Modeling damage evolution of composite laminates under low velocity off-center impact

In the current study, low velocity off-center impacts of glass/epoxy laminates considering different impact locations are investigated experimentally and numerically. Low velocity impact tests are performed using an instrumented drop-weight machine and the composite specimens are formed through the use of the vacuum infusion process. To simulate low velocity impact properties of the composite, the finite element software ABAQUS/Explicit is employed. The damage model is implemented in the FE code by a user-defined material subroutine (VUMAT). In order to effectively describe the progressively intralaminar damage for composite laminates, two three-dimensional progressive damage models are presented exponentially and linearly and for predicting damage initiation of composite plates, 3D Hashin’s failure criterion is chosen. Both damage models are established as functions of energy dissipated by damage in addition to introducing the characteristic length for each three dimensional solid element. The contact force-time histories and peak loads are obtained to compare the numerical and the experimental results at several impact energy levels and three different impact locations of the composite plates. In addition to these achievements, the comparison of the numerically predicted damage pattern and damage size and those observed experimentally can verify the efficiency of the present models