Risk optimization under random fatigue and corrosion processes

• Grant number: 09/17365-6
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): March 01, 2010
• Effective date (End): February 28, 2013
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal researcher: André Teófilo Beck
• Grantee: Wellison José de Santana Gomes
• Home Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 06/50594-0 - Numerical models development for structural engineering problems, AP.TEM

Abstract

Random corrosion and fatigue processes reduce the life of structures and mechanical components, and are responsible for many structural failures. Resistance reduction occurs slowly but gradually, leading to gradual increase in failure probabilities. Risk management for mechanical components subject to corrosion and fatigue is made by means of policies of inspection, maintenance, repair and substitution. These activities imply costs, but are made to maintain the reliability at acceptable levels, while the component remains in operation. Apparently, the objectives of economy and safety are concurrent, since a reduction in inspection and maintenance spending may scarify safety. However, larger and increasing failure probabilities lead to larger and increasing expected costs of failure (risk). Risk optimization is the proper tool to solve this problem, allowing one to find the best inspection and maintenance policy and the optimum amount of resources to allocate to such activities. This project aims at developing novel approaches to formulate and solve the optimization of risk under random corrosion and fatigue processes. It is proposed to describe the time evolution of these non-stationary processes by means of generalized chaos polynomials (series of deterministic functions indexed in random variables). Such a description allows an efficient solution of the underlying time-variant reliability problem, and the optimization of inspection and maintenance policies. This project is a direct contribution to Brazil's technological development, and finds applications to civil, off-shore and aeronautical structures. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GOMES, WELLISON J. S.; BECK, ANDRE T. Optimal inspection planning and repair under random crack propagation. ENGINEERING STRUCTURES, v. 69, p. 285-296, JUN 15 2014. Web of Science Citations: 9.

GOMES, WELLISON J. S.; BECK, ANDRE T. Optimal inspection and design of onshore pipelines under external corrosion process. STRUCTURAL SAFETY, v. 47, p. 48-58, 2014. Web of Science Citations: 32.

GOMES, WELLISON J. S.; BECK, ANDRE T.; HAUKAAS, TERJE. Optimal inspection planning for onshore pipelines subject to external corrosion. RELIABILITY ENGINEERING & SYSTEM SAFETY, v. 118, p. 18-27, OCT 2013. Web of Science Citations: 47.

DE SANTANA GOMES, WELLISON JOSE; BECK, ANDRE TEOFILO. Global structural optimization considering expected consequences of failure and using ANN surrogates. COMPUTERS & STRUCTURES, v. 126, n. SI, p. 56-68, SEP 15 2013. Web of Science Citations: 25.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GOMES, Wellison José de Santana. Risk optimization under random corrosion and fatigue processes. 2013. Doctoral Thesis - Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) São Carlos.