CALCULATION METHOD FOR DETERMINING TRANSVERSE SHEAR STIFFNESS COEFFICIENT OF CROSS-PLY LAMINATE

This paper presents two calculation methods for determining transverse shear stiffness coefficients,weight function method and strain energy method.The first method is similar to that proposed in Ref.〔1〕,with the exception of abandoning the assumption of parabolic distribution of transverse shear stress through thickness of the lamicate.Becaus the real distribution of shear stress is not exactly parabelie,especially for unsymmetrical laminates,the formula in Ref.〔1〕often yields inaccuracy. First of all,the formulas of transverse shear stress were derived.The least square method wa,s used to obtain the approximate weight functions for both symmetrical and unsytrimetrical laminates.Then.the shear stiffness coefficients were calculated by using the two methods. The results show that for the unsyrrirrtetrical laminat:the weight functiara method is better than the formula of Ref.〔1〕.As foe the comperison between the two methods of this paper,strain energy rnethod might be supcrior to the other one.