Finite Element Simulation And Experimental Study On Plastic Instability Of Composite Plate Rolling

Metal laminated composite materials can combine the excellent properties of various materials and synthesize the properties and characteristics of each group of metals,which greatly meet higher and higher people's requirements for properties of materials and truly achieve complementary advantages.Therefore,they are widely used in high and new technology fields such as machinery,aerospace,electronics and medical treatment.Therefore,it is great practical value to develop metal composites with better performance and improve the existing production process.Although metal laminated composite materials have many advantages,but due to the different material properties of each compound layer,the deformation of the composite layer of metal laminated composites in cold rolling process will cause periodic necking,bending to the direction of thickness or fracture phenomena which greatly limits the performance of metal laminated composites.Because metal composite plate rolling is a highly nonlinear and complex process,it is very difficult to study the stress and deformation of the composite layers during the rolling process.This article adopts the method of finite element simulation and experimental research,using ABAQUS finite element analysis software to simulate the rolling process of two metal laminated composite plates with different material properties,discussing the mechanism of plastic instability of metal laminated composite plate after rolling,and the influence of different rolling conditions on the plastic instability of composite plate after rolling is further analyzed.Then the results of finite element analysis are compared and verified by rolling experiment of steel/aluminum composite plate.First of all,based on commercial finite element analysis software ABAQUS,the finite element model of aluminum/steel/aluminum three-layer symmetric composite plate was established,and the periodic necking phenomenon between composite plates after rolling was successfully simulated.Based on the analysis of the Mises stress cloud map of the deformation zone during rolling,the instability of the composite plate occurred three times from the rolling entrance to the rolling exit.From the stress cloud map of the rolling direction in the deformation zone during the rolling process,the tensile stress of the rolling direction of the composite plate steel layer fluctuates from the entrance to the exit.After further analysis,it is found that the entire rolling process is due to the uncoordinated deformation of the steel layer and the aluminum layer of the composite plate,resulting in the continuous change of tensile stress on the rolling direction of the steel layer,resulting in three times of necking of the steel layer in the rolling process,and finally resulting in the formation of periodic necking of the composite plate after rolling.Then,in the finite element model of three-layer symmetrical composite plate rolling,on the plastic instability of composite plate rolling,the influences of the five factors,namely thickness ratio,yield strength,reduction rate,work hardening rate and roll diameter were simulated and analyzed under the premise of keeping other rolling parameters and rolling conditions unchanged.According to the analysis,for the thickness ratio,whether aluminum/steel/aluminum three-layer symmetric composite plate or steel/aluminum/steel three-layer symmetric composite plate,the thickened aluminum layer promotes the plastic instability of the composite plate after rolling,while the thickened steel layer inhibits the plastic instability of the composite plate after rolling.For the yield strength,increasing the yield strength difference between the inner and outer layers of the composite plate will aggravate the plastic instability of the composite plate after rolling.For the rolling down rate,increasing the rolling down rate will aggravate the plastic instability of composite plate after rolling.For the work hardening rate,no matter the aluminum layer or steel layer is increased,the plastic instability of composite plate after rolling will be suppressed.Finally,the rolling experiment of aluminum/steel/aluminum three-layer symmetric composite plate was carried out in the laboratory to study the influence of different rolling conditions on the plastic instability of the composite plate after rolling,and compare with the results of finite element simulation,so as to verify the correctness of the analysis in the previous chapter.Due to the experimental conditions and material limitations,the influence of different rolling conditions on the plastic instability of aluminum/steel/aluminum three-layer symmetric composite plate after rolling is only compared with the influence of the thickness ratio and the reduction rate.Finally,through comparison,the experimental results are consistent with the results of finite element simulation,thus confirme the influence of different rolling conditions obtained by finite element analysis on the plastic instability of composite plate after rolling.