将半主动阻尼拉杆等效成质量和弹簧的二自由度模型，推导了动刚度表达式． 建立了基于线弹性、分数导数和摩擦模型的橡胶衬套非线性模型，采用 Maxwell 模型来描述广义阻尼器动刚度． 利用最小二乘法对衬套和广义阻尼器动刚度模型中的参数进行了识别． 通过实验和仿真计算对比了半主动阻尼拉杆在通电和不通电两种工况下的动刚度值．分析了等效弹簧刚度、阻尼常数和衬套刚度对半主动阻尼拉杆动刚度和阻尼性能的影响．结果表明:当衬套刚度、等效弹簧刚度和阻尼常数较大时，半主动阻尼拉杆的动刚度较大;增加阻尼常数能提高半主动阻尼拉杆低频时的动刚度，降低等效弹簧刚度和衬套刚度可以减小高频时的动刚度;衬套刚度对阻尼性能影响较小;等效弹簧刚度和阻尼常数越小，半主动阻尼拉杆阻尼性能越好．

In this paper,first,a semi-active hydraulic damping strut is made equivalent to a two-DOF model of mass and spring,and a dynamic stiffness expression is derived.Next,a nonlinear rubber bushing model based on the linear elasticity,the fractional derivative and the friction model,is constructed,and the Maxwell model is adopted to describe the stiffness of a general damper.Then,the parameters in the dynamic stiffness model of the rubber bushing and the general damper are identified by means of the least square method.Finally,the dynamic stiffness of the semi-active hydraulic damping strut under power-on conditions is compared with that under power-off condition through experiments and simulations,and the influence of the equivalent spring stiffness,the damping constant and the rubber bushing stiffness on the dynamic stiffness and damping capacity of the semi-active hydraulic damping strut is analyzed.The results show that (1) the dynamic stiffness of the semi-active hydraulic damping strut increases with the increase of the rubber bushing stiffness,the equivalent spring stiffness and the damping constant; (2) increasing the damping constant helps to improve the dynamic stiffness of the semi-active hydraulic damping strut at low frequencies,and decreasing the rubber bushing stiffness and the equivalent spring stiffness helps to reduce the dynamic stiffness of the semi-active hydraulic damping strut at high frequencies; (3) the ru- bber bushing stiffness has a smaller effect on the damping capacity of the semi-active hydraulic damping strut; and (4) the smaller the equivalent spring stiffness and the damping constant are,the better the damping capacity of the semi-active hydraulic damping strut will be.