The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from...The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.展开更多
Acoustic waves in the pseudo-triaxial experiment system experience refraction phenomena.The conventional assumption that acoustic waves propagate along a straight line in traditional methods can lead to significant er...Acoustic waves in the pseudo-triaxial experiment system experience refraction phenomena.The conventional assumption that acoustic waves propagate along a straight line in traditional methods can lead to significant errors in localization results.To the end,this paper presents a method for locating acoustic emission(AE)sources in pseudo-triaxial experiments using shortest paths and orthogonal constraints.The approach consists of three main steps:(1)establishing control equations for refraction paths from AE sources to sensor locations;(2)calculating refraction point locations using the shortest travel principle and orthogonal constraints;(3)determining source coordinates using Taylor's first-order expansion.The results from laboratory AE experiments demonstrate that the average localization accuracy of the new method is only 6.5 mm,which is 66%more precise than the accuracy(19.4 mm)of the traditional method.Furthermore,simulation results indicate that the new method is not affected by the refraction ratio of the media and maintains the highest positioning accuracy across various arrival and velocity errors.展开更多
Triaxial tests,a staple in rock engineering,are labor-intensive,sample-demanding,and costly,making their optimization highly advantageous.These tests are essential for characterizing rock strength,and by adopting a fa...Triaxial tests,a staple in rock engineering,are labor-intensive,sample-demanding,and costly,making their optimization highly advantageous.These tests are essential for characterizing rock strength,and by adopting a failure criterion,they allow for the derivation of criterion parameters through regression,facilitating their integration into modeling programs.In this study,we introduce the application of an underutilized statistical technique—orthogonal regression—well-suited for analyzing triaxial test data.Additionally,we present an innovation in this technique by minimizing the Euclidean distance while incorporating orthogonality between vectors as a constraint,for the case of orthogonal linear regression.Also,we consider the Modified Least Squares method.We exemplify this approach by developing the necessary equations to apply the Mohr-Coulomb,Murrell,Hoek-Brown,andÚcar criteria,and implement these equations in both spreadsheet calculations and R scripts.Finally,we demonstrate the technique's application using five datasets of varied lithologies from specialized literature,showcasing its versatility and effectiveness.展开更多
To investigate the impact of guide vane geometry—specifically,outlet angle,blade count,and radial height—on the performance of a Pump as Turbine(PAT),radial guide vanes were introduced upstream of the impeller in an...To investigate the impact of guide vane geometry—specifically,outlet angle,blade count,and radial height—on the performance of a Pump as Turbine(PAT),radial guide vanes were introduced upstream of the impeller in an IS80-50-315 low-specific-speed centrifugal PAT.Using an orthogonal test design,numerical simulations were conducted on 16 different PAT configurations,and the influence of vane geometry on performance was analyzed through a range analysis to determine the optimal parameter combinations.The results indicate that the number of guide vane blades significantly affects both the hydraulic efficiency and water head of the PAT under optimal operating conditions.Notably,the hydraulic efficiency of Configuration No.1(featuring five guide vane blades,a 6°outlet angle,and a 46 mm radial height)is 4.31%higher than that of Configuration No.13(with the same blade count but a 9°outlet angle and a 52 mm radial height).Additionally,Configuration No.1 exhibits lower turbulence kinetic energy dissipation and reduced blade loading.Furthermore,the study reveals that a smaller guide vane outlet angle and reduced radial height contribute to improved operational stability.展开更多
To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level ...To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.展开更多
Space-filling designs with superior low-dimensional properties are highly required in computer experiments.Strong orthogonal arrays(SOAs)represent a class of such designs that outperform ordinary orthogonal arrays in ...Space-filling designs with superior low-dimensional properties are highly required in computer experiments.Strong orthogonal arrays(SOAs)represent a class of such designs that outperform ordinary orthogonal arrays in their stratification properties within low dimensions.Nevertheless,current methods for constructing high-strength SOAs are rare,and they typically rely on regular designs,thereby limiting the number of runs in the final arrays to prime powers.This study presents new construction methods for three types of SOAs:SOAs of strength three,column-orthogonal SOAs(OSOAs)of strength three and three minus.The resulting designs have run sizes of twice an odd prime power without replications,filling the gaps in run sizes left by existing constructions.The projection properties of Addelman–Kempthorne orthogonal arrays are instrumental in the development of these construction methods.展开更多
