His research interests include nonlinear structural analysis, numerical methods, and computer-aided engineering. He is a core developer of the OpenSees finite element analysis framework, which is used worldwide by structural engineering researchers and practitioners. In 2009 he won an NSF CAREER award as well as the ASCE Croes Medal. That same year, he was recognized as an Outstanding Reviewer by ASCE's Journal of Structural Engineering. He has been an associate editor of JSE since 2010. He also serves on the Structural Engineering Institute's committees on Emerging Computing Technology and Methods of Analysis.