior of a pipe conveying two-phase flow.
基金Project(2022YJS073)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2024YFE0198500)supported by the National Key Research and Development Program of China:Intergovernmental International Science and Technology Innovation CooperationProject(U2469207)supported by the National Natural Science Foundation Railway Innovation and Development Joint Fund Project,China。
文摘Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation of rectangular jacked pipes and the distribution of the earth pressure on jacked pipes,we present an analytical solution for predicting the vertical earth pressure on deep-buried rectangular pipe jacking tunnels,incorporating the tunnelling-induced ground loss distribution.Our proposed analytical model consists of the upper multi-layer parabolic soil arch and the lower friction arch.The key parameters(i.e.,width and height of friction arch B and height of parabolic soil arch H 1)are determined according to the existing research,and an analytical solution for K l is derived based on the distribution characteristics of the principal stress rotation angle.With consideration for the transition effect of the mechanical characteristics of the parabolic arch zone,an analytical solution for soil load transfer is derived.The prediction results of our analytical solution are compared with tests and simulation results to validate the effectiveness of the proposed analytical solution.Finally,the effects of different parameters on the soil pressure are discussed.
基金supported by the National Key Research and Development Plan(Grant No.2023YFB3712400)the National Key Research and Development Plan(Grant No.2020YFB1713600).
文摘Mechanical properties are critical to the quality of hot-rolled steel pipe products.Accurately understanding the relationship between rolling parameters and mechanical properties is crucial for effective prediction and control.To address this,an industrial big data platform was developed to collect and process multi-source heterogeneous data from the entire production process,providing a complete dataset for mechanical property prediction.The adaptive bandwidth kernel density estimation(ABKDE)method was proposed to adjust bandwidth dynamically based on data density.Combining long short-term memory neural networks with ABKDE offers robust prediction interval capabilities for mechanical properties.The proposed method was deployed in a large-scale steel plant,which demonstrated superior prediction interval performance compared to lower upper bound estimation,mean variance estimation,and extreme learning machine-adaptive bandwidth kernel density estimation,achieving a prediction interval normalized average width of 0.37,a prediction interval coverage probability of 0.94,and the lowest coverage width-based criterion of 1.35.Notably,shapley additive explanations-based explanations significantly improved the proposed model’s credibility by providing a clear analysis of feature impacts.
基金Project supported by the National Key R&D Program of China“Research and Development of High-strain Marine Line Pipes”(No.2018YFC03010300)PetroChina's Major Science&Technology Project“Research on Key Technologies for Controlling Pipe Fracture and Deformation in the Second West-East Gas Pipeline”(No.2009E-0105)+1 种基金“Research and Development of Special Welded Pipes for the Second West-East Gas Pipeline”(No.2009E-0104)CNPC's Science&Technology Infrastructure Program“CNPC Infrastructure Construction of Key Laboratory for Petroleum Tubular Engineering”(No.07H611).
文摘The development and supporting technologies of high-strain line pipe steel and pipes used for oil and gas pipeline projects in special geological environments(such as earthquake zone,landslide zone,mine goaf and subsidence zone)is one of the international research hotspots,and it is also a major problem that China's major oil and gas pipeline projects have to solve.Focusing on a series of key technical difficulties in the research&development and application of high-strain line pipe steel and pipes,a number of theoretical and technological innovations have been achieved after more than ten years of joint researches.And the main achievements are as follows.First,the method of applying many different parameters(e.g.stress ratio,yield to tensile ratio and uniform elongation(UEL))to comprehensively characterize and evaluate the deformation behavior of steel pipes is proposed,and a technical index system and standard for the new products of X70HD/X80HD high-strain line pipe steel and pipes are established.Second,a complete set of X70HD/X80HD steel plate manufacturing technology is researched and developed,and the high-strain steel plate with the properties of low yield to tensile ratio,high uniform elongation,high stress ratio and high strength and toughness is worked out.Third,the X70HD/X80HD JCOE and UOE high-strain longitudinal submerged arc welded pipe manufacturing technology is researched and developed,reasonable performance matching between a steel pipe and a welding seam is realized,and the performance deterioration in the process of forming,welding,diameter-expending and thermal coating is solved.Fourth,a full-scale test device of steel pipe internal pressure t bending large deformation is independently developed,and the physical simulation based steel pipe deformation test technology is formed.X70HD/X80HD high-strain line pipe steel and pipes have been applied in the West to East Gas Pipeline,the ChinaeMyanmar Pipeline and other major gas pipeline projects in the large scale,and their application effects are remarkable.To satisfy the new needs of pipeline construction and long-term safe operation under complex geological conditions,some suggestions were put forwarded,such as developing new methods of strain-based pipeline design,and researching and developing or improving the supporting technologies suitable for the higher matching requirements of girth weld,such as welding methods,welding materials,welding processes,and girth weld performance quality and defect control requirements.
