Continuous Tension/Compression Experimental Device Of Sheet Metals And The Springback Simulation

With the development of theory and technology,the Finite Element Method and CAE software have been widely used in the design and analysis of automobile and other fields,which greatly promotes the research and development progress and saves a lot of resources for enterprises and researchers.However,in order to improve the accuracy of finite element simulation,it is necessary to correctly understand and define the relevant properties of the material,in which the Bauschinger effect of the aluminum alloy,high strength steel and other plates under the complex loading path is vital for accurate stamping simulation especially for rebound prediction.To study the Bauschinger effect of the plate,the unidirectional continuous tensile and compression experiment of the plate is the most ideal experimental method,but it is very easy to occur instability of the plate when the plate was subjected to compression load in experiment,which makes the research process of constitutive model relatively slow.In view of above situation,this paper carried out a large number of experiments,designed and fabricated relevant experimental devices,also obtained the parameters of the related materials through finite element method.The main research results were as follows:(1)Considering the difficulty of continuous tensile and compression of sheet metals,this paper designed a new set of test device for tension and compression without expensive additional equipment,with simple structure.This test device,which effectively overcomes the buckling instability of plate during compression,is easy to loading and operate,making the continuous tensile compression experiment proceed smoothly.(2)In this paper,low-carbon steel Q235,aluminium alloy AL6061 and high-strength steel DP780 were tested.According to the relevant national standards and the existing literature,uniaxial tensile specimens and continuous tension-compression specimens were designed,and the relevant experiments were carried out.Therefore the uniaxial tensile data and the continuous cycle tension-compression data have been obtained,which provided necessary experimental data for the following work.(3)Based on the above work,the finite element model of continuous tension and compression cycle experiment was constructed through the finite element software Abaqus.By selecting different hardening models,constantly adjusting the input parameters and optimizing the simulation curve,the Bauschinger effect was effectively simulated,and the optimal parameters which reflect the hardening law of material were obtained,which provide effective data for improving the accuracy of finite element simulation.(4)In order to verify the prediction ability of different hardening models for stamping springback,the U-shaped stamping experiment and the simulation was carried out.By comparing experimental data with simulation data,it is proved that the combined model can predict the springback more accurately,and it shows that the continuous tension and compression experimental device designed in this paper is effective and has high application value.