A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The resu...A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.展开更多
In the fabrication and monitoring of parts in composite structures,which are being used more and more in a variety of engineering applications,the prediction and fatigue failure detection in composite materials is a d...In the fabrication and monitoring of parts in composite structures,which are being used more and more in a variety of engineering applications,the prediction and fatigue failure detection in composite materials is a difficult problem.This difficulty arises from several factors,such as the lack of a comprehensive investigation of the fatigue failure phenomena,the lack of a well-defined fatigue damage theory used for fatigue damage prediction,and the inhomogeneity of composites because of their multiple internal borders.This study investigates the fatigue behavior of carbon fiber reinforced with epoxy(CFRE)laminated composite plates under spectrum loading utilizing a uniqueDeep LearningNetwork consisting of a convolutional neural network(CNN).Themethod includes establishing Finite Element Model(FEM)in a plate model under a spectrum fatigue loading.Then,a CNN is trained for fatigue behavior prediction.The training phase produces promising results,showing the model’s performance with 94.21%accuracy,92.63%regression,and 91.55%F-score.To evaluate the model’s reliability,a comparison is made between fatigue data from the CNN and the FEM.It was found that the error band for this comparison is less than 0.3878MPa,affirming the accuracy and reliability of the proposed technique.The proposed method results converge with available experimental results in the literature,thus,the study suggests the broad applicability of this method to other different composite structures.展开更多
In this study,microstructure and mechanical behavior of Mg/Al composite plates with Ti foil interlayer were systematically studied,with a great emphasis on the effect of different thicknesses of Ti foil interlayer.The...In this study,microstructure and mechanical behavior of Mg/Al composite plates with Ti foil interlayer were systematically studied,with a great emphasis on the effect of different thicknesses of Ti foil interlayer.The results show that compared to 100μm thick Ti foil,10μm thick Ti foil is more prone to fracture and is evenly distributed in fragments at the interface.The introduction of Ti foil can effectively refine the grain size of Mg layers of as-rolled Mg/Al composite plates,10μm thick Ti foil has a better refining effect than 100μm thick Ti foil.Ti foil can effectively increase the yield strength(YS)and ultimate strength(UTS)of as-rolled Mg/Al composite plates,10μm thick Ti foil significantly improves the elongation(El)of Mg/Al composite plate,while 100μm thick Ti foil slightly weakens the El.After annealing at 420℃ for 0.5 h and 4 h,Ti foil can inhibit the formation of intermetallic compounds(IMCs)at the interface of Mg/Al composite plates,which effectively improves the YS,UTS and El of Mg/Al composite plates.In addition,Ti foil can also significantly enhance the interfacial shear strength(SS)of Mg/Al composite plates before and after annealing.展开更多
As-rolled titanium/steel composite plate has poor plastic deformation ability,and it is difficult to achieve synergistic deformation,especially for dissimilar metals with very different plastic deformation abilities.T...As-rolled titanium/steel composite plate has poor plastic deformation ability,and it is difficult to achieve synergistic deformation,especially for dissimilar metals with very different plastic deformation abilities.The 304/TC4 composite plate with corrugated interface was manufactured using the asymmetric rolling with local strong stress method.The changing rules of bonding strength and synergistic deformation ability of corrugated interface under different annealing process parameters were studied.The results show that in the range of 550–850℃,especially after the temperature exceeds 650℃,with increasing the annealing temperature and time,the difference of microstructure between peak and trough positions increases,and the bonding strength of the composite plate decreases gradually.Especially,the interfacial bonding strength of the plate sharply decreases at 750℃ due to the rapid growth of intermetallic compounds at the interface and the diffusion holes caused by the difference of element diffusion.The 304/TC4 composite plate has the best synergistic deformation ability when annealing at 650℃/2 h,with the elongation reaching 35%and the tensile strength decreasing to 852 MPa.High interfacial bonding strength and moderate matrix recovery are important prerequisites for synergistic deformation of composite plates.展开更多
Current research on the fabrication of rolled composite plates primarily focuses on processing and bonding mechanisms.Compared with hot-rolling technology,the electrically assisted rolling process has demonstrated exc...Current research on the fabrication of rolled composite plates primarily focuses on processing and bonding mechanisms.Compared with hot-rolling technology,the electrically assisted rolling process has demonstrated excellent performance in interfacial bonding effects.However,the influence of different current loading modes on the interfacial recombination process of composite panels varies significantly.In this study,low-frequency electrically assisted rolling was used in the first pass to pre-bond a composite plate at a low reduction rate of 15%.High-frequency electrically assisted rolling was used during the second pass,and Al/Mg alloy composite plates were obtained.The interfacial microstructure and mechanical properties of the composite plate were coordinated regulation by designing the rolling reduction rate.The results showed the interfacial morphology of the alternating distribution of the melt-diffusion