基金National Key Research and Development Project of China (No. 2022YFB3707602)National Natural Science Foundation of China (Nos. 52005393, 51775416)。
文摘The influence of Ti and Zr,Nb alloying on the microstructures and performance of laser-welded molybdenum socket joints was investigated.Following Nb alloying,the average microhardness of the fusion zone(FZ)increased from HV 194.7 to HV 283.3.Additionally,Nb can react with O to form dispersed Nb_(2)O_(5) along grain boundaries,impeding grain boundary migration and dislocation movement while reducing the content of volatile Mo oxide along these boundaries.The incorporation of Nb in FZ partially inhibits pore defects and enhances joint load-bearing capacity.In comparison to the laser-welded joints without adding Nb(LW),the tensile strength of the laser-welded joints with Nb alloying(LW-Nb)was significantly improved by approximately 69%from 327.5 to 551.7 MPa.Furthermore,the fracture mechanism of the joints transitioned from intergranular fracture to transgranular fracture.
基金supported by the National Key Research and Development Program of China(No.2022YFB4002900).
文摘The diffusion of hydrogen-blended natural gas(HBNG)from buried pipelines in the event of a leak is typically influenced by soil properties,including porosity,particle size,temperature distribution,relative humidity,and the depth of the pipeline.This study models the soil as an isotropic porous medium and employs a CFD-based numerical framework to simulate gas propagation,accounting for the coupled effects of soil temperature and humidity.The model is rigorously validated against experimental data on natural gas diffusion in soil.It is then used to explore the impact of relevant parameters on the diffusion behavior of HBNG under conditions of low leakage flux.The results reveal distinct diffusion dynamics across different soil types:hydrogen(H_(2))diffuses most rapidly in clay,more slowly in sandy soil,and slowest in loam.At the ground surface directly above the leakage point,H_(2)concentrations rise rapidly initially before stabilizing,while at more distant surface locations,the increase is gradual,with delays that grow with distance.In particular,in a micro-leak scenario,characterized by a pipeline buried 0.8 m deep and a leakage velocity of 3.492 m/s,the time required for the H_(2)concentration to reach 1%at the surface,2 m horizontally from the leak source,is approximately 4.8 h for clay,5 h for sandy soil,and 7 h for loam.The time taken for gas to reach the surface is highly sensitive to the burial depth of the pipeline.After 18 h of diffusion,the surface H_(2)molar fraction directly above the leak reaches 3.75%,3.2%,and 2.75%for burial depths of 0.8,1.1,and 1.5 m,respectively,with the concentration inversely proportional to the depth.Soil temperature exerts minimal influence on the overall diffusion rate but slows the rise in H_(2)concentration directly above the leak as temperature increases.Meanwhile,the effect of soil humidity on H_(2)diffusion is negligible.
基金Supported by the Major Program of the National Natural Science Foundation of China(Grant No.51736007).
