Engineering Commons^™

Mechanistic Failure Criterion For Unidirectional And Random Fibre Polymer Composites, Jamaloddin Jamali

Electronic Thesis and Dissertation Repository

Polymer composite design in energy absorbing components requires a failure criterion that can predict the energy involved in its fracture under different modes of loading. Present mixed mode criteria are mainly empirical or semi-empirical, and are only suitable for a small range of composite types.

The purpose of this study was to develop a mechanistic failure criterion that is applicable to a wide range of polymer composites. An energy based mechanistic failure criterion is proposed to characterize the toughness of unidirectional (UD) and randomly oriented short fibre composites (random fibre composites).

In UD and random composites, the criterion predicts the …

Mechanistic Mixed-Mode Failure Criterion For Continuous Fiber-Polymer Composites, Thomas P. Bruce

Electronic Thesis and Dissertation Repository

Design of continuous fiber-polymer composite components with optimized and predictable energy dissipation requires a failure criterion able to predict the fracture energy of CFP composites for all mixed-mode loading conditions. Existing mixed-mode failure criteria are empirical and show poor correlation for a range of CFP composites. Therefore, a universally applicable criterion based on constituent material properties and operative failure mechanisms is required. A novel mechanistic failure criterion for CFP composites is proposed. The criterion considers resin fracture strength, hackle formation, interfacial debonding, the crack tip plastic zone and interply vs interyarn delamination. Experimental data obtained by mixed-mode testing of continuous …