layer,diffusion layer,and the formation of a new Al/Mg bonding interface.At the melt-diffusion interface,the irregular intermetallic compounds(IMCs)and the new Al/Mg bonding interface were alternately distributed,and the IMCs contained theα-Mg,Mg17Al12,and Mg2Al3 phases.In addition,an extremely high shear strength of 78.26 MPa was achieved.Adhesion of the Mg alloy matrix was observed on the fracture surface of the Al alloy side.The high shear strength was mainly attributed to the formation of a unique interfacial structure and the appearance of a melt-diffusion layer.Compared to the diffusion-reduction interface,the regular rectangular IMCs and the new Al/Mg bonding interface were alternately distributed,and the IMCs consisted of the Mg17Al12 and Mg2Al3 phases.The shear test results showed that the shear strength of the interface reached 68.69 MPa,and a regular distribution of the Mg alloy matrix with dimples and the Al alloy matrix with a necking zone was observed on the fracture surface of the Al side.Tensile strength test results revealed a maximum value of 316.86 MPa for the Al/Mg alloy composite plate.The tensile and interfacial bonding strengths can be synchronously enhanced by coordinating the regulation of the interfacial structure.This study proposes a new electrically assisted rolling technology that is useful for the fabrication of composite plates with excellent mechanical properties.展开更多
An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the bucklin...An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.展开更多
The AZ31/GW103 K bimetallic composite plates were prepared by co-extrusion of different combination types(sandwich extrusion type and double semicircle extrusion type),and effects of different extrusion combination ty...The AZ31/GW103 K bimetallic composite plates were prepared by co-extrusion of different combination types(sandwich extrusion type and double semicircle extrusion type),and effects of different extrusion combination types on the microstructure and mechanical properties of bimetallic composite plates were systematically investigated.The results show that both the AZ31/GW103 K bimetallic composite plates prepared by different extrusion combination types have good metallurgical bonding,and changing the combination type does not affect the thickness of the interfacial transition layer of composite plates.Compared with the monolithic AZ31 and GW103 K extruded plates,co-extrusion can promote the dynamic recrystallization(DRX)of AZ31 and GW103 K components in composite plates,and double semicircular extrusion type has a better promotion effect on the DRX than sandwich extrusion type.In addition,the texture of AZ31 in both monolithic AZ31 and AZ31/GW103 K/AZ31(A/G/A)plates is a typical(0002)basal texture,while that in the AZ31/GW103 K(A/G)composite plate shifts to the tangent direction(TD)of extruded plate.Compared with the monolithic AZ31 extruded plate,both the yield strength and tensile strength of A/G and A/G/A bimetallic composite plates are significantly improved.The strength of A/G/A composite plate is higher than that of A/G composite plate,but its elongation is worse.Meanwhile,co-extrusion reduces the dislocation density of AZ31 and GW 103 K components in composite plates,and different extrusion combination types also affect the dislocation density.展开更多
Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrat...Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range.展开更多
Scale effects are studied on the buckling behavior of bilayer composite plates under non-uniform uniaxial compression via the nonlocal theory. Each isotropic plate is composed of a material that is different from othe...Scale effects are studied on the buckling behavior of bilayer composite plates under non-uniform uniaxial compression via the nonlocal theory. Each isotropic plate is composed of a material that is different from others, and the adhesive between the plates is modeled as the Winkler elastic medium. According to the symmetry, effects of the Winkler non-dimensional parameter, the thickness ratio, the ratio of Young＇s moduli, and the aspect ratio are also considered on the buckling problem of bilayer plates, where only the top plate is under the uniaxial compression. Numerical examples show that the Winkler elastic coefficient, the thickness ratio, and the ratio of Young＇s moduli play decisive roles in the buckling behavior. Nonlocal effect is significant when the high-order buckling mode occurs or the aspect ratio is small.展开更多
By introducing the Hamilton theory and algorithms into the problems of laminated composite plates andshells, the Hamiltion type generalized variational principle is established, and the Hamilton canonical equations an...By introducing the Hamilton theory and algorithms into the problems of laminated composite plates andshells, the Hamiltion type generalized variational principle is established, and the Hamilton canonical equations andthe boundary conditions for the static and elastoplastic analysis of composite plates are presented. With thetransformation of phase variables, the Hamilton canonical equations and their boundary conditions for thecylindrical shells and doubly curved shells in the curvilinear coordinate are given.展开更多
