Deformation Contour Analysis in Elastic Plastic Fatigue Fissure using Local and Global Integral Approach

Abstract

This paper present mathematical modelof local and global integral for elastic plastic damage mechanism of displacement discontinuity. The discrete nature of stress intensity factor approach where there is large scale yielding is inadmissible; hence, continuous energy path contour analysis becomes crucial. The simple energetic path can easily be evaluated computationally and the most prevalent method. However, fails to account for dynamic effect, kinetic energy and thermal effect, body force and effect of surface traction. The research is focused on deformation contour analysis of elastic-plastic void growth. In this paper, local and global representation of deformation field near a crack tip due to loading was examined using Divergence theorem and energy balanced method. The local integral is equivalent to energy release rate for nonlinear elastic materialunder quasi-static condition. The global J- Integral captured thermal effect, body force non zero surface traction and effect of plasticity. The integral permits more accurate analysis possible for all deformation fields including very close proximity of crack tip and all categories of material.TheFatigue crack growth analysis was developed to support economic fail safe and damage tolerance philosophies, and the execution, effectuation of damage tolerance control procedures for the workings of structural systems.