Experimental and analytical evaluation of mixed mode fracture in graded multifunctional materials

Document Type

Conference Proceeding

Date of Original Version



A comprehensive experimental and analytical study is presented investigating the phenomena of dynamic fracture in graded multifunctional materials. First, an elastodynamic solution for a crack propagating at an angle from the direction of property variation in an FGM is developed. Subsequently, a series of experiments were performed to study the crack propagation in these materials. Dynamic photoelastic studies coupled with high-speed photography were performed to obtain full-field stress data for a propagating crack in an FGM. Due to the opaqueness of the FGMs birefringent coatings were used to capture the isochromatics associated with the moving crack. The dynamic stress field developed in this study was utilized to analyze the photoelastic fringes and to obtain fracture parameters. Dynamic fracture experiments were performed with different specimen geometries to develop a ȧ (crack velocity) - K ID (dynamic stress intensity factor) relationship for FGMs. A similar ȧ - K ID relation is also developed for matrix material (polyester) for comparison purposes. The results obtained show that the behavior of a crack growing in FGMs is different from homogeneous materials. The crack propagation velocities in FGMs are found to be 60% higher than polyester. Crack arrest toughness is found to be 8 % lower than the value of local fracture toughness in FGMs.

Publication Title

Proceedings of the 2005 SEM Annual Conference and Exposition on Experimental and Applied Mechanics

This document is currently not available here.