Two types of titanium/steel composite plates with the same thickness were manufactured by parallel explosive welding and double vertical explosive welding and rolling, respectively. The comparative analysis of microst...Two types of titanium/steel composite plates with the same thickness were manufactured by parallel explosive welding and double vertical explosive welding and rolling, respectively. The comparative analysis of microstructure showed that the interface of double vertical explosive welding plate （B plate） tended to be straight while the interface of parallel explosive welding plate （A plate） was wavy bonding. Defects near the interface of B plate were extruded, and the thickness of the diffusion layer of B plate was thicker under the effects of preheating temperature and press-working. Comparative tests of mechanical properties indicated that the tensile shear strength of B plate was lower while its micro-hardness was higher. Specimens of these two types of plates were neither separated nor cracked after bending up to 180° in the three-point bending test. From the microstructural observation of tensile fracture characteristics, A plate had strong toughness fracture while B plate had mainly ductile fracture with cleavage fracture as the supplement. Macroscopically, the tensile strength of the latter was 7.9% less than that of the former. However, both satisfied the Chinese standard of tensile strength.展开更多
Al/steel composite plate has a wide application prospect,but great differences in properties between Al and steel are observed.It is difficult to obtain high bonding strength by the traditional cold roll bonding proce...Al/steel composite plate has a wide application prospect,but great differences in properties between Al and steel are observed.It is difficult to obtain high bonding strength by the traditional cold roll bonding process.Al/steel composite plate was thus prepared by cold roll bonding at a reduction rate of 60%after oxidation treatment on the surface to be composited on the steel side.The heat treatment of holding at 400℃ for 1 h and cooling with the furnace was then adopted.The bonding strength,microstructure,and properties of the Al/steel composite plate before and after annealing were analysed and compared through shear test,bending test,tensile test,and micro-characterization.Results show that the shear strengths of the interface before and after annealing are 100 and 80 MPa,respectively.Although the shear strength of the annealed Al/steel composite plate decreases,the bending and overall tensile properties of the composite plate are improved,showing better mechanical properties.展开更多
Free vibration analysis of symmetrically laminated composite plates resting on Pasternak elastic support and coupled with an ideal, incompressible and inviscid fluid is the objective of the present work. The fluid dom...Free vibration analysis of symmetrically laminated composite plates resting on Pasternak elastic support and coupled with an ideal, incompressible and inviscid fluid is the objective of the present work. The fluid domain is considered to be infinite in the length direction but bounded in the depth and width directions. In order to derive the eigenvalue equation, Rayleigh-Ritz method is applied for the fluid-plate-foundation system. The efficiency of the method is proved by comparison studies with those reported in the open literature. At the end, parametric studies are carried out to examine the impact of different parameters on the natural frequencies.展开更多
In this work,Mg/Al composite plates with different thickness ratios were prepared by the asymmetrical rolling process with differential temperature rolls and isothermal symmetrical rolling.Microstructural evolution an...In this work,Mg/Al composite plates with different thickness ratios were prepared by the asymmetrical rolling process with differential temperature rolls and isothermal symmetrical rolling.Microstructural evolution and mechanical properties of matrix and composite materials with different thicknesses were analyzed.Influence of thickness ratios on the coordinated deformability of heterogeneous metals and interface toughness under the action of temperature gradient and shear force was investigated.Results show that the relative deformation rates of matrix and composite materials converge gradually under the influence of work hardening of Mg/Al layer.The Mg layer is mainly DRXed grains and texture intensity gradually weakens with increasing thickness ratio.The Al layer is mostly dominated by subgrains and deformed grains,which have a strong correlation with thickness ratio.Strength and plasticity of composites first increase and then decrease with increasing thickness ratio.Fracture of composite plate occurs in intermetallic compounds(IMCs).Thickness of IMCs has a strong positive correlation with thickness ratio.When the thickness ratio of AZ31B/Al6061 for 5,the relative thickness of IMCs is the largest and the relative bonding strength is the smallest.When the thickness ratio of AZ31B/Al6061 for 3,there is no element aggregation in IMCs,and the comprehensive mechanical properties of composite plate are comparatively better.展开更多
This work explores the postbuckling behavior of a marine stifened composite plate in the presence of initial imperfections.The imperfection shapes are derived from buckling mode shapes and their combinations.Thereafte...This work explores the postbuckling behavior of a marine stifened composite plate in the presence of initial imperfections.The imperfection shapes are derived from buckling mode shapes and their combinations.Thereafter,these imperfection shapes are applied to the model,and nonlinear large defection fnite element and progressive failure analyses are performed in ANSYS 18.2 software.The Hashin failure criterion is employed to model the progressive failure in the stifened composite plate.The efect of the initial geometric imperfection on the stifened composite plate is investigated by considering various imperfection patterns and magnitudes.Results show that when the magnitude of the imperfection is 20 mm,the ultimate strength of the stifened composite plate decreases by 31%.Moreover,global imperfection shapes are found to be fundamental in determining the ultimate strength of stifened composite plates and their postbuckling.展开更多
