考虑法向载荷变化的Iwan模型及其特性分析

发布时间：2018-01-15 08:32

本文关键词：考虑法向载荷变化的Iwan模型及其特性分析　出处：《哈尔滨工业大学学报》2017年10期 　论文类型：期刊论文

【摘要】：为了完整、准确地复现摩擦接触界面间的力学行为和描述其能量耗散特性,提出了一种考虑法向载荷变化的Iwan模型.在连接界面的法向上,该模型采用一个非线性弹簧来描述界面法向载荷变化和间歇性分离的行为,在其切向上则采用原始Iwan模型来描述界面间的微滑和宏滑行为;推导了切法向耦合作用下模型的恢复力和位移关系的表达式,给出了模型运动状态转换点的判据;并以简化的摩擦阻尼器模型为对象,求解了振动系统在简谐激励作用下的动力学响应,讨论了不同激励参数对系统动力学特性的影响.分析表明,当法向载荷为常值时,该模型退化为Iwan模型,从而验证了模型的准确性;该模型考虑了切向微滑行为和法向载荷变化的动态耦合,相比于不考虑法向载荷变化的模型能够更加完善、准确地模拟接触界面间的力学行为及其对系统振动响应预测的影响;连接界面的法向分离不仅会减弱系统的阻尼性能,使得系统动响应很高,而且会增强系统响应的非线性程度,在实际工程应用中应尽量避免.
[Abstract]:In order to completely and accurately reproduce the mechanical behavior of friction contact interface and describe its energy dissipation characteristics, a Iwan model considering the variation of normal load is proposed, which is normally upward at the interface. In this model, a nonlinear spring is used to describe the behavior of normal load variation and intermittent separation of the interface, while the original Iwan model is used to describe the interfacial microgliding and macro gliding behavior in its tangent direction. The expression of the relationship between the restoring force and the displacement of the model under tangential coupling is derived, and the criterion of the transition point of the model motion state is given. Taking the simplified friction damper model as the object, the dynamic response of the vibration system under simple harmonic excitation is solved, and the influence of different excitation parameters on the dynamic characteristics of the system is discussed. When the normal load is constant, the model degenerates to Iwan model, which verifies the accuracy of the model. The model takes into account the dynamic coupling between the tangential micro-slip behavior and the normal load variation, which is more perfect than the model without considering the normal load variation. The mechanical behavior of the contact interface and its influence on the prediction of the vibration response of the system are simulated accurately. The normal separation of the connecting interface not only weakens the damping performance of the system and makes the dynamic response of the system very high, but also enhances the nonlinearity of the system response, which should be avoided in practical engineering applications.
【作者单位】：西北工业大学航天学院;
【基金】：国家自然科学基金委和中国工程物理研究院联合基金资助(U1530139)
【分类号】：TH113
【正文快照】： 航空、航天和机械等工程系统中的复杂结构大多是子部件通过螺栓法兰、过盈配合等连接形式装配而成.振动环境下,连接界面受到周期性外载荷作用,在法向可能出现预紧力振荡、界面分离和碰撞,在切向可能发生黏着、摩擦和滑动等行为.这些行为往往具有非线性、跨尺度、不确定性等特

【相似文献】