Joint Probability Method to Time-dependent Reliability for Planar Path Mechanisms

doi:10.3901/JME.2017.15.119

Abstract

Abstract: Time-dependent reliability method for mechanisms is used to predict the probability of satisfying the motion requirement in a predefined period of time. Since the kinematic time-dependent reliability embodies the overall motion situation of mechanisms, the nature of kinematic time-dependent reliability is a system reliability of mechanisms. The current time dependent kinematic reliability methodologies are mainly for function generating mechanisms and are unsuited to solve the reliability of path mechanisms. An innovative method based joint probability for reliability of path mechanisms is proposed. For path mechanisms, a failure occurs if the error in any direction of the path exceeds the allowable tolerance. There are then two failure modes for planar path mechanisms. The overall kinematic reliability is treated as the reliability of a series system consisting of failure modes in all directions, and each motion output component is also taken as a series system consisting of path discrete points. The time-dependent mechanism reliability is then estimated by the multivariable normal distribution function. The proposed method is evaluated and demonstrated by two planar four-bar path generating mechanisms.

Key words: joint probability, planar path mechanisms, time-dependent reliability

CLC Number:

TH112

CHEN Fang, LI Xinling, SHE Xia, LONG Yu, ZHANG Junfu. Joint Probability Method to Time-dependent Reliability for Planar Path Mechanisms[J]. Journal of Mechanical Engineering, 2017, 53(15): 119-124.

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