Wilfred D. “Bill” Iwan, an ASCE Distinguished Member who was an innovator in engineering seismology and professor emeritus of civil engineering at California Institute of Technology, has died. He was 85.
If a single person can be said to have ensured that we knew when or where an earthquake could strike, it was he.
Iwan, Ph.D., Dist.M.ASCE, NAE, began and ended his career at Caltech. After earning three degrees from the school, he joined its faculty in 1964. Iwan served as the executive officer for Civil Engineering and Applied Mechanics in the Division of Engineering and Applied Science from 1980 to 1986, and became professor emeritus in 2004.
His research focused on the fundamental areas of mechanics, including understanding and characterizing ground motion and monitoring the response of structural systems subjected to extreme events; he also was involved in the development of public policy regarding disasters.
In 1979, he proposed an earthquake early-warning system for urban regions. His team developed methods to represent complex nonlinear structures with simpler linear systems, practical methods for earthquake-resistant design, and simplified methods for the analysis of seismic isolation systems for critical equipment.
Iwan’s special expertise made possible his concept of “Drift Demand Spectrum,” which has led to a better understanding of the damage potential of strong earthquake ground motion. His body of work greatly mitigated the dangers posed by seismic events and vastly improved public safety. Those grateful for that work include earthquake scientists as well as structural engineers.
Iwan was also director emeritus of Caltech’s Earthquake Engineering Research Laboratory, the founding president of the Consortium of Universities for Research in Earthquake Engineering, a founding director of the World Seismic Safety Initiative, and chair of the National Research Council Committee on Hazard Mitigation Engineering.
He was elected to the National Academy of Engineering in 1999 “for research on seismic performance of structures, and for leadership in earthquake hazard mitigation and improvement of public safety.” Besides his Distinguished Member status with ASCE (2009), the Society also awarded him the Nathan M. Newmark Medal (1997), the William H. Wisely Award (2006), and the Theodore von Kármán Medal (2013).
In 2002, the California Earthquake Safety Foundation awarded him the 2002 Alfred E. Alquist Medal for his lifetime of service to the profession. He was also an awardee of the Earthquake Engineering Research Institute’s George W. Housner Medal.