Thermomechanical behaviour of a glass/epoxy composite plate under local laser irradiation is investigated. Physico-chemical transformations and gas transport in a matrix and fibers are describe by Arrhenius and Darcy's law. The changes of material thermal properties are expressed in terms of the volume fractions of fiber, resin, gas and char. At the same time, we take into account the effects of pore pressure and elevating temperature on thermal stresses and strains. It is established that transverse stress, radius stress and interlayer shear caused by local heating and pore pressure are causes of delamination and cracking of composite plates under laser heating. And interlayer shear can lead failure of composite fast.
In order to simulate the interaction between high power laser and carbon fiber polymer composites, a 1D finite element model has been developed to research the decomposition process of composite pyrolysis. Mass and energy balance equations and gas convection have been solved in the model. The results of the computer simulation show a narrow reaction region formed in the composite with a huge pore pressure.