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中文核心期刊

机械结合面切向接触阻尼计算模型

A CALCULATION MODEL FOR TANGENTIAL CONTACT DAMPING OF MACHINE JOINT INTERFACES

  • 摘要: 针对两粗糙表面在法向力和切向力共同作用下相互接触时结合面切向阻尼的问题进行了研究。首先,根据KE模型对单个微凸体在弹性、弹塑性、塑性变形阶段的切向接触行为进行了分析,获得了微凸体在三个变形阶段的黏滑特性;然后,基于GW统计模型建立了一种在微凸体法向弹性、弹塑性和塑性变形机制基础上,考虑微凸体黏滑摩擦行为的机械结合面切向接触阻尼统计模型;最后,分别讨论了机械结合面的法向预载荷、切向激振频率和切向动态位移幅值对机械结合面切向阻尼的影响。研究表明:结合面切向接触阻尼系数随着结合面法向载荷的增大而增大,随着切向激振频率和切向动态位移幅值的增大而减小;在高频率、大幅值下,结合面切向接触阻尼系数几乎与动态位移幅值和激振频率无关。为了验证模型的准确性,构建了动态切向力作用下的结合面切向阻尼试验,其试验结果与理论仿真变化规律与量级基本一致,从而证明了本文所提出的切向阻尼模型的有效性。

     

    Abstract: This paper is focusing on the problem of tangential contact damping to study when two rough surfaces contact under combined normal force and tangential force. Firstly, according to the KE model, the tangential contact behaviors of a single asperity in the elastic, elastic-plastic, and plastic deformation stages were analyzed, and then the stick-slip characteristics of asperity in the three deformation stages can be obtained. Secondly, according to GW statistical model, a statistical model of a mechanical interface tangential damping was built based on a type of “asperity-based” model of including asperity elastic, elastic-plastic and plastic deformation mechanism, which considered the asperity stick-slip tribology behavior in the three different deformation mechanisms. Finally, the effects of the normal preload of mechanical interface, vibrational frequency and tangential dynamic displacement amplitude on the mechanical interface tangential damping were respectively discussed. These conclusions can be obtained that: the tangential contact damping coefficient increases with the increase of the normal load on the mechanical interface, whereas decreases as the tangential excitation frequency and the tangential dynamic displacement amplitude increase. For the high frequency and bigger amplitude, the tangential contact damping coefficient of joint surface is almost independent of tangential relative displacement amplitude and vibration frequency. In order to verify the veracity of the proposed model, a tangential damping experiment of joint surface was established under a dynamic tangential force, and the results show that the simulation results of the proposed theoretical model are mainly consistent with the experimental results in the change rule and the order of magnitude, which proves that the tangential damping of the proposed model is correct and effective.

     

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