复合材料板拉/压-剪复合载荷屈曲相关方程

利用轴向拉伸/压缩和面内剪切载荷构建了一个相互作用函数，并将其通过幂级数展开成二次多项式，利用单轴试验测试的复合材料板屈曲载荷，基于数学原理和合理的假设，推导确定了多项式的各项待定系数，构建了轴向拉伸/压缩和剪切复合载荷下的复合材料板屈曲相关方程，从数学上理性地解决了传统屈曲相关方程不适用于复合材料板（尤其是非均衡铺层板）的问题。利用提出的相关方程预测了4种不同的非均衡铺层复合材料板在轴向拉伸/压缩和剪切载荷作用下的屈曲相关曲线，并与有限元特征值法的模拟结果进行了对比，两者具有很好的一致性，而对于传统相关方程，其铺层的非均衡性越大则预测误差越大。最后通过均衡铺层的复合材料加筋壁板的压剪复合试验进一步证明了提出的相关方程的有效性。

Buckling interaction formulae of composite plates under combined axial compression/tension and shear loads

An interaction function is constructed using axial tension/compression and in-plane shear loads, and further expanded into a quadratic polynomial by power series. Based on mathematical principles and reasonable hypotheses, the polynomial coefficients are determined using the buckling load of the composite plate measured by a uniaxial test. The buckling interaction formulae of composite plates under combined axial tension/compression and shear loads are then established. The problem that the traditional buckling interaction formulae are not suitable for composite plates (particularly for unbalanced laminates) is thereby solved mathematically and rationally. The buckling interaction curves of four different unbalanced ply composite plates under axial tension/compression and shear loads are predicted with the interaction formulae proposed in this paper, and compared with the simulation results of the finite element eigenvalue method. The comparison shows a good agreement. For the traditional interaction formulae, the prediction error increases with the increasing unbalanced degree of composite laminates. Finally, the validity of the proposed interaction formulae is verified by the compression shear tests of composite stiffened panels with balanced laminates.