磁流变减振器滞回特性的改进Bouc-Wen模型

摘要

由于现有的磁流变减振器数学模型不能准确描述其特性,因此对大行程磁流变阻尼器进行了动态特性试验.根据测试结果分析激励位移、激励频率和电流变化时,磁流变减振器的弹性、阻尼、电流饱和等基本特征的动态非线性特性.已有的Bouc-Wen模型在低速下滞回环描述不准确,在高速下缺少滞回特性,并且无法表述单出杆减振器中蓄能器造成阻尼力偏置的现象,因此根据试验结果提出一种改进的Bouc-Wen模型,通过试验数据对改进的Bouc-Wen模型进行参数辨识,并重点分析速度-力特性曲线在低速与高速情况下所形成滞环的斜率及宽度,试验数据验证了改进Bouc-Wen模型的正确性.%The existing mathematical model of magneto-rheological damper ( MRD) could not describe its characteristics correctly, so dynamic characteristic test on large scaled MRD was carried out. According to the test data, the dynamic nonlinear feature on elastic, damping and current saturation characteristics of MRD was analyzed with variable excitation displacement, excitation velocity and controlling current. Bouc - Wen model was not accurate enough to reflect hysteretic loop in low speed and lack hysteretic characteristics in high speed. It was also unable to express the offset phenomenon of damping force caused by pressure accumulator in single rod damper. Thus, a modified Bouc - Wen model was established. The parameters of the new model were identified with the test data, and the slope and width of hysteretic loop in velocity-force curves under high and low speed emphatically analyzed. The modified Bouc - Wen model was verified by experiment data finally.