Numerical and experimental study of multimode failure phenomena in GFRP laminates of different lay-ups

ABSTRACT

Induced delamination due to low velocity impact results in degradation of load-carrying capacity of composite structures especially when loading is predominantly in compression. In this paper, size, shape and orientation of delamination that occur due to low velocity impact is obtained by numerical modelling and results are validated through experiments. Initially, numerical model is validated for single-mode fracture tests like double cantilever beam and end-notch flexure. Multimode failure phenomenon like low velocity impact was also simulated for different lay-ups such as cross-ply, angle-ply and quasi-isotropic and validated through experiments. Low velocity impact testing of laminates was done using drop weight impactor, and experimentally obtained force–time and energy–time history were compared with numerical results. Good match is obtained between simulations and experiments. Delamination size was also compared and it is found that numerical model correctly predicts the size, shape and orientation of delamination for all lay-ups.

KEYWORDS:

• Delamination
• fracture
• low velocity impact
• numerical modelling

Acknowledgment

The author wish to acknowledge the support and contribution made by members of Composite Research Center, more specifically Irfan Khan for testing and Vinod Duraiswamy and his team in fabrication of RFI samples.