ANALYSIS OF DAMAGE IN LOW-VELOCITY IMPACT-TESTED GFRP-ALUMINUM HONEYCOMB SANDWICH PANELS USING MATLAB

Honeycomb sandwich structures are widely utilized in civil infrastructure applications due to their exceptional mechanical properties. To assess their damage tolerance and strength, low-velocity impact (LVI) tests are commonly performed. This study investigates the damage tolerance of a polyester pin-incorporated foam-filled honeycomb sandwich panel (PFHS) through LVI experiments, comparing it to a conventional foam-filled honeycomb sandwich panel (FHS). The comparison focuses on damage assessment metrics such as damaged area and microscopic examination of the damaged surface. Due to indistinct colors and irregular shapes of damage of LVI-tested panels, visual inspection methods often struggle to accurately determine the damaged area. To address this limitation, this study introduces a cost-effective approach based on digital image analysis and MATLAB programming to precisely quantify the damaged area and assess damage severity without requiring advanced instrumentation. The proposed method proved to be efficient, with results closely matching those obtained through visual inspection. Furthermore, an addition of polyester pin reinforcement significantly enhanced the interlayer crack resistance of the foam-filled honeycomb sandwich panels, resulting in a notable reduction in the impact damaged area.