This paper presents an analysis of the active control of random vibration for lami- nated composite plates using piezoelectric fiber reinforced composites （PFRC）. With Hamilton＇s principle and the Rayleigh-Ritz met...This paper presents an analysis of the active control of random vibration for lami- nated composite plates using piezoelectric fiber reinforced composites （PFRC）. With Hamilton＇s principle and the Rayleigh-Ritz method, the equation of motion for the resulting electromechani- cal coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the suppression of random vibration. The power spectral density and mean- square displacements of the random vibration for laminated plates under different control gains are simulated and the validity of the present control strategy is confirmed. The effect of piezoelec- tric fiber orientation in the PFRC layer on the random vibration suppression is also investigated. The analytical methodology can be expanded to other kinds of random vibration.展开更多
Two dissimilar steel plates,structural steel and mild steel,were joined by explosion welding to form a composite.The composite was then heat-treated by quenching at 840℃ for 30 min followed by tempering at 200℃ for ...Two dissimilar steel plates,structural steel and mild steel,were joined by explosion welding to form a composite.The composite was then heat-treated by quenching at 840℃ for 30 min followed by tempering at 200℃ for 3 h.The microstructure was investigated under an optical microscope and a scanning electron microscope.The mechanical properties were measured using Vickers microhardness and Charpy impact tests.The results show a deformed interface with typical wave features at the welding zone,but no defects were observed.Moreover,the ferrite in the parent plate in the weld zone was elongated due to the strong plastic deformation from the explosion.After heat treatment,the hardness of the flyer plate(structural steel)was over HV0.2800,while that of the parent plate(mild steel)was HV0.2200.The increase in hardness was due to the presence of martensite.Moreover,the average impact energy was increased from 18.5 to 44.0 J following heat treatment;this is because of the formation of recrystallized grains at the weld interface,which is due to the dynamic recovery and local recrystallization,and the strong elemental diffusion that occurred between the two plates.展开更多
The bending and stress analysis of a functionally graded polymer composite plate reinforced with graphene platelets are studied in this paper.The governing equations are derived by using principle of virtual work for ...The bending and stress analysis of a functionally graded polymer composite plate reinforced with graphene platelets are studied in this paper.The governing equations are derived by using principle of virtual work for a plate which is rested on Pasternak’s foundation.Sinusoidal shear deformation theory is used to describe displacement field.Four different distribution patterns are employed in our analysis.The analytical solution is presented for a functionally graded plate to investigate the influence of important parameters.The numerical results are presented to show the deflection and stress results of the problem for four employed patterns in terms of geometric parameters such as number of layers,weight fraction and two parameters of Pasternak’s foundation.展开更多
Researches on parity-time(PT)symmetry in acoustic field can provide an efficient platform for controlling the travelling acoustic waves with balanced loss and gain.Here,we report a feasible design of PT-symmetric syst...Researches on parity-time(PT)symmetry in acoustic field can provide an efficient platform for controlling the travelling acoustic waves with balanced loss and gain.Here,we report a feasible design of PT-symmetric system constructed by piezoelectric composite plates with two different active external circuits.By judiciously adjusting the resistances and inductances in the external circuits,we obtain the exceptional point due to the spontaneous breaking of PT symmetry at the desired frequencies and can observe the unidirectional invisibility.Moreover,the system can be at PT exact phase or broken phase at the same frequency in the same structure by merely adjusting the external circuits,which represents the active control that makes the acoustic manipulation more convenient.Our study may provide a feasible way for manipulating acoustic waves and inspire the application of piezoelectric composite materials in acoustic structures.展开更多
TA1 P-Ti/AA6061 composite plate was produced by oxidizing the surface of the titanium plate and adopting a cold roll bonding process.The results revealed that the oxide film(Ti6O)prepared on the surface of TA1 pure ti...TA1 P-Ti/AA6061 composite plate was produced by oxidizing the surface of the titanium plate and adopting a cold roll bonding process.The results revealed that the oxide film(Ti6O)prepared on the surface of TA1 pure titanium was easy to crack during the cold roll bonding,thereby promoting the formation of an effective mechanical interlock at the interface,which can effectively reduce the minimum reduction rate of the composite plates produced by cold rolling of titanium and aluminium plates.Moreover,the composite plate subjected to oxidation treatment exhibited high shear strength,particularly at a 43%reduction rate,achieving a commendable value of 117 MPa.Based on oxidation treatment and different reduction rates,the annealed composite plates at temperatures of 400,450,and 500°C displayed favorable resistance to interface delamination,highlighting their remarkable strength-plasticity compatibility as evidenced by a maximum elongation of 31.845%.展开更多
基金supported by Guangdong Major Project of Basic and Applied Basic Research, China (No. 2020B0301030006)Fundamental Research Funds for the Central Universities, China (No. SWU-XDJH202313)+1 种基金Chongqing Postdoctoral Science Foundation Funded Project, China (No. 2112012728014435)the Chongqing Postgraduate Research and Innovation Project, China (No. CYS23197)。
文摘A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.
