Finite element modeling of sandwich composite structures subject to low velocity impact and delamination

摘要

Two common concerns in the use of sandwich composite construction are the effects of low velocity impact and delamination upon structural failure. Finite element analysis of these events can provide a comprehensive time history of the resulting stress strain, displacement, and velocity at all points in a structure. The purpose of this research is to develop a finite element model of a sandwich composite and use this model to analyze the dynamic response of an unbalanced sandwich beam, a balanced sandwich beam, and a balanced sandwich plate subject to low velocity impact. In particular, strain vs. time history, failure location and mode, and the influence of an existing delamination are investigated. It is found that, in the presence of a small delamination, the failure load of a sandwich composite structure increases. Also, failure in general is due to asymetric core shear and the location of this failure shifts to the delamination boundry in the case of a large delamination. Finally, it is noted that detecting the presence of a delamination using maximum displacement values may be difficult. (AN)