Geometry and load fixture effects in the four-point-bend mixed mode fracture specimen

Abstract

This paper presents a numerical study of specimen geometry and load frame/specimen interaction of a four-point-bend mixed mode fracture specimen. The aspect ratio of the specimen, the stick/slip condition between the loading pin and specimen, and the lateral and rotational restraint of the load train all have a potentially significant effect on the mode I and mode II crack tip fields in the specimen. These effects are illustrated by the dependence of the uncracked stress fields, mode I and mode II stress intensity factors, and crack opening and sliding displacements on geometric parameters and load train restraint conditions.