A comprehensive method of non-probabilistic time-varying reliability of link mechanism with hinge clearance

Abstract

The invention provides a method for synthesizing for non-probability time-varying reliability of a link mechanism containing a hinge gap. Firstly, according to the rod length and initial position of the link mechanism and specific characteristics of the hinge gap, a mathematic expression of a mechanism motion error function is obtained in combination with a vector method; secondly, rod length and hinge uncertainty information is introduced into an interval process model for establishing mechanism motion errors, and the time-varying uncertainty characteristic quantity of a mechanism motion precision limit state function is quickly calculated; thirdly, based on the first crossing theory and the dispersed strategy, index definition and solution of crossing failure possibility in any micro cyclic loading increment segment are completed, and then a time-varying reliability model is constructed; finally, the non-probability time-varying reliability index of motion precision serves as a target, non-probability reliability of mechanism existence conditions serves as a constraint condition, and synthesis of the non-probability time-varying reliability of the link mechanism containing the hinge gap is completed. In the process of mechanism synthesis, synthetic effects of uncertainty on the mechanism in a motion period are reasonably represented, and the time-varying reliability of the mechanism can be effectively improved.

Description

technical field [0001] The present invention relates to the field of comprehensive reliability technology of link mechanisms, in particular to the quantitative characterization of the motion accuracy of link mechanisms with hinge gaps under the joint action of time-varying and uncertainties and the optimization target based on the non-probability time-varying reliability index of motion accuracy Development of a comprehensive program for the reliability of the linkage mechanism. Background technique [0002] At present, the theory of analysis and optimal design of fixed structures has become increasingly mature, and accidents caused by failures of fixed structures are becoming less and less. It is becoming more and more prominent that the movement precision of the mechanism is often the most concerned issue of the designer. [0003] Due to machining errors, work wear and other reasons, hinge clearance is inevitable. Appropriate clearance can bring compensation for displace...

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Problems solved by technology

The above work has enriched the comprehensive theory of reliability of link mechanisms with hinge gaps to a certain extent, but there are still some problems: (1) When the sample information is sufficient, the probability and statistics theory is the best way to describe the uncertainty, However, in actual engineering, it is often impossible to obtain enough sample information; (2) The method of replacing the hinge gap with a massless rod only considers the continuous contact between the bearing and the shaft pin, while ignoring the free movement of the shaft pin in the gap circle ; (3) Mechanism movement is a process that changes with time. The current comprehensive method based on static reliability only considers the movement accuracy of the mechanism at any time, but ignores the time correlation of the movement error of the mechanism. Therefore, it is necessary to establish a definition in the complete Reliability metrics within the movement cycle of the mechanism, instant variable reliability

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