Study on the Constitutive Model of Vibratory Plastic Forming for Metal Materials

Abstract

Vibratory plastic forming process is a plastic forming technology to form by imposing a vibration like ultrasonic wave on both die and workpiece, which could improve the deformability and forming quality of the workpiece. There is obvious decrease on the stress-strain curves of the metal materials under vibration condition than normal condition. The constitutive relationships of them under vibration condition differ from these under static tensile test. In this paper, a constitutive equation model of elastic viscoplasticity is given. Under the condition of one-dimensional stress the analytical solution of the dynamic stress in certain control strain condition is also given. An experimental system for mechanical behavior test for metal materials under vibration condition is established. Through it, the uniaxial tensile tests on low carbon steel and brass is done. The test result is mainly same as the theoretical calculation value. It verifies the validity of elastic viscoplasticity model.