ANALYSIS OF LAMINATED COMPOSITE SKEW SHELLS USING HIGHER ORDER SHEAR DEFORMATION THEORY

Abstract

STATIC ANALYSIS OF SKEW COMPOSITE SHELLS IS PRESENTED BY DEVELOPING A C₀ FINITE ELEMENT (FE) MODEL BASED ON HIGHER ORDER SHEAR DEFORMATION THEORY (HSDT). IN THIS THEORY THE TRANSVERSE SHEAR STRESSES ARE TAKEN AS ZERO AT THE SHELL TOP AND BOTTOM. A REALISTIC PARABOLIC VARIATION OF TRANSVERSE SHEAR STRAINS THROUGH THE SHELL THICKNESS IS ASSUMED AND THE USE OF SHEAR CORRECTION FACTOR IS AVOIDED. SANDER’S APPROXIMATIONS ARE CONSIDERED TO INCLUDE THE EFFECT OF THREE CURVATURE TERMS IN THE STRAIN COMPONENTS OF COMPOSITE SHELLS. THE C₀ FINITE ELEMENT FORMULATION HAS BEEN DONE QUITE EFFICIENTLY TO OVERCOME THE PROBLEM OF C₁ CONTINUITY ASSOCIATED WITH THE HSDT. THE ISOPARAMETRIC FE USED IN THE PRESENT MODEL CONSISTS OF NINE NODES WITH SEVEN NODAL UNKNOWNS PER NODE. SINCE THERE IS NO RESULT AVAILABLE IN THE LITERATURE ON THE PROBLEM OF SKEW COMPOSITE SHELL BASED ON HSDT, PRESENT RESULTS ARE VALIDATED WITH FEW RESULTS AVAILABLE ON COMPOSITE PLATES/SHELLS. MANY NEW RESULTS ARE PRESENTED ON THE STATIC RESPONSE OF LAMINATED COMPOSITE SKEW SHELLS CONSIDERING DIFFERENT GEOMETRY, BOUNDARY CONDITIONS, PLY ORIENTATION, LOADINGS AND SKEW ANGLES. SHELL FORMS CONSIDERED IN THIS STUDY INCLUDE SPHERICAL, CONICAL, CYLINDRICAL AND HYPAR SHELLS.