航空学报 > 2015, Vol. 36 Issue (5): 1539-1547   doi: 10.7527/S1000-6893.2014.0129

时变磨损间隙对机构可靠性的动态影响

刘育强1,2, 谭春林1, 赵阳2   

  1. 1. 北京空间飞行器总体设计部, 北京 100094;
    2. 哈尔滨工业大学 航天学院, 哈尔滨 150001
  • 收稿日期:2014-05-05 修回日期:2014-06-23 出版日期:2015-05-15 发布日期:2015-05-15
  • 通讯作者: 刘育强Tel.: 010-68745341 E-mail: echo33151223@sina.com E-mail:echo33151223@sina.com
  • 作者简介:刘育强 男, 博士研究生, 工程师。主要研究方向: 机械可靠性及多体系统动力学。 Tel: 010-68745341 E-mail: echo33151223@sina.com;谭春林 男, 博士, 研究员。主要研究方向: 航天器总体设计、航天器动力学。 Tel: 010-68746208 E-mail: chunlinTan973@sina.com;赵阳 男, 博士, 教授, 博士生导师。主要研究方向: 航天器多体动力学设计与仿真、碰撞动力学和试验模态测试技术。 Tel: 0451-86417756-801 E-mail: yangzhao@hit.edu.cn
  • 基金资助:

    国家"973"计划 (2013CB733000)

Dynamic effect of time-variant wear clearance on mechanical reliability

LIU Yuqiang1,2, TAN Chunlin1, ZHAO Yang2   

  1. 1. Institute of Spacecraft System Engineering CAST, Beijing 100094, China;
    2. School of Astronautics, Harbin Institute of Technology, Harbin 150001, China
  • Received:2014-05-05 Revised:2014-06-23 Online:2015-05-15 Published:2015-05-15
  • Supported by:

    National Basic Research Program of China (2013CB733000)

摘要:

为克服磨损速率恒定和磨损影响因素随机性假设带来的不足,并准确预测机构磨损可靠性的动态变化过程,利用等效弹簧阻尼接触碰撞力模型和磨损过程离散化方法,建立了关节间隙的时变磨损方程;引入PHI2方法、定义上穿率,将时变磨损方程转变成时变可靠性方程,从而提出了含时变间隙多体系统动力学和PHI2方法相结合的磨损可靠性分析方法。以某星载天线双轴定位机构为例,研究了产品可靠性及参数概率灵敏度的动态变化规律,分析了磨损各参数对产品可靠性的影响。结果表明,在稳定磨损阶段结束以前,接触碰撞力是主导因素,其对可靠性的敏感度是其他因素的10倍以上,此后,间隙将超过接触碰撞力,成为新的主导因素;且间隙存在临界情况,在此之前,间隙的适当增大有利于产品可靠性的提高。相比于现有研究强调磨损随机性、忽略磨损过程的非线性变化和间隙时变对可靠性的影响,所提方法能准确预示磨损及可靠性的动态变化过程。

关键词: 间隙, 磨损, 可靠性, 多体动力学, 定位机构, 星载天线

Abstract:

In order to overcome the drawbacks of constant wear rate and wear factors randomness hypothesis and to accurately predict the dynamic process of mechanical wear reliability, a time-variant wear equation of joint clearance is constructed by using a nonlinear equivalent spring-damp contact force model and discretization of wear process. Then, the joint wear evolution equation is converted into a time-dependent reliability equation by introducing a PHI2 method and defining an up-crossing rate. Therefore, a wear reliability analysis method which combines the mechanical multibody dynamics considering time-variant clearance with PHI2 is put forward. At last, by taking a two-axis positioning mechanism of satellite antennas as an example,dynamic reliability of the mechanism, parameters reliability sensitivity and their influence on reliability are studied. Results show that contact force is the dominant factor of reliability which is 10 times sensitive than other factors before the end of the product's steady wear process stage, while joint clearance will be the new dominant factor of reliability after this stage. What's more, there is a critical value for joint clearance, and appropriate augmentation of joint clearance before this critical value is propitious to the improvement of product's reliability. Compared to the current methods where randomness is emphasized, while the nonlinear process of wear and the consequence of concomitant time-variant clearances to product reliability are neglected, the present method could accurately analyze the dynamic process of wear and wear reliability.

Key words: clearance, wear, reliability, multibody dynamics, positioning mechanisms, satellite antennas

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