文摘In concentric annular pipes,the difference in curvature between the inner and outer wall surfaces creates significant variations in the heat transfer characteristics of the two surfaces.The simplifications of the Dittus-Boelter equation for circular pipes make it unsuitable for the complex flow induced by the geometry and heat transfer coupling effects in annular pipes.This prevents it from accurately predicting the turbulent heat transfer in concentric annular pipes.This paper used realizableκ–εand low Reynolds number models to conduct numerical simulations of turbulent convective heat transfer in concentric annular pipes and circular pipes.The results indicated that the local heat transfer coefficient and Nusselt number of the inner wall surface of the annular pipe were both higher than those of the outer wall surface.The Darcy resistance coefficient decreased upon increasing the Reynolds number and increased with the inner diameter-to-outer diameter ratio.When using the equivalent diameter as the characteristic scale,the turbulent heat transfer correlation obtained from circular pipes produced significant errors when used to approximate the turbulent convective heat transfer in concentric annular pipes.This error was greater for the inner wall surface,especially when the inner and outer diameters were relatively small,as the Nusselt number error on the inner wall surface reached 60.62%.The error of the Nusselt number on the outer wall surface reached 19.51%.
文摘With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.
基金the funding support from the National Natural Science Foundations for Young Scientists of China(Grant No.52208391)Doctoral Foundation Project of Guizhou University(Grant No.2021e78).
文摘Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further systematically investigates the influence of different debris slurry mass ratios(SLRs)and different particle size distributions(PSDs)on the pipe-rock friction characteristics using friction tests.The test results reveal that under the same PSD,an adequate amount of slurry(with an SLR of 1:4)consistently yields the lowest friction coefficient.When the SLR is between 1:2 and 1:3,the viscosity of the slurry reaches its peak,resulting in the highest friction coefficient.Additionally,when the PSD is 1:1:5 and 1:1:15,the friction coefficient is primarily governed by the plowing effect at the contact surface.When the PSD is 5:1:1 and 15:1:1,the friction coefficient is mainly controlled by the void ratio(VR)of debris.In the case of PSDs 1:5:1 and 1:15:1,the friction coefficient is jointly controlled by the adhesion effect of high-viscosity slurry and the plowing effect at the contact surface,and it gradually shifts towards being dominated by the VR as the amount of debris increases.Regardless of the SLRs and PSDs,the continuous deposition of debris and the injection of slurry incessantly exacerbate both the plowing and adhesion effects,creating a vicious cycle.This is the reason why the high-pressure water flushing method can not only fail to resolve the issue but also accelerate the occurrence of the surge in jacking force.
文摘This study investigates the load-bearing capacity of open-ended pipe piles in sandy soil, with a specific focus on the impact of soil plug constraints at four levels(no plug, 25% plug, 50% plug, and full plug). Leveraging a dataset comprising open-ended pipe piles with varying geometrical and geotechnical properties, this research employs shallow neural network(SNN) and deep neural network(DNN) models to predict plugging conditions for both driven and pressed installation types. This paper underscores the importance of key parameters such as the settlement value,applied load, installation type, and soil configuration(loose, medium, and dense) in accurately predicting pile settlement. These findings offer valuable insights for optimizing pile design and construction in geotechnical engineering,addressing a longstanding challenge in the field. The study demonstrates the potential of the SNN and DNN models in precisely identifying plugging conditions before pile driving, with the SNN achieving R2 values ranging from0.444 to 0.711 and RMSPE values ranging from 24.621% to 48.663%, whereas the DNN exhibits superior performance, with R2 values ranging from 0.815 to 0.942 and RMSPE values ranging from 4.419% to 10.325%. These results have significant implications for enhancing construction practices and reducing uncertainties associated with pile foundation projects in addition to leveraging artificial intelligence tools to avoid long experimental procedures.
文摘Revealing the combined influence of interfacial damage and nonlinear factors on the forced vibration is significant for the stability design of fluid-conveying pipes, which are usually assembled in aircraft. The nonlinear forced resonance of fluid-conveying layered pipes with a weak interface and a movable boundary under the external excitation is studied. The pipe is simply supported at both ends, with one end subject to a viscoelastic boundary constraint described by KelvinVoigt model. The weak interface in the pipe is considered in the refined displacement field of the layered pipe employing the interfacial cohesive law. The governing equations are derived by Hamilton's variational principle. Geometric nonlinearities including nonlinear curvature, longitudinal inertia nonlinearity and nonlinear constraint force are comprehensively considered during the theoretical derivation. Amplitude-frequency bifurcation diagrams are obtained utilizing a perturbation-Incremental Harmonic Balance Method(IHBM). Results show that interfacial damage and viscoelastic constraints from boundary and foundation have an important influence on the linear and nonlinear dynamic behavior of the system.
