Entwicklung einer Kommunikationsroutine zur Abbildung matrixrissinduzierter Delaminationen in der mesoskaligen progressiven Schädigungsanalyse von Faserverbundstrukturen

Abstract

In general, delaminations represent a significant and in most cases catastrophic failure preceding form of damage in fiber reinforced structures. One of the main causes of delamination is intralaminar failure in form of matrix cracks. In this case, a redistribution of stresses across the matrix crack leads to an increase of the stresses in the adjacent interlaminar boundary layer. As consequence the chances of delaminations increase. Until recently the representation of such delaminations was based on the insertion of crack depicting elements into the matrix crack prone layers of the laminate and the interlaminar boundary layer. Since this requires the prognosis of the position of the matrix cracks, a communication routine is implemented. This routine ensures that in the case of intalaminar failure, as indicated by a non-discrete material model, the material model of the interlaminar boundary layer is informed. For the implementation of this routine a pre-processing program is created that extracts information about neighbouring elements from the geometry data. The combination of both material models is expanded by an additional subroutine, that handles the exchange of information between the material models and enables the sychronisation of the processsors for the parallelisation of the calculation. Additionally, both the material model of the laminate layers and the boundary layer are changed, in a way that the material model of the laminate layers saves information about matrix failure in an array and that the material model of the boundary layer uses that information to initiate delamination. For the purpose of testing the communication routine, a 4-point-bending experiment is modelled, where experimental and numerical analysis have already been performed. The results show that on a technical level the routine is working as intended. However, a development of the delamination beyond the prescribed damage, that is clearly retraceable to the matrix cracks is only visible with a very fine mesh. Furthermore, different material and simulation parameters are investigated.