A QUASI-STEADY-STATE THERMO-ELASTO-PLASTIC ANALYSIS OF STRESS DISTRIBUTION IN THE WORKPIECE IN MACHINING
Abstract
An elasto-plastic finite element program has been modified and extended to include thermal effect for investigating: (1) the effect of shear plane boundary condition on the stress field in the workpiece in orthogonal machining, (2) the effect of the degree of constraint (plane strain and plane stress) on the stress field in the workpiece in machining and (3) the effect of the thermal loading on the stress field in the workpiece in orthogonal machining. The balances of force and moment on both the shear plane and tool rake face are used to calculate the boundary condition, i.e., normal stress distribution on the shear plane. The primary plastic deformation and the stress field in the workpiece under mechanical loading for plane strain condition and plane stress condition are investigated. The temperature distributions obtained following Stevenson's procedure are used as the thermal loading. The results of finite element analysis show that the type of the normal stress distribution on the shear plane does not significantly affect the value of the stress in the workpiece. The length of the shear plane is found to be a major parameter governing the stress field in the workpiece in machining, confirming a previous experimental study by Liu and Barash. Plane stress condition produces lower stress field in the machined workpiece. Thermal loading does not significantly affect the stress value in the workpiece, while mechanical loading is proved to dominate the stress field in the workpiece in machining.
Degree
Ph.D.
Subject Area
Industrial engineering
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.