基金supported by the National Natural Science Foundation of China(Nos.12325201,12272140,and 12322201)。
文摘This study investigates the dynamical behavior of two parallel fluid-conveying pipes by developing a non-planar dynamical model of the two pipes coupled with an intermediate spring. A systematic analysis is conducted to evaluate the effects of spring parameters on the non-planar vibration characteristics and buckling behaviors of the coupled system. The nonlinear governing equations are derived with Hamilton's principle,subsequently discretized through Galerkin's method, and finally numerically solved by the Runge-Kutta algorithm. Based on the linearized equations, an eigenvalue analysis is performed to obtain the coupled frequencies, modal shapes, and critical flow velocities for buckling instability. Quantitative assessments further elucidate the effects of the spring position and stiffness coefficient on the coupled frequencies and critical flow velocities.Nonlinear dynamic analyses reveal the evolution of buckling patterns and bifurcation behaviors between the lateral displacements of the two pipes and the flow velocity. Numerical results indicate that the intermediate spring increases the susceptibility to buckling instability in the out-of-plane direction compared with the in-plane direction. Furthermore, synchronized lateral displacements emerge in both pipes when the flow velocity of one pipe exceeds the critical threshold. This work is expected to provide a theoretical foundation for the stability assessment and vibration analysis in coupled fluid-conveying pipe systems.
基金funded by the Science and Technology Research Project of Jiangxi Provincial Department of Education(GJJ2404911)the Ministry of Higher Education,Malaysia through the Fundamental Research Grant Scheme:FRGS/1/2024/TK10/UMP/02/15 and Universiti Malaysia Pahang Al-Sultan Abdullah(RDU240117).
文摘To improve the thermal performance and temperature uniformity of battery pack,this paper presents a novel battery thermal management system(BTMS)that integrates oscillating heat pipe(OHP)technology with liquid cooling.The primary innovation of the new hybrid BTMS lies in the use of an OHP with vertically arranged evaporator and condenser,enabling dual heat transfer pathways through liquid cooling plate and OHP.This study experimentally investigates the performance characteristics of the⊥-shaped OHP and hybrid BTMS.Results show that lower filling ratios significantly enhance the OHP’s startup performance but reduce operational stability,with optimal performance achieved at a 26.1%filling ratio.Acetone,as a single working fluid,exhibited superior heat transfer performance under low-load conditions compared to mixed fluids,while the acetone/ethanol mixture,forming a non-azeotropic solution,minimized temperature fluctuations.At 100 W,the⊥-shaped OHP with a horizontally arranged evaporator demonstrated better heat transfer performance than 2D-OHP designs.Compared to a liquid BTMS using water coolant at 280 W,the hybrid BTMS reduced the equivalent thermal resistance(RBTMS)and maximum temperature difference(ΔTmax)by 8.06%and 19.1%,respectively.When graphene nanofluid was used as the coolant in hybrid BTMS,the battery pack’s average temperature(Tb)dropped from 52.2℃ to 47.9℃,with RBTMS andΔTmax decreasing by 20.1%and 32.7%,respectively.These findings underscore the hybrid BTMS’s suitability for high heat load applications,offering a promising solution for electric vehicle thermal management.
文摘The current study examines damage detection in fluid-conveying pipes supported on a Pasternak foundation.This study proposes a novel method that uses the matching pursuit(MP)algorithm for damage detection.The governing equations of motion for the pipe are derived using Hamilton’s principle.The finite element method,combined with the Galerkin approach,is employed to obtain the mass,damping,and stiffness matrices.To identify damage locations through pipe mode-shape decomposition,an index called the“matching pursuit residual”is introduced as a novel contribution of this study.The proposed method facilitates damage detection at various levels and locations under different boundary conditions.The findings demonstrate that the MP residual damage index can accurately localize damage in the pipes.Furthermore,the results of the numerical and experimental tests showcase the efficiency of the proposed method,highlighting that the MP signal approximation algorithm effectively detects damage in structures.
