ENERGY ABSORPTION CHARACTERISTICS AND DEFORMATION PATTERNS IN FIBERGLASS FILLED CRASH BOX UNDER QUASI STATIC LOADING

This study investigates the crashworthiness of fiberglass filled crash box under quasi-static loading by varying filler height and central hole diameter. The crash box specimens consisted of 1.8 and 2.2 mm thick aluminum tubes with an outer diameter of 76 mm, filled with fiberglass. The fiberglass fillers were prepared in four height configurations: 30 mm, 60 mm, 90 mm, and 120 mm. To investigate the effect of crush initiators, a central axial hole was drilled through the fillers in three diameters: 24 mm, 28 mm, and 32 mm. Compression tests were conducted to evaluate energy absorption (EA), and specific energy absorption (SEA). Increasing filler height improved EA from 6.39 to 36.92 kJ. Central perforations acted as buckling initiators: a 24 mm hole offered the best performance, maintaining the highest EA (23.63 kJ). In contrast, a 32 mm hole triggered early collapse, reducing energy absorption. The results show that optimal combinations of filler geometry improve both energy absorption and structural stability. These findings offer a practical, cost-efficient design strategy for lightweight, crashworthy components, with potential application in sustainable automotive structures.