• Surface-based cohesive behavior
• Low-velocity impact events
• Continuum Damage Mechanics
• Compression-after-impact tests.
• Surface-to-surface contact pairing

Delaminations represent a damage mechanisms of paramount interest for composite laminates addressed to aircraft applications, mainly because of their difficult detectability even during ordinary inspections implying in worst cases a dramatic residual strength breakdown.
Effective numerical simulation of delaminations in composite structures could result useful to contrast increasing costs due to experimental campaigns as well as maintenance costs.
Through the simulation of increasingly complex models, starting from simple specimen to the more demanding stiffened-panels, and the comparison with elder modeling techniques, accuracy and performances are assessed.
Therefore comparisons with low velocity impact tests and compression after impact test results on multi-directional laminates are given.
A technique to extract damage by impact simulations and to inject it in different models is developed via Python scripting.
Finally, a compression-after-impact test on a reference two-bays lower panel is simulated and related results are given.