Based On The Hybrid Stress Finite Element Of The Global-the Local Method And Damage Laminate Residual Strength Study

In this dissertation, a global-local approach using hybrid stress element and its application in the stress distribution and the residual strength of composite laminate weakened by damage are studied in detail. Based on the laminate theory, a laminate weakened by damage is treated as an anisotropic thin plate. Using the complex potential method in the plane theory of elasticity of an anisotropic body, the series solution of finite anisotropic thin plate containing an elliptical inclusion is proposed with the help of Faber series. A hybrid element with an elliptical inclusion for anisotropic materials is obtained by using the hybrid variable principle, and the element efficiency is verified by numerical examples. The state of the damage is modeled by an elliptical soft inclusion, and using the point stress criterion based on characteristic curve and Yamada-Sun etc. criteria, the prediction of the strength of a composite laminate with damage is set up. The effects of various parameters on the stress distribution and the residual strength of a composite laminate weakened by damage are detailedly studied. Several conclusions valuable to practice are drawn.