湿效应对竹木复合材料刚度性能的影响

Hygro-effect on stiffness properties for a wood-bamboo composite laminate

首先根据经典层合板理论和一阶剪切变形理论的基本假设,建立起相关的位移模式,进一步推导出考虑湿效应下竹木复合层合梁的势能函数表达式,然后运用材料力学的等效梁理论推导出考虑湿效应下的竹木复合层合梁的等效弹性模量。比较了不同理论下湿效应前后的等效弹性模量与弯曲变形。研究表明,吸湿比例达30%时,竹木复合材料的等效弹性模量损失逾一半,而同样载荷下弯曲变形则是原有的2倍。

To determine the potential energy function derived from a wood-bamboo composite laminate employing the hygro-effect, a displacement model was established based on assumptions of the classical laminated plate theory （CLPT） and the first-order shear deformation theory （FSDT）. Then, the equivalent elastic modulus of wood-bamboo composite laminate with the hygro-effect was derived according to the equal beam theory. Using several theories, a comparison of the equivalent elastic modulus and bending deformation was made before and after the hygro-effect was used. Results showed when moisture concentration increased up to 30%, the equivalent elastic modulus of bamboo and wood composite materials decreased more than half, and under the same load, bending deformation was twice that of the original.