摘要
由于重力或装配应力等偏置力的影响,隔振元件的工作状态将会偏离原始平衡位置,进而产生具有非对称特性的动力学行为,其具体表现为系统的动态响应存在刚性漂移现象,且该刚性漂移的大小与外激励频率、幅值均存在复杂的关系;其次,由于振动传感器主要针对动态信号,对于零频附近的低频信号存在灵敏度低、测量误差大的缺陷。因而,对于系统响应中存在的刚性漂移信号,实验中往往无法准确测定,甚至可能丢失,这将给系统的动力学参数标定带来非常大的影响。本文针对该问题,建立了此类隔振实验装置的非对称动力学模型,并利用较为成熟的谐波平衡原理构造了一种简单的迭代算法,使其在刚性漂移信息缺失的情况下,仍然能够有效地辨识得到系统结构参数。通过数值仿真,验证了该算法的有效性,并将其应用于一款具体的隔振元件动力学参数辨识工作中。其结果表明,由该算法辨识得到的结构参数与系统真实动力学特性具有较高的吻合度,对于其它具有类似特性的隔振元件的设计及应用具有一定的参考价值。
When the vibration isolator stays in a biased situation induced by gravity, assembly stress etc. , there will be a complex dynamic phenomenon with unsymmetrical characteristic such as rigid drift of the systems＇s dynamic response. Besides, this kind of drift has intimate relationship with external exciting frequency and its amplitude. On the other hand, the vibration sensors mainly suit for the measurement of dynamic signals. Therefore, there will be some deficiencies like blunt sensitivity and low accuracy in the measurement of nearly constant and slowly varying signals. When these sensors are applied to the experiment of the unsymmetrical systems mentioned above, the rigid drift data will be measured inaccurately or even lost, which can cause great difficulty to the system＇s parameter identification. According to this problem, a simple iteration algorithm based on the principle of harmonic balance was constructed for the parameter identification of unsymmetrical dynamic systems so that the identification is still efficient in the case of the losing the rigid drift information. As a numerical simulation example, the algorithm has been successfully applied to the parameter identification of a real vibration isolator. The results show that the identified parameters have satisfying coincidence with the experimental ones.
出处
《振动与冲击》
EI
CSCD
北大核心
2013年第6期18-23,共6页
Journal of Vibration and Shock
基金
国家自然科学基金(11032009)
关键词
非线性系统
参数辨识
谐波平衡
非对称
刚性漂移
nonlinear system
parameter identification
harmonic balance
unsymmetrical system
drift
