Application of Whitney and Nuismer stress fracture criterion to compositesloaded in shear

Acknowledgement of the current lack of research conducted upon assessing th e damage tolerance of a composite loaded in inplane shear and predictions o n residual strengths for this loading condition has provoked attempts to re ctify this apparent void in composite research. A literature survey in this field has identified three key issues for this apparent deficit: lack of a suitable test method; difficulty in achieving pure sheer, and non-existenc e of a suitable failure criterion. Through a combination of mechanical testing and stress analysis, using fini te element analysis, an existing shear test method has been modified for th e specific use of evaluating the damage tolerance of composites loaded in i nplane shear. To predict the residual strength of a composite loaded in inp lane shear, an existing stress failure criterion, originally developed for uniaxially loaded composites with notches or cracks was adapted for this lo ading condition. Both the adapted test method and the modified stress failu re criterion proved to be suitable for this task. PRC/1548 (C) 1999 IoM Com munications Ltd.