Modelling low-speed drop-weight impact on composite laminates

• Understand composite delamination behaviours in different impaction conditions.
• Damage resistance highly depend on design of fibre orientation and layup sequence.
• Clustered plies in laminate can effectively reduce the degree of interface damage.
• Indenter geometries and plate shapes design significantly affect impact behaviour.
• Suggestions are proposed for designing impact tests for particular purposes.

The impact responses of typical laminates are investigated numerically in this research. Delamination responses among plies and fibre and/or matrix damage responses within plies are simulated to understand the behaviours of laminates under different impaction conditions. Damage resistance of a laminate is highly dependent upon several factors including geometry, thickness, stiffness, mass, and impact energies (impact velocities), which are here considered by the finite element (FE) method. Three groups of composite laminates are simulated and the numerical results in general are in good agreement with corresponding experiments. Models containing different stacking sequences and impact energies are built to study their influence on impact responses and demonstrate that clustered (or nearly clustered) plies in the laminate can effectively reduce the degree of interface damage. Models containing different indenters and plate shapes are also built to systematically study their influence on the low-speed drop-weight behaviour of composite laminates. Suggestions are proposed for designing impact tests for particular purposes.