This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lacti...This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lactic acid)/thermoplastic polyurethane(PLA/TPU)matrix.Specifically,using a 70 wt%/30 wt%PLA/TPU matrix and an L_(9)(3^(2))orthogonal design,composites were evaluated via morphology,shape memory,mechanical tests,and multi-criteria analysis.Moderate DCP enhanced crosslinking,improving storage modulus and thermal stability,while excessive DCP caused brittleness.Furthermore,MAH-g-PE effectively improved interfacial compatibility,and its synergy with DCP was dosage-dependent.Consequently,Sample 5 achieved optimal performance,exhibiting uniform fracture morphology,a shape fixation rate of98.8%with the fastest recovery,and balanced strength-ductility.Multi-criteria analysis identified elongation at break and recovery time as the top contributing factors,with consistent rankings validated by Spearman analysis(ρ=0.833,p<0.01).In summary,adjusting DCP and MAH-g-PE contents effectively modulates the crosslinking structure and interfacial properties of PLA/TPU composites,providing a viable strategy for developing high-performance,tunable 4D printing materials.展开更多
[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves ...[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves by CTAB method as the template,PCR system was optimized by L16(45)orthogonal design.[Result] Clear bands were amplified from 16 different combinations,but the amplification effects and yields had difference.The most economic and applicable system was as follows:20 ng DNA template,150 μmol/L dNT...展开更多
Influence of multiple structural parameters on the performance of a gun launch system driven by highpressure reactive gases is important for structural design and performance adjustment.A coupled lumped parameter mode...Influence of multiple structural parameters on the performance of a gun launch system driven by highpressure reactive gases is important for structural design and performance adjustment.A coupled lumped parameter model was utilized to predict the propellant combustion,and a dynamic finite element method was applied to approximate the mechanical interactions between the projectile and the barrel.The combustion and the mechanical interactions were coupled through a user subroutine interface in ABAQUS.The correctness and the capability of the finite element approximations in capturing small structural changes were validated by comparing predicted resistance with experiments.Based on the coupled model,the influence of structural parameters of a medium-caliber gun on the system performance was investigated.In order to reduce the research costs,orthogonal tests were designed to investigate the comprehensive effects of the parameters.According to statistical analysis,the important order of the structural parameters on the launching process was obtained.The results indicate that the influence of the width of the rotating band stands out among the studied parameters in the gun.The work provides a method to investigate the influence of multiple parameters on system performance and gives guidance for controlling the system performance.展开更多
Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructu...Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9（3）4], including the ratio of buffer solution （Na2B4O7· 10H2O） to raw material, concentration of Fructus Gardeniae in extracting solution, extraction time and pH of buffer solution. An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample. Results The maximum extraction yield of the crude extract was 5.0533 （mg/g） after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4%, the concentration of Fructus Gardeniae in the extraction solution was 1/12 （g/mL）, and pH of buffer solution was 4.5. The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid, and FTIR measurements also identified the presence of flavonoid in the extracts. Conclusion This work is expected to provide a basis for further research, development, and utilization of Fructus gardenia in flavonid extraction.展开更多
To provide theoretical basis and practical guidance for preparing composite rods by direct continuous casting, copper-clad aluminum composite rods of external copper layer diameter 12 mm and inner aluminum core diamet...To provide theoretical basis and practical guidance for preparing composite rods by direct continuous casting, copper-clad aluminum composite rods of external copper layer diameter 12 mm and inner aluminum core diameter 8 mm were manufactured. Orthogonal tests consisted of three factors and three levels were carried out to research the effects of melting copper temperature, continuous casting speed and nitrogen pressure on the performance of composite rods. Results showed that nitrogen pressure is the most important factor in influencing the surface quality; continuous casting speed is the most important factor in influencing copper & aluminum inter diffusion amount. Nitrogen pressure can noticeably improve the surface quality and make the rods easily be drawn out, but the surface quality does not show visible improvement when the nitrogen pressure is above 0.05 MPa. Measured by tests, the compound layer can be divided into three types according to its cladding layer degree: deficient cladding, normal cladding and excess cladding. The diameter of normal copper-clad aluminum composite rods can be successfully drawn less than 0.6 mm without annealing.展开更多
