脱层梁屈曲的高阶剪切理论

脱层的存在将会大大降低层合结构的屈曲载荷。该文将含任意位置脱层的两端固支梁分成多段子层，用厚度的三次多项式模拟脱层梁屈曲时子层的轴向位移，利用变分原理和欧拉方程导出了脱层梁的屈曲方程和定解条件，并用状态空间方法进行求解。通过与一阶剪切理论和经典理论的比较，指出了它们各自的适用范围；考虑了脱层梁三种不同的屈曲模态。分析了脱层长度、深度、位置和材料的铺层方向对脱层梁屈曲载荷的影响；最后给出了多处简单脱层的屈曲分析。

BUCKLING ANALYSIS OF DELAMINATED BEAM FOR THE HIGHER-ORDER SHEAR DEFORMATION THEORY

Delaminations may reduce the buckling load of the laminated structure greatly. In this paper, the clamped clampted beam including arbitrary delaminations in longitudinal and thickness is divided into multiple sublaminates whose longitude displacements are simulated with cubic function of the thickness coordinate. The variational principle and Euler equations are applied to obtain the governing equations and boundary conditions. The state space scheme is used to solve the problem. The applicability of the higher order shear deformation theory, the first order shear deformation theory and the classical theory, is discussed. Three different buckling modes of delaminated beam plate are considered. The influence of length, depth and position of the delaminations and ply orientation of the material on buckling load is analyzed. Finally, the buckling analysis of the multiply simple delaminations is made.