Dynamic impact onto laminated composite structures can lead to large-scale delamination. This can be mitigated by the introduction of through-thickness reinforcement, such as z-pins. Here, mode I & II and mixed-mode delamination tests have been designed and conducted at high loading rate, for both unpinned and Z-pinned coupons to study the effect of rate of loading. It was found that the Z-pins were not effective in delaying the dynamic crack initiation or resisting the dynamic propagation of delaminations shorter than 5 mm. However, the further growth of cracks was substantially delayed by Z-pinning, especially for the pure mode I and mode I dominated failure modes. On the other hand, the effectiveness of Z-pins in shear tests was relatively modest. The mode I dominated delamination resistance of Z-pinned laminates was found to be sensitive to the loading rate.
|Number of pages||12|
|Journal||Composites Part A: Applied Science and Manufacturing|
|Early online date||1 Aug 2019|
|Publication status||Published - 1 Oct 2019|
- Fracture mechanics
- Through-thickness reinforcement
Cui, H., Mahadik, Y., Hallett, S. R., Partridge, I. K., Allegri, G., Ponnusamic, S. A., & Petrinic, N. (2019). Coupon scale Z-pinned IM7/8552 delamination tests under dynamic loading. Composites Part A: Applied Science and Manufacturing, 125, . https://doi.org/10.1016/j.compositesa.2019.105565