文摘In the fabrication and monitoring of parts in composite structures,which are being used more and more in a variety of engineering applications,the prediction and fatigue failure detection in composite materials is a difficult problem.This difficulty arises from several factors,such as the lack of a comprehensive investigation of the fatigue failure phenomena,the lack of a well-defined fatigue damage theory used for fatigue damage prediction,and the inhomogeneity of composites because of their multiple internal borders.This study investigates the fatigue behavior of carbon fiber reinforced with epoxy(CFRE)laminated composite plates under spectrum loading utilizing a uniqueDeep LearningNetwork consisting of a convolutional neural network(CNN).Themethod includes establishing Finite Element Model(FEM)in a plate model under a spectrum fatigue loading.Then,a CNN is trained for fatigue behavior prediction.The training phase produces promising results,showing the model’s performance with 94.21%accuracy,92.63%regression,and 91.55%F-score.To evaluate the model’s reliability,a comparison is made between fatigue data from the CNN and the FEM.It was found that the error band for this comparison is less than 0.3878MPa,affirming the accuracy and reliability of the proposed technique.The proposed method results converge with available experimental results in the literature,thus,the study suggests the broad applicability of this method to other different composite structures.
基金supported by the National Key Research and Development Program of China(2022YFB3708400)the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030006)+4 种基金the Youth Talent Support Programme of Guangdong Provincial Association for Science and Technology(SKXRC202301)the Guangdong Academy of Science Fund(2020GDASYL-20200101001,2023GDASQNRC-0210,2023GDASQNRC-0321)the Guangdong Science and Technology plan project(2023A0505030002)the GINM’Special Project of Science and Technology Development(2023GINMZX-202301020108)Evaluation Project of Guangdong Provincial Key Laboratory(2023B1212060043).
文摘In this study,microstructure and mechanical behavior of Mg/Al composite plates with Ti foil interlayer were systematically studied,with a great emphasis on the effect of different thicknesses of Ti foil interlayer.The results show that compared to 100μm thick Ti foil,10μm thick Ti foil is more prone to fracture and is evenly distributed in fragments at the interface.The introduction of Ti foil can effectively refine the grain size of Mg layers of as-rolled Mg/Al composite plates,10μm thick Ti foil has a better refining effect than 100μm thick Ti foil.Ti foil can effectively increase the yield strength(YS)and ultimate strength(UTS)of as-rolled Mg/Al composite plates,10μm thick Ti foil significantly improves the elongation(El)of Mg/Al composite plate,while 100μm thick Ti foil slightly weakens the El.After annealing at 420℃ for 0.5 h and 4 h,Ti foil can inhibit the formation of intermetallic compounds(IMCs)at the interface of Mg/Al composite plates,which effectively improves the YS,UTS and El of Mg/Al composite plates.In addition,Ti foil can also significantly enhance the interfacial shear strength(SS)of Mg/Al composite plates before and after annealing.
基金supported by the Major Program of National Natural Science Foundation of China(U22A20188)the Natural Science Foundation of Shanxi Province(202303021224002)+1 种基金the special fund for Science and Technology Innovation Teams of Shanxi Province(202304051001025)the Open Research Fund from the Hai’an and Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute(2023HA-TYUTKFYF036).
文摘As-rolled titanium/steel composite plate has poor plastic deformation ability,and it is difficult to achieve synergistic deformation,especially for dissimilar metals with very different plastic deformation abilities.The 304/TC4 composite plate with corrugated interface was manufactured using the asymmetric rolling with local strong stress method.The changing rules of bonding strength and synergistic deformation ability of corrugated interface under different annealing process parameters were studied.The results show that in the range of 550–850℃,especially after the temperature exceeds 650℃,with increasing the annealing temperature and time,the difference of microstructure between peak and trough positions increases,and the bonding strength of the composite plate decreases gradually.Especially,the interfacial bonding strength of the plate sharply decreases at 750℃ due to the rapid growth of intermetallic compounds at the interface and the diffusion holes caused by the difference of element diffusion.The 304/TC4 composite plate has the best synergistic deformation ability when annealing at 650℃/2 h,with the elongation reaching 35%and the tensile strength decreasing to 852 MPa.High interfacial bonding strength and moderate matrix recovery are important prerequisites for synergistic deformation of composite plates.
基金Supported by National Natural Science Foundation of China(Grant Nos.52075360,52275360,51805359).
