Bending creep property of wood-aluminum hybrid laminated material

Abstract

In this study, we manufactured six types of three-ply hybrid laminated materials reinforced by laminating aluminum alloy laminae on sugi wood (Japanese cedar), and investigated the influence of aluminum lamina thickness and lamina arrangement on the material's bending creep properties. The initial deformation of aluminum was 0.11-0.13 times that of sugi wood and the initial deformation of hybrid laminated material decreased markedly with increasing thickness of aluminum lamina. The creep deformation of aluminum was 0.37 (1 mm thickness), 0.04 (2 mm thickness) and 0.07 (3 mm thickness) times that of sugi wood, and creep deformation of hybrid laminated material except for that with 1 nun thick laminae became considerably smaller than that of sugi wood. The extent of the decrease in initial deformation was greater in the H type whose aluminum laminae were laminated horizontally on the upper and lower sides of a radial section of sugi wood lamina than in the V type whose aluminum laminae were laminated vertically on both sides of a tangential section of sugi wood lamina, whereas for 2 or 3 mm thicknesses the extent of the decease in the creep deformation was greater in the V type. The measured values of initial deformation and creep deformation of hybrid laminated material were greater than the values calculated from the measured values of aluminum and sugi wood. For the H type with 2 or 3 mm thick aluminum lamina, the ratios of measured to calculated value were considerably greater for creep deformation than for initial deformation. The ratios for both deformations were smaller for the V type than for the H type, and for hybrid laminated material with 2 or 3 mm thick aluminum, they were found to be considerably smaller in the V type than in the H type. This is considered to result from the effects of deformation in sugi wood and in glue lines caused by shear forces.