Closed-form Solutions for Predicting Interlaminar Shear Stress and Hygrothermomechanical Normal Stress in Composite Beams with Rectangular and Tubular Cross-sections

Closed-form analytical solutions for thin-walled laminated composite beams with tubular and rectangular cross-sections are developed for evaluating interlaminar shear stress and thermally induced stresses. The formulations are fundamentally based on modified Composite lamination theory and parallel axis theorem. The present approach includes a variation of ply stiffness along the contour of the cross-section. Interlaminar shear stresses in cantilevered composite beams with rectangular cross-section under a transverse load is analytically determined to be independent of a temperature differential subjected to uniform temperature environment. An ANSYS based threedimensional finite element model for computing thermal stresses of both cross-sections is further demonstrated. The results obtained from analytical solutions give an excellent agreement to finite element results. This mathematical model represents an efficient tool for structural design engineers to perform parametric studies during the preliminary design phase.