Date of Award

Spring 5-31-1992

Document Type


Degree Name

Doctor of Philosophy in Mechanical Engineering - (Ph.D.)


Mechanical and Industrial Engineering

First Advisor

Nouri Levy

Second Advisor

Harry Herman

Third Advisor

John Vincent Droughton

Fourth Advisor

E. S. Geskin


During the last decade, structural reliability theory has been treated in a large number of research papers; therefore, from being a subject only well known by a relatively small number of researchers, it has become an important engineering discipline. From the application point of view, many practical applications have been made successfully.

In this dissertation some important fundamental concepts in statistics and in reliability theory are presented. The concept of failure mode can be defined as: A set of failed elements turn a structure into a mechanism. Usually, a structure has many possible failure modes; therefore, it will be necessary to estimate the reliability with respect to each specified failure mode, and then to estimate the overall reliability of the structure from a system point of view. In this dissertation the methodology of using ANSYS finite element software to identity the failure modes is introduced in detail.

The modelling used in this dissertation is based on the assumption that the total reliability of the structure can be sufficiently accurately estimated by considering only a finite number of significant failure modes and then combining them in a complex reliability system. Usually, the reliability of a structural system is modeled by a series of failure modes each composed of failure elements assembled in parallel.