Revised wide range compliance solutions for selected standard and non-standard fracture test specimens based on crack mouth opening displacement

Abstract

This work addresses the development of wide range compliance solutions for tensile-loaded and bend specimens based on CMOD. The study covers selected standard and non-standard fracture test specimens, including the compact tension C(T) configuration, the single edge notch tension SE(T) specimen with fixed-grip loading (clamped ends) and the single edge notch bend SE(B) geometry with varying specimen span over width ratio and loaded under 3-point and 4-point flexural configuration. Very detailed elastic finite element analysis in 2-D setting are conducted on fracture models with varying crack sizes to generate the evolution of load with displacement for those configurations from which the dependence of specimen compliance on crack length, specimen geometry and loading mode is determined. To examine 3-D effects, including the influence of side-grooves, on the specimen compliance response, numerical analyses are also performed on 3-D models of selected plane-sided and side-grooved fracture specimens. The extensive numerical analyses conducted here provide a large set of compliance solutions, which not only validate the compliance relationships available in existing standards, but also help consolidating elastic compliance functions of common specimen geometries for use in routine test procedures for experimental evaluations of crack size changes in fracture toughness and fatigue crack growth testing.