基于Bouc-Wen模型辨识结合面动态特性研究

Dynamic characteristics identification of joint interfaces based on a Bouc-Wen model

结合面复杂的粘着-滑动和间隙-碰撞动力学行为通常是采用线性化的刚度和阻尼来模拟,忽略了本身的迟滞非线性特性。为真实反映结合面性质,提出将结合面特性等效为Bouc-Wen模型,并对模型中各未知参数进行范围限制和灵敏度分析。针对Bouc-Wen模型中参数的灵敏性,分别采用力和位移两种控制方式,运用最小二乘法对不同噪声扰动下的数据进行参数辨识,分析不同噪声扰动对辨识结果的影响,以及各控制方式对辨识结果的影响,从而验证采用Bouc-Wen模型等效结合面的迟滞非线性的合理性,和采用等效线性化的辨识方法的正确性。算例表明:在信噪比小于5%的噪声扰动下,对模型中各未知参数的辨识精度影响较小;采用位移控制方式辨识出的结果比采用力控制方式辨识的结果更加准确。

The dynamic model of joint interfaces is usually characterized with a number of linear spring-damping elements, it cannot reflect the hysteresis nonlinear characteristics of joint interfaces with stick-slip and separation-slap. Here, its dynamic beharior was equivalent to a Bouc-Wen model. Then, the range of parameters in the model was restricted and sensitivity analysis was conducted for each parameters. Finally, the parameters of Bouc-Wen model were identified with the least square method under different forces cotrolled and displacements cotrolled, the identified results under the forces controlled and those under the displacements controlled were compared, and the effects of different noise disturbances on the identified results were also analyzed. The simulation results showed that the better identified results can be obtained under the displacements controlled, and under the noise disturbance with a signal to noise ratio of less than 5% , its effects on the identified accuracy of the parmeters of Bout-Wen model are little.