A prototype centrifugal pump with a specific speed of 110 is used to investigate and optimize the performances of a turbine for power generation.Particular attention is given to the design of the internal impeller.The...A prototype centrifugal pump with a specific speed of 110 is used to investigate and optimize the performances of a turbine for power generation.Particular attention is given to the design of the internal impeller.The internal flow field is simulated in the framework of a commercial computational fluid dynamics software(ANSYS).Four geometrical parameters of the impeller are considered,i.e.,the inlet diameter,the inlet width,the blade number,and the blade angle.The optimization is carried out on the basis of a three-level approach relying on an orthogonal test method.The results of the numerical simulations show good agreement with the experimental tests under different flow conditions.In accordance with the L9(34)design table,the head and efficiency under the rated flow rate of the nine designed schemes are calculated and processed with the method of range analysis to obtain an optimized model.展开更多
This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test ...This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors： traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters＇ effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.展开更多
The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanica...The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanical tests.The orthogonal experimental design was used to study the influence of plasma-MIG welding parameters on the aluminum weld porosity.The mixed orthogonal matrix L16(4 4×2 3) and analysis of variance (ANOVA)technique were employed to optimize the welding parameters.The experimental results indicate that the effect of plasma gas flow rate is dominant,the secondary factors are MIG welding voltage,welding speed,wire feed rate and plasma current in turn.Confirmation experiments were conducted under optimum conditions and there was almost no porosity in the welded joints,thus good mechanical performance joints were obtained.展开更多
The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized funct...The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.展开更多
The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-veloci...The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-velocity MSSICG,we propose an optimization design scheme combining orthogonal experimental design(OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors(radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium-and high-velocity MSSICG.展开更多
The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing paramet...The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.展开更多
The concave die design of self-pierce riveting(SPR) is of critical importance for product quality. The optimization of concave die parameters based on orthogonal test is proposed to explore the relationship between se...The concave die design of self-pierce riveting(SPR) is of critical importance for product quality. The optimization of concave die parameters based on orthogonal test is proposed to explore the relationship between self-pierce riveted joint quality and die parameters. There are nine independent die parameter factors in orthogonal test and each factor has 4 levels. In order to evaluate the interlock and neck thickness, we carry out numerical simulations by the software DEFORM-2D. Then, the primary and secondary factors that affect the joint quality have been found out by means of range analysis. Finally, an optimization scheme is brought forward to design concave die in SPR process, which indicates that the joint has higher quality than that of former orthogonal tests.This work can be extended by a detailed mechanical and fatigue analysis for the joint quality of SPR process.展开更多
[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the op...[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.展开更多
As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be ...As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be carried out before launching SCMs.This study developed a testing device and an SCM test by investigating SCMs and their underwater.The testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test unit.First,the basic indices of the testing device were determined from the performance and working parameters of the SCM.Second,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was designed.Finally,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test requirements.The measurement mainly involved equipment inspection before testing and an experimental test for the SCM.The validity and feasibility of the testing device and method were simultaneously verified through an association test.展开更多
基金supported by the National Natural Science Foundation of China(No.52388102)the Sichuan Science and Technology Program(No.2024NSFTD0011)the Fundamental Research Funds for the State Key Laboratory of Rail Transit Vehicle System of Southwest Jiaotong University(No.2023TPL-T11).
文摘The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.
基金the financial support provided by the National Key Research and Development Program for Young Scientists(Grant No.2021YFC2900400)the National Natural Science Foundation of China(Grant No.52304123)the China Postdoctoral Science Foundation(Grant No.2023M730412).
