The instability behaviour of laminated panels with elastically rotationally restrained edges

The analytical approach based on a semi-energy method was developed to study the instability behaviour of symmetrically laminated carbon fiber reinforced plastic panels in pure compression. A four-term polynomial function is used to postulate the out-of-plane deflection form of a laminated panel. A one-term post-buckling function is used in conjunction with the semi-energy method of analysis. The von Karman type large deflection compatibility equation governing the behaviour of laminated panels is used together with a consideration of the total strain energy of the system. From the large deflection compatibility equation, the deflection function is related to the stress function in terms of the unknown coefficients in the assumed deflection function. These are then substituted in the total strain energy expressions and the theorem of minimum total potential energy is applied to solve for the unknown coefficients.