The Effect of Wedge Tip Angles on Stress Intensity Factors in the Contact Problem between Tilted Wedge and a Half Plane with an Edge Crack Using Digital Image Correlation

TL;DR

This study uses Digital Image Correlation to measure stress intensity factors in a contact problem involving a tilted wedge and a cracked half-plane, revealing how wedge tip angles influence stress distribution.

Contribution

It introduces an experimental approach combining DIC and image correlation to evaluate stress intensity factors and their dependence on wedge tip angles in contact mechanics.

Findings

DIC provides accurate SIF measurements consistent with photoelasticity.

Wedge tip angles significantly affect stress intensity factors.

Correlation coefficient method improves displacement measurement reliability.

Abstract

The first and second mode stress intensity factors (SIFs) of a contact problem between a half-plane with an edge crack and an asymmetric tilted wedge were obtained using experimental method of Digital Image Correlation (DIC). In this technique, displacement and strain fields can be measured using two digital images of the same sample at different stages of loading. However, several images were taken consequently in each stage of this experiment to avoid the noise effect. A pair of images of each stage was compared to each other. Then, the correlation coefficients between them were studied using a computer code. The pairs with the correlation coefficient higher than 0.8 were selected as the acceptable match for displacement measurements near the crack tip. Subsequently, the SIFs of specimens were calculated using displacement fields obtained from DIC method. The effect of wedge tips angle on their SIFs was also studied. Moreover, the results of DIC method were compared with the results of photoelasticity method and a close agreement between them was observed.