1. Evaluation of the Puck Failure Theory for Fiber Reinforced Composites Student Name 20 April 2009 ME7501

2. Introduction Failure Theories Compressive Transverse Stress Shear Stress

3. Objective Evaluate the relative performance of Puck’s Failure theory with more traditional theories Consider udfrc subjected to Transverse and Shear Loading

4. Failure Theories Limit – Max Stress/Strain Interaction – Tsai-Wu – Hill-Tsai Separate Mode – Hashin-Rotem – Puck

5. Puck Failure Theory Separate Mode Based on Coulomb-Mohr theory for the failure of brittle materials – ‘The stresses on the fracture plane are decisive for fracture’ -Otto Mohr 2 modes of failure – Fiber – Inter-Fiber Location of fracture

6. Puck Failure Theory: Inter-Fiber Failure

8. Puck Failure Theory: Master Fracture Body

9. Puck Failure Theory: AS4/55A

13. Conclusions Good performance leading up to and immediately after maximum shear stress point Good transitional performance between tensile and compressive transverse stress Poor performance near maximum compressive stress Requires test data for optimal performance

14. References Sun, C.T., Quinn, B.J., Tao, J., and Oplinger, D.W., “Comparative Evaluation of Failure Analysis Methods for Composite Laminates”, DOT/FAA/AR-95/109, May 1996. Puck, A. and Schürmann, H., “Failure analysis of FRP laminates by means of physically based phenomenological models”, Comp. Sci. and Techn. 58 (1998) 1045-1067. Lutz, G., “Fibrous Composite Failure Criteria - Fact and Fantasy.” CDCM 2006 - Conference on Damage in Composite Materials 2006, Stuttgart, Germany, September 18-19, 2006.

15. Back-up Slides