文摘Acoustic waves in the pseudo-triaxial experiment system experience refraction phenomena.The conventional assumption that acoustic waves propagate along a straight line in traditional methods can lead to significant errors in localization results.To the end,this paper presents a method for locating acoustic emission(AE)sources in pseudo-triaxial experiments using shortest paths and orthogonal constraints.The approach consists of three main steps:(1)establishing control equations for refraction paths from AE sources to sensor locations;(2)calculating refraction point locations using the shortest travel principle and orthogonal constraints;(3)determining source coordinates using Taylor's first-order expansion.The results from laboratory AE experiments demonstrate that the average localization accuracy of the new method is only 6.5 mm,which is 66%more precise than the accuracy(19.4 mm)of the traditional method.Furthermore,simulation results indicate that the new method is not affected by the refraction ratio of the media and maintains the highest positioning accuracy across various arrival and velocity errors.
文摘Triaxial tests,a staple in rock engineering,are labor-intensive,sample-demanding,and costly,making their optimization highly advantageous.These tests are essential for characterizing rock strength,and by adopting a failure criterion,they allow for the derivation of criterion parameters through regression,facilitating their integration into modeling programs.In this study,we introduce the application of an underutilized statistical technique—orthogonal regression—well-suited for analyzing triaxial test data.Additionally,we present an innovation in this technique by minimizing the Euclidean distance while incorporating orthogonality between vectors as a constraint,for the case of orthogonal linear regression.Also,we consider the Modified Least Squares method.We exemplify this approach by developing the necessary equations to apply the Mohr-Coulomb,Murrell,Hoek-Brown,andÚcar criteria,and implement these equations in both spreadsheet calculations and R scripts.Finally,we demonstrate the technique's application using five datasets of varied lithologies from specialized literature,showcasing its versatility and effectiveness.
基金support of the Innovation Fund for College Teachers of Department Education of Gansu(No.2024A-021)Colleges and Universities Industrial Support Program Projects of Gansu Province(Grant No.2020C-20)+1 种基金Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University(Grant Nos.szjj2019-016,LTDL2020-007)Key Research and Development Program of Gansu Province-Industrial Project(No.25YFGA021).
文摘To investigate the impact of guide vane geometry—specifically,outlet angle,blade count,and radial height—on the performance of a Pump as Turbine(PAT),radial guide vanes were introduced upstream of the impeller in an IS80-50-315 low-specific-speed centrifugal PAT.Using an orthogonal test design,numerical simulations were conducted on 16 different PAT configurations,and the influence of vane geometry on performance was analyzed through a range analysis to determine the optimal parameter combinations.The results indicate that the number of guide vane blades significantly affects both the hydraulic efficiency and water head of the PAT under optimal operating conditions.Notably,the hydraulic efficiency of Configuration No.1(featuring five guide vane blades,a 6°outlet angle,and a 46 mm radial height)is 4.31%higher than that of Configuration No.13(with the same blade count but a 9°outlet angle and a 52 mm radial height).Additionally,Configuration No.1 exhibits lower turbulence kinetic energy dissipation and reduced blade loading.Furthermore,the study reveals that a smaller guide vane outlet angle and reduced radial height contribute to improved operational stability.
基金Key Program of National Natural Science Foundation of China(52431001)。
文摘To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.
基金supported by the Fundamental Research Funds for the Central Universities[grant number 2025JBZX013]the National Natural Science Foundation of China[grant numbers 12001036,12271166,32030063]+1 种基金Young Elite Scientists Sponsorship Program by CAST[grant number 2022QNRC001]National Key Research and Development Program of China[grant number 2024YFA1016200].
文摘Space-filling designs with superior low-dimensional properties are highly required in computer experiments.Strong orthogonal arrays(SOAs)represent a class of such designs that outperform ordinary orthogonal arrays in their stratification properties within low dimensions.Nevertheless,current methods for constructing high-strength SOAs are rare,and they typically rely on regular designs,thereby limiting the number of runs in the final arrays to prime powers.This study presents new construction methods for three types of SOAs:SOAs of strength three,column-orthogonal SOAs(OSOAs)of strength three and three minus.The resulting designs have run sizes of twice an odd prime power without replications,filling the gaps in run sizes left by existing constructions.The projection properties of Addelman–Kempthorne orthogonal arrays are instrumental in the development of these construction methods.
