Applications of the Extremal Principles of Elasticity to the Determination of Stress Intensity Factors.

摘要

A method for determining Stress Intensity Factors in edge cracked elastic sheets subjected to arbitrary in-plane loadings is presented. The method employs an eigen-function expansion,with the coefficients chosen through the Energy Principles of Elastostatics. Two-dimensional plane problems with prescribed boundary tractions,prescribed boundary displacement,and mixed problems are considered. Examples given include plates of finite length with edge cracks and plates with cracks originating from the tip of edge notches. Results are given for stress intensity factors in rectangular tensile sheets of various aspect ratios,and for rectangular sheets with prescribed uniform end displacements. Calibration curves for the Fatigue Crack Life Gauge are developed,and some implications for gauge design are noted. (Author)