ANALYSIS OF THICK SKEW LAMINATE WITH ELLIPTICAL CUTOUT SUBJECTED TO NON-LINEAR TEMPERATURE DISTRIBUTION: MAJOR AXIS OF ELLIPSE COLLINEAR WITH SHORTER DIAGONAL

MSR Niranjan Kumar (India), Mmm Sarcar (India), V. Bala Krishna Murthy (India) and K. Mohana Rao (India)

Received January 10, 2008

Abstract

Materials are put to serious test when they are subjected to elevated temperatures. Estimation of thermal stresses and deformations of fibre reinforced composite plates is more complex owing to material anisotropy. Hence an effort is made to study the thermo elastic behaviour of a cross-ply laminated composite skew plate with elliptical cutout subjected to non-linearly varying temperature loading has been investigated in the present analysis. Major axis of the ellipse collinear with the shorter diagonal has been taken for the present analysis. A three-dimensional heat conduction analysis in fibre reinforced composite laminates has been simulated by finite element method to get realistic temperature in the laminate under different thermal boundary conditions. A finite element method, which works on the basis of three-dimensional theory of elasticity, is employed to evaluate the stresses and deformations. The results obtained by varying the skew angle and size of the cutout are discussed. The magnitude of the major in-plane stress due to temperature loading is greatly affected by the skew angle variation and its magnitude is observed to be minimum at higher value of the skew angle. The magnitudes of inter laminar stresses are observed to be minimum at lower ratio. The transverse deflection ‘w’ decreases with increase in skew angle.

Keywords and phrases: FEM, skew laminate, cutout, interlaminar stresses.