基金supported by the National Natural Science Foundation of China(No.51905543)。
文摘This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lactic acid)/thermoplastic polyurethane(PLA/TPU)matrix.Specifically,using a 70 wt%/30 wt%PLA/TPU matrix and an L_(9)(3^(2))orthogonal design,composites were evaluated via morphology,shape memory,mechanical tests,and multi-criteria analysis.Moderate DCP enhanced crosslinking,improving storage modulus and thermal stability,while excessive DCP caused brittleness.Furthermore,MAH-g-PE effectively improved interfacial compatibility,and its synergy with DCP was dosage-dependent.Consequently,Sample 5 achieved optimal performance,exhibiting uniform fracture morphology,a shape fixation rate of98.8%with the fastest recovery,and balanced strength-ductility.Multi-criteria analysis identified elongation at break and recovery time as the top contributing factors,with consistent rankings validated by Spearman analysis(ρ=0.833,p<0.01).In summary,adjusting DCP and MAH-g-PE contents effectively modulates the crosslinking structure and interfacial properties of PLA/TPU composites,providing a viable strategy for developing high-performance,tunable 4D printing materials.
基金Supported by the Key Project from Department of Science and Technology of Heilongjiang Province(GA06B102-3-4)the Key Project from Heilongjiang Provincial Reclamation General Administration(HNKXIV-01-01-02)~~
文摘[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves by CTAB method as the template,PCR system was optimized by L16(45)orthogonal design.[Result] Clear bands were amplified from 16 different combinations,but the amplification effects and yields had difference.The most economic and applicable system was as follows:20 ng DNA template,150 μmol/L dNT...
基金the financial support from the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYLX_0399)
文摘Influence of multiple structural parameters on the performance of a gun launch system driven by highpressure reactive gases is important for structural design and performance adjustment.A coupled lumped parameter model was utilized to predict the propellant combustion,and a dynamic finite element method was applied to approximate the mechanical interactions between the projectile and the barrel.The combustion and the mechanical interactions were coupled through a user subroutine interface in ABAQUS.The correctness and the capability of the finite element approximations in capturing small structural changes were validated by comparing predicted resistance with experiments.Based on the coupled model,the influence of structural parameters of a medium-caliber gun on the system performance was investigated.In order to reduce the research costs,orthogonal tests were designed to investigate the comprehensive effects of the parameters.According to statistical analysis,the important order of the structural parameters on the launching process was obtained.The results indicate that the influence of the width of the rotating band stands out among the studied parameters in the gun.The work provides a method to investigate the influence of multiple parameters on system performance and gives guidance for controlling the system performance.
基金supported by National Natural Science Foundation of China(No.21067004)Research Fund for the Doctoral Program of Jiangxi University of Science and Technology(22020)
文摘Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9（3）4], including the ratio of buffer solution （Na2B4O7· 10H2O） to raw material, concentration of Fructus Gardeniae in extracting solution, extraction time and pH of buffer solution. An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample. Results The maximum extraction yield of the crude extract was 5.0533 （mg/g） after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4%, the concentration of Fructus Gardeniae in the extraction solution was 1/12 （g/mL）, and pH of buffer solution was 4.5. The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid, and FTIR measurements also identified the presence of flavonoid in the extracts. Conclusion This work is expected to provide a basis for further research, development, and utilization of Fructus gardenia in flavonid extraction.
