正交铺设层合板的蠕变屈曲分析

CREEP BUCKLING OF CROSS PLY LAMINATED PLATES

研究了正交铺设层合板的蠕变失稳问题．为了更好地模拟实际情况，在单层板的本构关系中，材料各主方向模量的松弛时间均取不同值，并在建立控制方程时考虑了横向剪切变形的影响．通过理论分析，得到了粘弹性层合板的瞬时弹性临界载荷和持久临界载荷．并在算例中首次利用时间增量方法得到了有初始挠度层合板在长期受载时的蠕变变形，计算结果表明了持久临界载荷对于粘弹性层合板的具体含义，从而使粘弹性层合板的蠕变屈曲问题有了较为完整的理论体系和数值方法．而且这种理论分析方法和计算方法可用于解决其它复合材料粘弹性板和壳的蠕变屈曲问题．

A creep buckling analysis of cross ply laminated plates is given. In order to simulate the real conditions, the relaxation time of modulus in the principal orientations of material is arbitrary in constitutive equations of lamina. In deriving the associated governing equations transverse shear deformations are incorporated. By means of theoretical analysis, the instantaneous critical load and durable critical load of viscoelastic laminated plates are obtained for the first time. In the example a time incremental mathod is used for the first time to calculate the deformation of the viscoelastic laminated plates with initial imperfection, subjected to a constant compressive load for a long time. The calculated result presents the meanings of the durable critical load. Thus a more complete theoretical and calculating system of creep buckling for viscoelastic laminated plates is obtained. Moreover, this deducing and calculating method can be used to solve the creep buckling questions of other viscoelastic composite plates and shells.