Combined loadings after medium velocity impact on large CFRP laminated plates: Discrete ply model simulations

Abstract

To decrease development costs of aeronautical composite structures, industrials and academic researchers are turning to “virtual testing” methods. To help achieve this objective, a new methodology has been developed at the Institut Clément Ader. It is based on a complex loading test rig for technological specimens (more representative than the usual level of coupons) and the Discrete Ply Model (DPM), a model allowing the main damage occurring in composite structures to be simulated. This research focuses on the combined loading of CFRP plates after impact. In a previous work, plates were experimentally impacted and loaded after the impact in the VERTEX test rig and a methodology to transfer boundary conditions to the numerical model was validated using a simple model without damage. In the work presented here, the DPM was used to simulate both the impact and the complex loading after impact tests. Numerical results and experimental results showed satisfactory correlation. The research undertaken demonstrates that the impact damage has very little influence when the tests are performed at larger scales than coupons. It is therefore paramount to use a pyramidal approach to design and test composite structures, in order to avoid oversizing.

Keywords

• Composite structures
• Structural testing
• Medium velocity impact
• Combined loading
• Numerical modeling