In this work, a comprehensive numerical study of the low-velocity impact (LVI) behavior of QUAD laminates vs. Double-Double (DD) stacking sequences has been performed. Finite element models were drawn, and analyses carried out in Abaqus/Explicit employing continuum shell elements (SC8R) for the plies, cohesive elements (COH3D8) for the delamination interfaces, and the built-in Hashin damage criterion for intralaminar failure. Two different impact energies (50 and 100 J) were applied using a hemispherical impactor mass of 6.25 kg, and the impact histories were investigated in force-time, displacement-time, and energy-absorption responses. The QUAD layup provided the stiffest response and highest peak contact forces, while it dissipated less energy, suggesting lower damage tolerance. Among the DD configurations, the variant designed for equal extensional stiffness (DI) had the lowest peak forces, the variant optimized with constraints on both extensional and bending stiffness (DIII) had the highest displacements and absorbable energies, and the variant designed for equal bending stiffness (DII) achieved intermediary results with values ranging appropriately when compared to QUAD. These results show that numerical simulation is able to reproduce the influence of stacking sequences on resistance and damage growth, which offers a more economical way to select laminate layups before experimental work. The simulations also indicate that the Double-Double design can result in distributed energy absorption due to increased delamination and matrix cracking, demonstrating its potential as a candidate design for impact-resistant structures.
Mudassar et al. (Thu,) studied this question.