基体损伤对分层复合材料加筋板动力特性的影响研究

基于Mindlin假定的复合材料层合板单元和层合梁单元,推导了复合材料加筋板的刚度阵和质量阵;采用Adams应变能法与Rayleigh阻尼模型相结合的方法,构造了相应的阻尼阵列式;建立了分层损伤特征的三板模型和表征基体微裂纹损伤的基体损伤模型;并推导了一种基于Hertz型非线性接触法则的虚拟联接单元模型,以避免在振动分析过程中在低阶模态中分层处出现的上、下子板间不合理的嵌入现象;在上述模型和理论基础上,采用精细积分法求解含损伤结构的动力响应。对典型数例进行参数讨论,表明在动载荷作用下,嵌入分层损伤以及在振动过程中诱发的基体微裂纹损伤的演化将明显地影响加筋层合板的动力特性。

THE EFFECT OF MATRIX DAMAGE ON DYNAMIC CHARACTERISTICS OF COMPOSITE STIFFENED DELAMINATED PLATES

The element stiffness and mass matrices for the stiffened composite laminated plate is derived based on Mindlin deformation assumption. A damping model is constituted by using Rayleigh damping model in conjunction with Adams’ strain energy method (MSE). A three-plate model for describing the delamination and a multi-scalar model for describing the micro-cracks damage are established. To avoid the overlap phenomenon between the upper and lower sub-laminates at the delaminated region during dynamic analysis process, a nonlinear interface element is constructed according to Hertz contact law. A precise time-integration method is used to calculate the dynamic response analysis for the damaged stiffened composite plate. Numerical results show that the interaction between the imbedded delamination and the induced matrix’s crack during the dynamic process affects the dynamic response of the stiffened composites plates significantly.