文摘Current research on the fabrication of rolled composite plates primarily focuses on processing and bonding mechanisms.Compared with hot-rolling technology,the electrically assisted rolling process has demonstrated excellent performance in interfacial bonding effects.However,the influence of different current loading modes on the interfacial recombination process of composite panels varies significantly.In this study,low-frequency electrically assisted rolling was used in the first pass to pre-bond a composite plate at a low reduction rate of 15%.High-frequency electrically assisted rolling was used during the second pass,and Al/Mg alloy composite plates were obtained.The interfacial microstructure and mechanical properties of the composite plate were coordinated regulation by designing the rolling reduction rate.The results showed the interfacial morphology of the alternating distribution of the melt-diffusion layer,diffusion layer,and the formation of a new Al/Mg bonding interface.At the melt-diffusion interface,the irregular intermetallic compounds(IMCs)and the new Al/Mg bonding interface were alternately distributed,and the IMCs contained theα-Mg,Mg17Al12,and Mg2Al3 phases.In addition,an extremely high shear strength of 78.26 MPa was achieved.Adhesion of the Mg alloy matrix was observed on the fracture surface of the Al alloy side.The high shear strength was mainly attributed to the formation of a unique interfacial structure and the appearance of a melt-diffusion layer.Compared to the diffusion-reduction interface,the regular rectangular IMCs and the new Al/Mg bonding interface were alternately distributed,and the IMCs consisted of the Mg17Al12 and Mg2Al3 phases.The shear test results showed that the shear strength of the interface reached 68.69 MPa,and a regular distribution of the Mg alloy matrix with dimples and the Al alloy matrix with a necking zone was observed on the fracture surface of the Al side.Tensile strength test results revealed a maximum value of 316.86 MPa for the Al/Mg alloy composite plate.The tensile and interfacial bonding strengths can be synchronously enhanced by coordinating the regulation of the interfacial structure.This study proposes a new electrically assisted rolling technology that is useful for the fabrication of composite plates with excellent mechanical properties.
基金Vietnam National Foundation for Science and Technology Development(NAFOSTED)under Grant number 107.02-2019.330.
文摘An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.
基金financially supported by the National Natural Science Foundation of China(Nos.U1810122,U1710118,52174362 and 51975207)the Yantai High-End Talent Introduction"Double Hundred Plan"(2021)+3 种基金the Talent Training Program for Shandong Province Higher Educational Youth Innovative Teams(2019)the Key Research and Development Program of Shanxi Province(Nos.201903D421076 and 201803D421086)the Innovative Talents of Higher Education Institutions of Shanxi(2018)the Central Government Guided Local Science and Technology Development Projects(No.YDZJSX2021A010)。
文摘The AZ31/GW103 K bimetallic composite plates were prepared by co-extrusion of different combination types(sandwich extrusion type and double semicircle extrusion type),and effects of different extrusion combination types on the microstructure and mechanical properties of bimetallic composite plates were systematically investigated.The results show that both the AZ31/GW103 K bimetallic composite plates prepared by different extrusion combination types have good metallurgical bonding,and changing the combination type does not affect the thickness of the interfacial transition layer of composite plates.Compared with the monolithic AZ31 and GW103 K extruded plates,co-extrusion can promote the dynamic recrystallization(DRX)of AZ31 and GW103 K components in composite plates,and double semicircular extrusion type has a better promotion effect on the DRX than sandwich extrusion type.In addition,the texture of AZ31 in both monolithic AZ31 and AZ31/GW103 K/AZ31(A/G/A)plates is a typical(0002)basal texture,while that in the AZ31/GW103 K(A/G)composite plate shifts to the tangent direction(TD)of extruded plate.Compared with the monolithic AZ31 extruded plate,both the yield strength and tensile strength of A/G and A/G/A bimetallic composite plates are significantly improved.The strength of A/G/A composite plate is higher than that of A/G composite plate,but its elongation is worse.Meanwhile,co-extrusion reduces the dislocation density of AZ31 and GW 103 K components in composite plates,and different extrusion combination types also affect the dislocation density.
基金Project(51508562)supported by the National Natural Science Foundation of ChinaProject(ZK18-03-49)supported by the Scientific Research Program of National University of Defense Technology,China
文摘Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range.
基金Project supported by the National Natural Science Foundation of China(Nos.10632040 and 11472163)the National Key Basic Research Project of China(No.2014CB04623)the Shanghai Municipal Commission of Eduction(No.13ZZ067)
文摘Scale effects are studied on the buckling behavior of bilayer composite plates under non-uniform uniaxial compression via the nonlocal theory. Each isotropic plate is composed of a material that is different from others, and the adhesive between the plates is modeled as the Winkler elastic medium. According to the symmetry, effects of the Winkler non-dimensional parameter, the thickness ratio, the ratio of Young＇s moduli, and the aspect ratio are also considered on the buckling problem of bilayer plates, where only the top plate is under the uniaxial compression. Numerical examples show that the Winkler elastic coefficient, the thickness ratio, and the ratio of Young＇s moduli play decisive roles in the buckling behavior. Nonlocal effect is significant when the high-order buckling mode occurs or the aspect ratio is small.
文摘By introducing the Hamilton theory and algorithms into the problems of laminated composite plates andshells, the Hamiltion type generalized variational principle is established, and the Hamilton canonical equations andthe boundary conditions for the static and elastoplastic analysis of composite plates are presented. With thetransformation of phase variables, the Hamilton canonical equations and their boundary conditions for thecylindrical shells and doubly curved shells in the curvilinear coordinate are given.
