EXPERIMENTAL AND FINITE-ELEMENT PREDICTIONS OF RESIDUAL-STRESSES DUE TO ORTHOGONAL METAL-CUTTING

The development and implementation of a finite element method for the simulation of plane-strain orthogonal metal cutting processes with con tinuous chip formation are presented. Experimental procedures for orth ogonal metal cutting and measurement of distributions of residual stre sses using the X-ray diffraction method are also presented. A four-nod e, eight degree-of-freedom, quadrilateral plane-strain finite element is formulated. The effects of elasticity, viscoplasticity, temperature , friction, strain-rate and large strain are included in this formulat ion. Some special techniques for the finite element simulation of meta l cutting processes, such as element separation and mesh rezoning, are used to enhance the computational accuracy and efficiency. The orthog onal metal cutting experiment is set-up on a shaper, and the distribut ions of residual stresses of the annealed 1020 carbon steel sample are measured using the X-ray diffraction method. Under nominally the same cutting conditions as the experiment, the cutting processes are also simulated using the finite element method. Comparisons of the experime ntal and finite element results for the distributions of residual stre sses indicate a fairly reasonable level of agreement. The versatility of the present finite element simulation method allows for displaying detailed results and knowledge generated by orthogonal metal cutting p rocesses, such as the distribution of temperature, yield stress, effec tive stress, plastic strain, plastic strain-rate, hydrostatic stress, deformed configuration, etc. Such knowledge is useful to provide physi cal insights into the process as well as to better design the process for machining parts with improved performance.