In this article the failure of rectangular composite plates is studied under torsional loads using multiple failure theories. Lekhnitskii's equations for calculating the stress distribution under torsion are compared to test data and are shown to be unconservative in predicting failure stresses. However, the predicted torque to failure, based on finite element modeling, is within 6% of the actual tested values. The fact that for a state of pure shear (the axial stresses are negligible) the failure theories investigated in this paper reduce to the same equation, regardless of the failure theory, is disscussed.
Lekhnitskii, S.G. (1981). Theory of Elasticity of an Anisotropic Body, 283—288, Mir Publishers, USA.
2.
Gong, X., Lu, Gong, X.J., Laksimi, A. and Benzeggagh , M.L. (2000). Application of Tsai-Wu Criterion to Notched and Unnotched Composite Laminates under Torque Loading, Journal of Composite Materials, 34(6): 460—477.
3.
Sen, J.K. and Fish, J.C. (1996). Failure Prediction of Composite Laminates under Torsion, Key Engineering Materials, 121—122: 285—306.
4.
Yeh, H.-Y. and Kim, C.H. (1994). The Yeh-Stratton Criterion for Composite Materials, Journal ofComposite Materials, 28(10): 926—939.
5.
Rowlands, R.E. (1985). Strength Theories and Their Experimental Correlation , Chapter II, Handbook of Composites, Vol. III, Failure Mechanics of Composites, Sih, G. C. and Skudra, A. M. (eds), Elsevier Science Publishers, USA.
6.
Gong, X.L., Laksimi, A., Lai, D.W. and Benzeggagh, M.L. (1995). Stress Analysis in Unidirectional Composite Plates Under Torque Loadings: Experimental Observation, Journal of Reinforced Plastics and Composites, 14: 29—44.
