An Envelope Approach to Time-dependent Reliability Analysis for Mechanisms

Abstract

This work is concerned with the time-dependent mechanism reliability defined over a period of time where a certain motion output is required. An envelope approach is proposed to improve the accuracy of the time-dependent mechanism reliability analysis. The envelope function of the motion error over the time period is created. Since the envelope function is not explicitly related to time, the time-dependent problem is converted into a time-independent problem. Then the envelope function is approximated by piecewise hyperplanes. To find the expansion points of the hyper-planes, the approach linearizes the motion error at the means of random dimension variables, and this approximation is accurate because the tolerances or the variances of the dimension variables are small. Then the expansion points are found with the maximum probability density at the failure threshold. The time-dependent mechanism reliability is then estimated by a multivariable normal distribution function at the expansion points. As an example, analytical equations are derived for a four-bar function generating mechanism. The numerical example shows the significant accuracy improvement. Copyright © 2013 by ASME.

Department(s)

Mechanical and Aerospace Engineering

Comments

National Science Foundation, Grant CMMI 1234855

International Standard Book Number (ISBN)

978-079185589-8

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Society of Mechanical Engineers, All rights reserved.

Publication Date

01 Jan 2013

Link to Full Text

Share

 
COinS