基金This project was sponsored by the National Natural Science Foundation of China （No. 51541112） and Special Fund Achievement Transformation Projects in Jiangsu of China （No. BA2012030）.
文摘Two types of titanium/steel composite plates with the same thickness were manufactured by parallel explosive welding and double vertical explosive welding and rolling, respectively. The comparative analysis of microstructure showed that the interface of double vertical explosive welding plate （B plate） tended to be straight while the interface of parallel explosive welding plate （A plate） was wavy bonding. Defects near the interface of B plate were extruded, and the thickness of the diffusion layer of B plate was thicker under the effects of preheating temperature and press-working. Comparative tests of mechanical properties indicated that the tensile shear strength of B plate was lower while its micro-hardness was higher. Specimens of these two types of plates were neither separated nor cracked after bending up to 180° in the three-point bending test. From the microstructural observation of tensile fracture characteristics, A plate had strong toughness fracture while B plate had mainly ductile fracture with cleavage fracture as the supplement. Macroscopically, the tensile strength of the latter was 7.9% less than that of the former. However, both satisfied the Chinese standard of tensile strength.
基金the National Key Research and Development Program of China(Grant No.2018YFA0707300)the National Natural Science Foundation of China(Grant Nos.52075472 and 52004242)the National Science Foundation of Hebei Province(Grant No.E2020203001).
文摘Al/steel composite plate has a wide application prospect,but great differences in properties between Al and steel are observed.It is difficult to obtain high bonding strength by the traditional cold roll bonding process.Al/steel composite plate was thus prepared by cold roll bonding at a reduction rate of 60%after oxidation treatment on the surface to be composited on the steel side.The heat treatment of holding at 400℃ for 1 h and cooling with the furnace was then adopted.The bonding strength,microstructure,and properties of the Al/steel composite plate before and after annealing were analysed and compared through shear test,bending test,tensile test,and micro-characterization.Results show that the shear strengths of the interface before and after annealing are 100 and 80 MPa,respectively.Although the shear strength of the annealed Al/steel composite plate decreases,the bending and overall tensile properties of the composite plate are improved,showing better mechanical properties.
文摘Free vibration analysis of symmetrically laminated composite plates resting on Pasternak elastic support and coupled with an ideal, incompressible and inviscid fluid is the objective of the present work. The fluid domain is considered to be infinite in the length direction but bounded in the depth and width directions. In order to derive the eigenvalue equation, Rayleigh-Ritz method is applied for the fluid-plate-foundation system. The efficiency of the method is proved by comparison studies with those reported in the open literature. At the end, parametric studies are carried out to examine the impact of different parameters on the natural frequencies.
基金supported by the National Natural Science Foundation of China(U1910213 and 52105388)Technological Innovation Talent Team Special Plan of Shanxi Province(202204051002002)+2 种基金Key Research and Development Program of Shanxi Province(202102050201005)Program for the Innovative Talents of Higher Education Institutions of Shanxi,Postgraduate Education Innovation Project of Shanxi Province(2020BY111)Shanxi Province patent promotion and implementation funding special projects(2019013).
文摘In this work,Mg/Al composite plates with different thickness ratios were prepared by the asymmetrical rolling process with differential temperature rolls and isothermal symmetrical rolling.Microstructural evolution and mechanical properties of matrix and composite materials with different thicknesses were analyzed.Influence of thickness ratios on the coordinated deformability of heterogeneous metals and interface toughness under the action of temperature gradient and shear force was investigated.Results show that the relative deformation rates of matrix and composite materials converge gradually under the influence of work hardening of Mg/Al layer.The Mg layer is mainly DRXed grains and texture intensity gradually weakens with increasing thickness ratio.The Al layer is mostly dominated by subgrains and deformed grains,which have a strong correlation with thickness ratio.Strength and plasticity of composites first increase and then decrease with increasing thickness ratio.Fracture of composite plate occurs in intermetallic compounds(IMCs).Thickness of IMCs has a strong positive correlation with thickness ratio.When the thickness ratio of AZ31B/Al6061 for 5,the relative thickness of IMCs is the largest and the relative bonding strength is the smallest.When the thickness ratio of AZ31B/Al6061 for 3,there is no element aggregation in IMCs,and the comprehensive mechanical properties of composite plate are comparatively better.
文摘This work explores the postbuckling behavior of a marine stifened composite plate in the presence of initial imperfections.The imperfection shapes are derived from buckling mode shapes and their combinations.Thereafter,these imperfection shapes are applied to the model,and nonlinear large defection fnite element and progressive failure analyses are performed in ANSYS 18.2 software.The Hashin failure criterion is employed to model the progressive failure in the stifened composite plate.The efect of the initial geometric imperfection on the stifened composite plate is investigated by considering various imperfection patterns and magnitudes.Results show that when the magnitude of the imperfection is 20 mm,the ultimate strength of the stifened composite plate decreases by 31%.Moreover,global imperfection shapes are found to be fundamental in determining the ultimate strength of stifened composite plates and their postbuckling.
