Alfredo H-S. Ang

Research Professor, University of California, Irvine

Minimizing the Effects of Uncertainties in Developing Reliability-Based Design Criteria
(click to view video)

Friday, April 19th, 2013 – 4:10 pm

Location: Sinclair Lab Auditorium, Lehigh University, 7 Asa Drive, Bethlehem, PA

Alfredo H-S. Ang, Research Professor, University of California, Irvine, CA: Dr. Ang is currently Research Professor and Professor Emeritus at the University of California in Irvine, California, USA. He is also Professor Emeritus at the University of Illinois at Urbana-Champaign since 1988 where he received his Ph.D. in 1959 and was on the faculty of Civil Engineering from 1959 through 1988. His main area of research is on the application of probability and reliability in civil and structural engineering, with emphasis on safety of engineering systems, including seismic risk and earthquake engineering, quantitative risk assessment (QRA), life-cycle cost and performance, sustainability of green buildings and infrastructure. He has published about 400 papers and articles, and also a two-volume textbook on probability concepts in engineering, which have been translated into several languages; the 2nd edition of Vol I was published in February 2007. During his academic career, he has directed 55 Ph.D. students and countless post-doctoral researchers from many parts of the world. He has given invited keynote papers and lectures in numerous major national and international conferences, including the 2009 Freudenthal Keynote Lecture at the ICOSSAR’09 in Osaka, Japan and the 2010 Kwang-Hwa keynote at the ISRERM2010 in Shanghai, China. During his career, he has been serving as consultant and technical adviser to government and industry on technological risk and reliability issues, both in the U.S. and abroad. He is a member of the prestigious US National Academy of Engineering (elected in 1976) and has received a large number of prestigious awards from the ASCE and other societies, including Honorary Membership in the ASCE.

Minimizing the Effects of Uncertainties in Developing Reliability-Based Design Criteria: Uncertainties are unavoidable in the analysis and design of engineering systems. Traditionally, engineers had to contend and dealt with significant uncertainties through conservative assumptions and applied safety factors to cover the effects of the underlying uncertainties. These assumptions and safety factors are invariably determined on the basis of engineering judgments; as such, the level of conservativeness is difficult to quantify. Proposed is a more scientific approach to handle uncertainties and to provide a systematic method to quantify and analyze their effects – namely, the reliability-based approach. The emphasis is to minimize the effects of uncertainties in the development of practical criteria for the design of infrastructure systems, including the formulation of safety factors and/or load/resistance factors in LRFD consistent with the corresponding level of uncertainties. Examples of real structures will be illustrated, including the optimal design based on minimum life-cycle cost.

The Fazlur R. Khan Distinguished Lecture Series has been initiated and organized by Dan M. Frangopol, the first holder of Lehigh's Fazlur Rahman Khan Endowed Chair of Structural Engineering and Architecture.