Aluminum–GFRP hybrid square tube beam reinforced by a thin composite skin layer

Ultimate bending moments and energy-absorption capability of aluminum–glass fiber reinforced plastic (GFRP) hybrid tube beams were experimentally analyzed with particular focuses on effects of thin GFRP skin layer in relation to bending deformation behavior and fracture characteristics. Various hybrid tube beams were fabricated by inserting adhesive film between prepreg and metal layers and by aligning various composite ply angles. Under 3-point bending loads, aluminum–GFRP hybrid tube beams showed characteristic fracture processes according to the lay-up kinds of the skin layer in comparison to the virgin aluminum tube beams. In particular, the hybrid tube beams having a 0.5 mm thick [0°/90°]s skin layer showed the largest improvement in specific maximum moment (about 67%) and in specific energy-absorption (29%). Consequently, there was an optimal thickness and lay-up of the composite skin layer in creating the best performance of the hybrid tubes.