Simulation of Low Velocity Impact on Composite Plates with Compressive Preload

The impact behaviour of fibre-reinforced composite materials is much more complex than it is for conventional metallic structures due to a number of different failure modes on the interlaminar and intralaminar level. In most of the past research studies unloaded specimens have been used for impact tests. However, in reality it is much more likely that a composite structure is exposed to a certain stress state when it is being impacted, which can have a significant effect on the impact performance. Therefore, in this study the influence of a compressive preload on the low velocity impact behaviour of a carbon fibre-reinforced composite plate was investigated both experimentally and numerically. Besides the evaluation of the experimental findings, this paper primarily describes the finite element modelling strategy of this preloaded composite plate for impact simulations with LS-DYNA. The main topics addressed in this context are the composite material and delamination modelling as well as the implementation of the preload. The assessment of different modelling approaches, the influence of various simulation parameters and a comparison of the experimental and numerical results are documented in this paper.