Papers by Keyword: Degradation Rule

Abstract: The finite element software was used to get the X-cor sandwich’s shear strength. During the shear strength analysis, the failure criterion and materials stiffness degradation rules fitting for the analysis of X-cor sandwich’s failure mechanism were proposed and the X-cor sandwich’s failure process and modes were also clarified. According to the failure criterion we used the elements with stiffness degradation and their distributions in the finite element model to simulate the types and propagation path of the failure and the failure mechanisms of X-cor sandwich under shear were explained. The finite element analysis indicates during the shear firstly the resin regions fail and then the multiple failure modes of Z-pin pull-out from the face-sheet, Z-pin shear off and Z-pin buckling all exist. The propagation paths of the failure elements are dispersive. By contrasting the finite element results and test results the values are consistent well and the error range is -10.4%~7.4%. The comparison results show that the failure criterion and stiffness degradation rules are reasonable and this method can be used to predict the X-cor sandwich’s shear strength.

Abstract: In this article the finite element software was used to analyse the values for compressive strength of X-cor sandwich. During the analysis, the failure criteria and materials stiffness degradation rules of failure mechanisms were proposed. The failure processes and failure modes were also clarified. In the finite element model we used the distributions of failure elements to simulate the failure processes. Meanwhile the failure mechanisms of X-cor sandwich were explained. The finite element analysis indicates that the resin regions of Z-pin tips fail firstly and the Z-pins fail secondly. The dominant failure mode is the Z-pin elastic buckling and the propagation paths of failure elements are dispersive. Through contrast the finite element values and test results are consistent well and the error range is -7.6%~9.5%. Therefore the failure criteria and stiffness degradation rules are reasonable and the model can be used to predict the compressive strength of X-cor sandwich.