Delamination analysis of a multilayered beam structure under bending at a constant velocity

Delamination cracks are detected often in multilayered beam structures during lifetime. This fact raises concerns about serviceability of multilayered structures. Apparently, there is a need for tools to adequately predict whether further functioning of these structures is safe. Developing of such tool is subject of this work. In particular, the work is concerned with the problem of delamination analysis of a multilayered beam structure subjected to bending at a constant velocity (the angle of rotation of the free end of the lower arm of the delamination crack varies with time at a constant velocity). The layers of the beam are made of non-linear elastic structural materials that exhibit smooth inhomogeneity along the thickness. Therefore, the material parameters of the non-linear constitutive law are continuous function of the transversal coordinate, z. The method of the integral J is used for analyzing the delamination behavior of the beam. The analysis takes into account the bending velocity. A check-up of the analysis is performed by deriving the strain energy release rate (SERR). The analysis is applied for determining the safe velocity of the angle of rotation. The safe delaminaton length and the time of safe functioning of the beam structure are determined too. The effect of additional support introduced in the beam on the time of safe functioning is also evaluated.