针对层合板在加工和服役过程中出现的结构损伤问题，提出基于差分法和改进粒子群算法的两阶段损伤定量检测方法。首先，采用单元弹性模量降低的方法定义了结构损伤单元，通过结构振动特性分析获得了不同损伤工况层合板数值模型的模态参数，运用差分法识别了损伤大致区域。其次，利用改进的粒子群算法定量计算损伤的精确位置和程度。所提算法通过待测结构模型和迭代更新后有限元模型模态参数的柔度矩阵构建目标函数，引入变异因子以使算法有效的跳出局部收敛，MS算子减少了健康单元对真实损伤单元损伤程度的影响。结果表明：基于改进的粒子群算法可精确识别复合材料层合板结构损伤单元的位置和损伤程度。

A two-stage quantitative damage detection method based on difference method and improved particle swarm optimization algorithm was proposed to solve the structural damage problem of laminates during processing and service. Firstly, the structural damage element was defined by the method of reducing the elastic modulus of the element, and the modal parameters of the numerical model of the laminate under different damage conditions were obtained by analyzing the structural vibration characteristics. Secondly, an improved particle swarm optimization algorithm was used to quantitatively calculate the exact location and degree of damage. The proposed algorithm constructed the objective function through the flexibility matrix of the modal parameters of the tested structural model and the iteratively updated finite element model. The variation factor was introduced to make the algorithm effectively escape the local convergence. The MS operator greatly reduced the influence of the healthy element on the damage degree of the real damaged element. The results show that the improved particle swarm optimization algorithm can accurately identify the location and damage degree of the damaged elements in the composite laminates.