Damage Assessment on the Surface and Honeycomb Core of the Aluminum Sandwich Panel Subjected to Low-Velocity Impact

Sandwich panels consisting of aluminum face-sheets and honeycomb core are widely used in transportation systems. The composite structure has a high stiffness and strength, but it is susceptible to impacts in service. An experimental investigation of surface deformation and core damage in a honeycomb sandwich panel subjected to three different low-velocity impact energies was undertaken. Surface damage evaluation using 3D laser scanning technology was conducted to assess the surface damage and a comparison was made with two typical indentation profiles which were proposed mathematically in the past. The experimental dent profile shows a good agreement with one of the two analytical dent profiles. The impacted sandwich panel was then cut transversely to study the damage inside the honeycomb core. The number of buckled or collapsed folds under the damaged top face-sheet and the depth of the core damage were utilized as two parameters to quantify the damage of the honeycomb core. It is concluded that the core damage depth and the number of folds is independent of impact energy and is constant within each dent.