Keywords: 
• forest engineering /
• wood-bamboo composite laminate /
• hygro-effect /
• classical laminated plate theory /
• first-order shear deformation theory

Abstract: 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. ［Ch，1 fig. 3 tab. 8 ref.］