斜拉索－摩擦型阻尼器系统的阻尼特性分析

摘要

研究了采用非线性摩擦型阻尼器的斜拉索振动控制的阻尼特性。通过数值模拟斜拉索－摩擦型阻尼器系统的自由振动，分析了斜拉索位移时程曲线的衰减特征，系统模态阻尼比的变化规律以及拉索振动形状的变化。通过对拉索模态阻尼比的参数分析，得到了摩擦型阻尼器参数和拉索附加阻尼关系的通用设计曲线。研究了拉索－摩擦型阻尼器系统最大附加阻尼的取值，结果表明斜拉索的最大模态阻尼比依振动初始条件等参数影响分布在一个范围而非定值，其下限值仍高于采用线性黏滞阻尼器时所获得的最大模态阻尼比。最后将数值模拟结果与已有实索试验数据进行了对比，二者吻合良好。%Damping characteristics of a stayed cable nonlinear friction damper was studied.The free vibration of the cable-friction damper system was numerically simulated with the finite element method.The free vibration attenuation characteristics of the cable,the variations of the modal damping ratio of the system,and vibration shapes of the cable were analyzed.A universal design curve was proposed,it related the modal damping ratio of the cable to parameters of the damper when the effects of various parameters on damping were considered.The maximum additional damping of the system was studied.The results showed that the maximum modal damping ratio of the cable-friction damper is not a fixed value,but a range,and its lowest value is larger than that of an optimal passive linear viscous damper.The results of numerical simulation were compared with those of the actual test data,the former agreed well with the latter.