基金Project supported by the National Natural Science Foundation of China(Nos.11502159 and 11390362)Natural Science Foundation of Shanxi(No.2015021014)+4 种基金the Top Young Academic Leaders of High Learning Institutions of ShanxiShanxi Scholarship Council of Chinathe Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provincethe Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry
文摘This paper presents an analysis of the active control of random vibration for lami- nated composite plates using piezoelectric fiber reinforced composites （PFRC）. With Hamilton＇s principle and the Rayleigh-Ritz method, the equation of motion for the resulting electromechani- cal coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the suppression of random vibration. The power spectral density and mean- square displacements of the random vibration for laminated plates under different control gains are simulated and the validity of the present control strategy is confirmed. The effect of piezoelec- tric fiber orientation in the PFRC layer on the random vibration suppression is also investigated. The analytical methodology can be expanded to other kinds of random vibration.
基金financially supported by the State Key Laboratory of Solidification Processing of Northwestern Polytechnical University(2019-QZ-01)。
文摘Two dissimilar steel plates,structural steel and mild steel,were joined by explosion welding to form a composite.The composite was then heat-treated by quenching at 840℃ for 30 min followed by tempering at 200℃ for 3 h.The microstructure was investigated under an optical microscope and a scanning electron microscope.The mechanical properties were measured using Vickers microhardness and Charpy impact tests.The results show a deformed interface with typical wave features at the welding zone,but no defects were observed.Moreover,the ferrite in the parent plate in the weld zone was elongated due to the strong plastic deformation from the explosion.After heat treatment,the hardness of the flyer plate(structural steel)was over HV0.2800,while that of the parent plate(mild steel)was HV0.2200.The increase in hardness was due to the presence of martensite.Moreover,the average impact energy was increased from 18.5 to 44.0 J following heat treatment;this is because of the formation of recrystallized grains at the weld interface,which is due to the dynamic recovery and local recrystallization,and the strong elemental diffusion that occurred between the two plates.
基金the University of Kashan.(Grant Number:467893/0655)。
文摘The bending and stress analysis of a functionally graded polymer composite plate reinforced with graphene platelets are studied in this paper.The governing equations are derived by using principle of virtual work for a plate which is rested on Pasternak’s foundation.Sinusoidal shear deformation theory is used to describe displacement field.Four different distribution patterns are employed in our analysis.The analytical solution is presented for a functionally graded plate to investigate the influence of important parameters.The numerical results are presented to show the deflection and stress results of the problem for four employed patterns in terms of geometric parameters such as number of layers,weight fraction and two parameters of Pasternak’s foundation.
基金supported by the National Key R&D Program of China(Grant No.2017YFA0303700)the National Natural Science Foundation of China(Grant Nos.11634006,11934009,and 12074184)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20191245)the State Key Laboratory of Acoustics,Chinese Academy of Sciences.
文摘Researches on parity-time(PT)symmetry in acoustic field can provide an efficient platform for controlling the travelling acoustic waves with balanced loss and gain.Here,we report a feasible design of PT-symmetric system constructed by piezoelectric composite plates with two different active external circuits.By judiciously adjusting the resistances and inductances in the external circuits,we obtain the exceptional point due to the spontaneous breaking of PT symmetry at the desired frequencies and can observe the unidirectional invisibility.Moreover,the system can be at PT exact phase or broken phase at the same frequency in the same structure by merely adjusting the external circuits,which represents the active control that makes the acoustic manipulation more convenient.Our study may provide a feasible way for manipulating acoustic waves and inspire the application of piezoelectric composite materials in acoustic structures.
基金supports from the National Natural Science Foundation of China(Nos.52075472,52004242)the National Key Research and Development Program of China(No.2018YFA0707300)the Natural Science Foundation of Hebei Province,China(No.E2020203001)。
文摘TA1 P-Ti/AA6061 composite plate was produced by oxidizing the surface of the titanium plate and adopting a cold roll bonding process.The results revealed that the oxide film(Ti6O)prepared on the surface of TA1 pure titanium was easy to crack during the cold roll bonding,thereby promoting the formation of an effective mechanical interlock at the interface,which can effectively reduce the minimum reduction rate of the composite plates produced by cold rolling of titanium and aluminium plates.Moreover,the composite plate subjected to oxidation treatment exhibited high shear strength,particularly at a 43%reduction rate,achieving a commendable value of 117 MPa.Based on oxidation treatment and different reduction rates,the annealed composite plates at temperatures of 400,450,and 500°C displayed favorable resistance to interface delamination,highlighting their remarkable strength-plasticity compatibility as evidenced by a maximum elongation of 31.845%.
