| 摘要 |
A carbon-fiber reinforced plastics sheet (CFRP) is excellent in tensile strength and modulus of elasticity, but defective in impact resistance and fracture toughness, To overcome the defect, two aromatic polyamide fiber reinforced plastics sheets (KFRP) are adhered to the opposite surfaces of the carbon-fiber reinforced plastics sheet (CFRP) to thereby provide a laminated structure, whereupon aramid fibers (a) are skewed at angles of +30 DEG - +60 DEG with respect to the direction of an impact load. This arrangement exhibits an improved shock absorbing efficiency and eliminate surface distortion which would otherwise take place during lamination. Further, a shock-absorbing structure may be produced from combining a plurality of sheets (1, 2) assembled crosswise such that surfaces of the respective sheets lie parallel to the direction of the impact load, and a cutout recess (5) and a bulged portion (6) are formed at an end of the sheet adjacent an intersection (3) of the structure. Thus, the one end of the sheet including the cutout recess (5) and the bulged portion (6) undergoes local buckling initiating from the intersection (3), and thereafter the entire assembly is caused to become buckled. Since complete buckling of the entire structure takes a certain period of time during which the impact energy can be absorbed with reduction of the peak load, the shock-absorbing structure is suitable for use in a crushable zone in aircrafts, automobiles or the like. <IMAGE> |
