Global stiffness determination of a cross-ply laminated composite plate with distributed delaminations and matrix cracks and its application

This paper is focused on a global stiffness method for cross-ply laminated composite plates with distributed delaminations and matrix cracks that makes it possible to find its solution by simply replacing stiffness quantities in the known solution for the undamaged counterpart. Local and zero stiffness model are introduced to determine the local stiffness in damaged regions and using the energy functional expression based on the first-order shear deformation theory (FSDT) and the classic laminate theory (CLT), the global stiffness is analytically determined by combining stiffness terms in undamaged and damaged regions with corresponding area ratio weights. The obtained global stiffness is used to analyse bending and buckling problem of a simply supported plate with distributed delaminations and matrix cracks subjected to in-plane and transverse loads, being validated through ANSYS simulation.