基金financially supported by the Program for New Century Excellent Talents in University(NCET-12-0849)the Fundamental Research Funds for the Central Universities(13ZD12)the National Natural Science Foundation of China(No.51006034)
文摘To provide theoretical basis and practical guidance for preparing composite rods by direct continuous casting, copper-clad aluminum composite rods of external copper layer diameter 12 mm and inner aluminum core diameter 8 mm were manufactured. Orthogonal tests consisted of three factors and three levels were carried out to research the effects of melting copper temperature, continuous casting speed and nitrogen pressure on the performance of composite rods. Results showed that nitrogen pressure is the most important factor in influencing the surface quality; continuous casting speed is the most important factor in influencing copper & aluminum inter diffusion amount. Nitrogen pressure can noticeably improve the surface quality and make the rods easily be drawn out, but the surface quality does not show visible improvement when the nitrogen pressure is above 0.05 MPa. Measured by tests, the compound layer can be divided into three types according to its cladding layer degree: deficient cladding, normal cladding and excess cladding. The diameter of normal copper-clad aluminum composite rods can be successfully drawn less than 0.6 mm without annealing.
基金This work was supported by the National Natural Science Foundation of China under Grant 51605200the Senior Talent Start-up Foundation of Jiangsu University under Grant 14JDG145.
文摘A prototype centrifugal pump with a specific speed of 110 is used to investigate and optimize the performances of a turbine for power generation.Particular attention is given to the design of the internal impeller.The internal flow field is simulated in the framework of a commercial computational fluid dynamics software(ANSYS).Four geometrical parameters of the impeller are considered,i.e.,the inlet diameter,the inlet width,the blade number,and the blade angle.The optimization is carried out on the basis of a three-level approach relying on an orthogonal test method.The results of the numerical simulations show good agreement with the experimental tests under different flow conditions.In accordance with the L9(34)design table,the head and efficiency under the rated flow rate of the nine designed schemes are calculated and processed with the method of range analysis to obtain an optimized model.
基金supported by the Science and Technology Development Foundation of Shanghai Municipal Science and Technology Commission (Grant No.037252022)
文摘This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors： traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters＇ effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.
文摘The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanical tests.The orthogonal experimental design was used to study the influence of plasma-MIG welding parameters on the aluminum weld porosity.The mixed orthogonal matrix L16(4 4×2 3) and analysis of variance (ANOVA)technique were employed to optimize the welding parameters.The experimental results indicate that the effect of plasma gas flow rate is dominant,the secondary factors are MIG welding voltage,welding speed,wire feed rate and plasma current in turn.Confirmation experiments were conducted under optimum conditions and there was almost no porosity in the welded joints,thus good mechanical performance joints were obtained.
文摘The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.
基金Project supported by the National Natural Science Foundation of China(Grant No.5140130)
文摘The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-velocity MSSICG,we propose an optimization design scheme combining orthogonal experimental design(OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors(radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium-and high-velocity MSSICG.
文摘The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.
基金the National Natural Science Foundation of China(No.51375282)the China Postdoctoral Science Foundation(No.2012T50621)the Open Fund of Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures(No.2011003)
文摘The concave die design of self-pierce riveting(SPR) is of critical importance for product quality. The optimization of concave die parameters based on orthogonal test is proposed to explore the relationship between self-pierce riveted joint quality and die parameters. There are nine independent die parameter factors in orthogonal test and each factor has 4 levels. In order to evaluate the interlock and neck thickness, we carry out numerical simulations by the software DEFORM-2D. Then, the primary and secondary factors that affect the joint quality have been found out by means of range analysis. Finally, an optimization scheme is brought forward to design concave die in SPR process, which indicates that the joint has higher quality than that of former orthogonal tests.This work can be extended by a detailed mechanical and fatigue analysis for the joint quality of SPR process.
基金Supported by Talent Training and Construction Project of Professor Yang Shilin’s Team in 2017(YSL17010)
文摘[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.
基金supported by the National Key R&D Program of China(2018YFC0310500)High-Tech Ship Research Projects sponsored by the Ministry of Industry and Information Technology(2018GXB01)Yantai City school land integration development project(2019XDRHXMPT29)research and development and test platform of underwater production system。
文摘As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be carried out before launching SCMs.This study developed a testing device and an SCM test by investigating SCMs and their underwater.The testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test unit.First,the basic indices of the testing device were determined from the performance and working parameters of the SCM.Second,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was designed.Finally,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test requirements.The measurement mainly involved equipment inspection before testing and an experimental test for the SCM.The validity and feasibility of the testing device and method were simultaneously verified through an association test.
