Methods for estimating structural reliability using probability ideas are well established. When the residual ultimate strength of a buried pipeline is exceeded the limit, breakage becomes imminent and the overall reliability of the pipe distribution network is reduced. This paper is concerned with estimating structural failure of underground flexible pipes due to corrosion induced excessive de...

Optimization techniques are essential ingredients of reliability-oriented optimal designs of technical facilities. Suitable objective functions are presented for different replacement strategies for structural facilities. Within FORM/SORM structural reliability analysis can be reduced to an optimization task and some simple algebra. However, instead of a optimization of cost on top of a optimiz...

Treatment of uncertainties in structural design involves identifying the boundaries of the failure domain to estimate reliability. When the structural responses are discontinuous or highly nonlinear, the failure regions tend to be an island in the design space. The boundaries of these islands are to be approximated to estimate reliability and perform optimization. This work proposes Alpha (α) s...

The most common approach to assess the safety of a bridge is load rating. However, this approach cannot quantify the bridge safety in probabilistic terms or fully quantify the structural risk to the bridge. Reliability methods have become an increasingly popular and gradually accepted approach to assess the safety of structures. These methods account for the randomness and correlation of all re...

After examining the specific problems of testing and quality assurance for web-based applications, we propose a strategy by integrating existing testing techniques and reliability analyses in a hierarchical framework. This strategy combines various usage models for statistical testing to perform high level testing and to guide selective testing of critical and frequently used subparts or compon...

Importance measures in reliability engineering are used to identify weak areas of a system and signify the roles of components in either causing or contributing to proper functioning of the system. Traditional importance measures for multistate systems mainly concern reliability importance of an individual component and seldom consider the utility performance of the system. This paper extends t...

dear editor multiple choice tests are the most common objective tests in medical education which are used to assess the ind­ividual knowledge, recall, recognition and problem solving abilities. one of the testing components is the post-test analysis. this component includes; first, qualitative analysis of the taxonomy of questions based on the bloom’s educational objectives and percentage of th...

Within many engineering fields, structural design must meet the demands of cost-effectiveness. This leads to lightweight, highly flexible, and consequently vulnerable structures. In order to assess potential risks associated with such a design, the structural analysis must take into account available information on the randomness of loads and structural properties. It means that the analysis sh...

Title of Document: ADVANCED METHODOLOGIES FOR RELIABILITY-BASED DESIGN OPTIMIZATION AND STRUCTURAL HEALTH PROGNOSTICS. Pingfeng Wang, Doctor of Philosophy, 2010 Directed By: Dr. Byeng D. Youn, Assistant Professor, Department of Mechanical Engineering. Failures of engineered systems can lead to significant economic and societal losses. To minimize the losses, reliability must be ensured througho...

In reliability and robustness analysis, imperfections of a mechanical or structural system, such as material properties or geometrical deviations, are modelled as random fields in order to account for their fluctuations over space. A random field normally comprises a huge number of random variables. The present paper proposes a method to reduce the random variables set. This reduction is perfor...