中文摘要：

研究了在简谐激励作用下复合材料加筋板基体微裂纹损伤的演化行为及其对加筋板动力特性的影响。基于平均微裂纹密度和断裂力学方法，建立了复合材料加筋板基体微裂纹演化的刚度退化准则。由于该准则考虑了载荷作用周期数的影响，从而能够更合理地分析周期性动载荷作用下基体微裂纹损伤演化规律。采用Mindlin一阶剪切理论和复合材料模态阻尼模型，建立了复合材料加筋板动力分析的有限元方法，研究了在简谐激励作用下，含分层损伤复合材料加筋板振动过程中诱发的基体微裂纹损伤的演化、刚度退化，频率折减和动力响应。

英文摘要：

The matrix damage evolution behavior and the effect of matrix micro-cracks on the dynamic characteristics of composite stiffened delaminated plates are studied. A stiffness reduction model considering matrix microcracks criteria is established. The model can be used to investigate the matrix damage evolution behavior under harmonic excitation effectively as the influence of the number of cycles has been taken into account. On the basis of Mindlin deformation assumption and the modal damping model, a dynamic numerical analysis for investigating the characteristics of damage evolution, stiffness reduction, natural frequency reduction and dynamic response of the delaminated stiffened composite plates has been carried out by the finite element method.