Mechanical and numerical modeling of the cracks closure/opening effects in laminates

This paper presents a unilateral damage model coupled with an orthotropic elastic behaviour, to analyse the cracks closure/opening effect on the behaviour of a plate made of long fibre reinforced polymer matrix. The cracks are supposed to grow along the fibres direction with different opening ways. According to the sign of the stress normal to the fibres direction (in the plate plane), the cracks are supposed to be open or closed. When the cracks are closed, the lips of the cracks can slide or stick according to the respective value of the shear and normal stresses. At that moment, the virgin behaviour is recovered in compression. The shear behaviour is either damaged or virgin according to the state of the cracks (sliding or sticking). A numerical implementation has been made considering a representative elementary cell of laminate and some results are presented to show the model ability to report the different situations.