A Delamination in a Three Layers Laminated Beam Subjected to Thermal Gradient

Abstract

A laminated beam containing an initial delamination subjected to thermal gradient is analyzed on the basis of classical beam theory. The axial forces are induced in the parts of the constituent beams above and below the delamination. For the case where crack faces are open, a nonlinear equation for determining the in-plane forces is derived by modeling the delaminated part as two lapped beams hinged at both ends, and by imposing the compatibility condition of the deformations of the two beams. Numerical solutions are obtained for some model beams. It is shown that the relative displacement at the center of the delamination increases gradually with the increase very rapidly, i.e., local delamination buckling occurs. Energy release rate is small for temperature gradient below the critical value, but it takes a large value when the temperature gradient is increased beyond the critical value.