EFFICIENT METHODS FOR MECHANICAL AND STRUCTURAL RELIABILITY ANALYSIS AND DESIGN (SAFETY-INDEX, FATIGUE, FAILURE).

http://hdl.handle.net/10150/187685
Title:
EFFICIENT METHODS FOR MECHANICAL AND STRUCTURAL RELIABILITY ANALYSIS AND DESIGN (SAFETY-INDEX, FATIGUE, FAILURE).
Author:
WU, YIH-TSUEN.
Issue Date:
1984
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Three fundamental problems of mechanical reliability are addressed. (1) computing the probability of failure, p(f), of a component having design factors with known statistical distributions and a limit state with a closed form algebraic expression (2) computing the probability of failure of a component having design factors with known distributions and a limit state which can only be expressed by a computer algorithm, and (3) deriving safety check expressions in a "design by reliability" approach. An algorithm for generating estimates of p(f) is presented. The method is an extension of, and demonstrated to be a significant improvement to, the widely used Rackwitz-Fiessler (R-F) method--a fast and efficient numerical method for performing reliability analysis. Comparisons were made for numerous examples, it was found that the error in p(f), using the proposed method, is typically about half of the error in R-F estimates. A method was proposed for computing p(f) when the relationship between design factors can be defined only using a computer algorithm, e.g., finite element analysis. A second order polynomial is constructed, using a simple curve fitting routine, to approximate the limit state in the neighborhood of the design point (i.e., a point close to the most likely value of the design variables at failure). Then the R-F method can be applied easily. It is demonstrated that this scheme is much faster than the Monte Carlo method in producing reasonable estimates of p(f). Methods of deriving safety check expressions for design codes and design criteria documents are studied. A Level I format employing partial safety factors derived from Level II methods is used to construct the safety check expressions which are suitable for code development. The procedures are demonstrated using numerous examples which include the problems where the limit states are complicated, i.e., the limit states are not explicitly defined.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Reliability (Engineering) -- Analysis.; Reliability (Engineering) -- Design.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Aerospace and Mechanical Engineering; Graduate College
Degree Grantor:
University of Arizona
Wirsching, Paul H.

DC FieldValue Language
dc.language.isoenen_US
dc.titleEFFICIENT METHODS FOR MECHANICAL AND STRUCTURAL RELIABILITY ANALYSIS AND DESIGN (SAFETY-INDEX, FATIGUE, FAILURE).en_US
dc.creatorWU, YIH-TSUEN.en_US
dc.contributor.authorWU, YIH-TSUEN.en_US
dc.date.issued1984en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThree fundamental problems of mechanical reliability are addressed. (1) computing the probability of failure, p(f), of a component having design factors with known statistical distributions and a limit state with a closed form algebraic expression (2) computing the probability of failure of a component having design factors with known distributions and a limit state which can only be expressed by a computer algorithm, and (3) deriving safety check expressions in a "design by reliability" approach. An algorithm for generating estimates of p(f) is presented. The method is an extension of, and demonstrated to be a significant improvement to, the widely used Rackwitz-Fiessler (R-F) method--a fast and efficient numerical method for performing reliability analysis. Comparisons were made for numerous examples, it was found that the error in p(f), using the proposed method, is typically about half of the error in R-F estimates. A method was proposed for computing p(f) when the relationship between design factors can be defined only using a computer algorithm, e.g., finite element analysis. A second order polynomial is constructed, using a simple curve fitting routine, to approximate the limit state in the neighborhood of the design point (i.e., a point close to the most likely value of the design variables at failure). Then the R-F method can be applied easily. It is demonstrated that this scheme is much faster than the Monte Carlo method in producing reasonable estimates of p(f). Methods of deriving safety check expressions for design codes and design criteria documents are studied. A Level I format employing partial safety factors derived from Level II methods is used to construct the safety check expressions which are suitable for code development. The procedures are demonstrated using numerous examples which include the problems where the limit states are complicated, i.e., the limit states are not explicitly defined.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectReliability (Engineering) -- Analysis.en_US
dc.subjectReliability (Engineering) -- Design.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAerospace and Mechanical Engineeringen_US