基于二维弹性力学理论,研究在轴向荷载作用下含脱层层合简支梁的屈曲模态.由位移法求得各单层梁受均布轴压时的弹性力学解,采用配点法联合各层得到整个系统的解.在层间界面上取与级数项数相等的点,将各点处的界面方程与梁上下表面的边界方程联立求解,得到屈曲临界载荷,返回特征方程得到梁的屈曲模态.研究了脱层界面的接触问题,在脱层处的每个配点上分别使用界面接触和界面自由模型进行计算,分析各配点处脱层表面竖向位移及法向应力的状态,迭代求得真实解.算例分析了不同脱层尺寸和脱层位置对层合梁屈曲模态的影响,并考虑了脱层间的接触.
Based on the two-dimensional elasticity theory,the buckling modes of delaminated composite beams were studied.Firstly,according to the plane elasticity theory,the analytical solution of a piece of homogeneous beam is obtained,which exactly satisfies the simply-supported conditions of the beam at two ends.Then,using the point collocation technique,taking the series terms equal to the matching points,the critical buckling loads were obtained by means of the interface equations at every points as well as the upper and lower surface conditions of the beam.The displacement modes of the beam are given by substituting the critical loads back to the eigenvalue equations.The possible contact on the delaminated interfaces is considered in the present study."Free" and "contact" modes are separately computed.According to the situations of the vertical displacements and normal stresses on the delaminated interfaces,the real buckling modes can be judged.The effects of the sizes and positions of the delaminations on the buckling modes were investigated.The present method is applicable not only to the slender beams,but also to the thick beams.And the contact problem was also well solved.