Buckling analysis of tri-layer beams with enveloped delaminations

By introducing new nondimensionalized axial and bending stiffnesses, a generalized analytical analysis using classical engineering solutions is proposed to study the buckling behavior of tri-layer beams having asymmetrical enveloped delaminations. Appropriate boundary and kinematical conditions are used to formulate the systematic homogeneous equations. The present analysis accurately predicts the buckling loads of tri-layer beams having double enveloped delaminations, which is verified with the previously published data for homogeneous beams having single and double delaminations. An excellent agreement between the results is observed. A transition region is observed as the normalized bending stiffness increases. Effective-slenderness ratio is defined and introduced, which gives a measure of local, mixed and global buckling phenomenon. The present analysis provides a useful reference for the tri-layer beams having enveloped delaminations.