初始缺陷对复合材料层板稳定性的影响

Influence of initial imperfection on the stability of composite laminated plates

为深入研究初始缺陷对复合材料层板稳定性的影响 ,利用能量变分原理和考虑初始缺陷的非线性几何方程 ,建立了具有弹性约束的层合板在面内载荷作用下的非线性稳定性控制方程组 ,运用广义傅立叶级数法对其进行求解 ,并进一步获得了影响非线性稳定性控制方程组的性质的非齐次项。研究结果表明 ,非对称层合板带初始缺陷时 ,物理耦合和几何耦合既可能得到加强 ,也可能互相削弱 ,甚至在某些情况下耦合作用完全抵消 ,导致非齐次项为零 ,因而会出现屈曲。

The influence of initial imperfections on the stability of composite laminated plates was studied by solving the nonlinear governing equations for laminated plates with elastical restraints subject to in plane loading using the energy variational principle and nonlinear geometric equations incorporating the initial imperfection. The governing equations were solved using generalized Fourier series to obtain the effect of the non uniform order term. The investigation results showed that, with unsymmetrical laminated plates with initial imperfections, the physical coupling and geometric coupling effect may be either strengthened or weakened, or even canceled to induce buckling since the non uniform order term is sometimes equal to zero. The results were used to propose the concept of critical initial imperfection waveform.