A new model to describe effect of plastic deformation on elastic modulus of aluminum alloy
(1.陕西省西安市西安交通大学机械工程学院
2.湖北省武汉市华中科技大学塑性成形模拟及模具技术国家重点实验室
3.School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
4.Xi’an Aeronautical Polytechnic Institute, Xi’an 710049, China
5.School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
2.湖北省武汉市华中科技大学塑性成形模拟及模具技术国家重点实验室
3.School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
4.Xi’an Aeronautical Polytechnic Institute, Xi’an 710049, China
5.School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
Abstract: In order to improve the prediction capability of spring-back in aluminum sheet metal forming, the influence of the plastic deformation on elastic modulus is considered when the material undergoes a large plastic deformation. The present work focused on establishing a new model to accurately describe the relation of elastic modulus and plastic deformation. The tensile tests were performed to investigate the influence of plastic deformation on elastic modulus at low strain rate. Two different aluminum sheets were used, AA2024-T3 and LY12-CZ, and the thickness of sheet metals was 1.3 mm and 2.0 mm, respectively. In order to overcome the drawback, which is directly measuring the slope of tension curve to obtain elastic modulus, an extrapolation method was adopted. The proposal macroscopic piecewise sinusoidal function can accurately model the elastic modulus variation.
Key words: plastic deformation; elastic modulus; aluminum alloy; spring-back