Accurate and efficient method for analyzing mixed-mode SIFs for inclined surface cracks in semi-infinite bodies by using numerical influence function method

摘要

An effective technique to compute mixed-mode stress intensity factors (MM-SIFs) for inclined surface cracks in semi-infinite bodies under arbitrary stress fields is proposed and validated. The proposed technique in this study is accurate and handiness for calculating MM-SIFs of different crack angles by using only one non-inclined cracked model. The benefit of this technique is achieved by using the influence function method (IFM) to evaluate MM-SIFs. A fully-automated influence coefficient database (ICDB) calculation system is developed based on the IFM. The interaction integral method (IIM) including the crack face traction (CFT) integral, which can improve the accuracy of SIF solutions, is employed in the developed ICDB. Once the ICDB for unit distributed load (UDL) is established for a target finite element (FE) model, MM-SIFs under arbitrary stress distributions of different crack angles can be calculated accurately in a short time. The developed ICDB is validated by comparing mode-I and MM-SIF solutions obtained by IFM with well-established reference solutions for different crack angles and Poisson's ratios. The effect of Poisson's ratio on MM-SIFs is also discussed based on the SIF solutions.