The DuraFuse Frame was developed between 2014 and 2018 by Dr. Paul Richards.
Dr. Richards did his graduate work at the University of California, San Diego (UCSD) in the years following the 1994 Northridge earthquake. As a graduate student, Dr. Richards was involved in the experimental validation of moment connections with deep columns for use in California hospital projects. The connections that Dr. Richards helped to investigate are typical of the rigid connections in AISC 358-16, where the beams are sacrificed in order to accommodate large drifts and dissipate earthquake energy.
As a graduate student, Dr. Richards wondered, “what is going to happen to our buildings after an earthquake, if the moment frame beams are all damaged?”
Expected beam damage for AISC 358-16 rigid moment frames.
The 2011 Christchurch earthquake illustrated the consequences of sacrificing structural elements. While few structures collapsed, many code-compliant buildings that survived the shaking were damaged beyond repair and had to be demolished later.
Dr. Richards was a faculty member at Brigham Young University (BYU) at the time of the 2011 Christchurch earthquake. Following the earthquake, he refocused his research efforts on developing a more resilient steel moment frame. He explored a number of concepts, but all were more expensive than current practice and unlikely to see widespread use.
In 2016, Dr. Richards developed the concept of the shear-yielding fuse plate. Initial tests of the first DuraFuse Frame were conducted at the end of 2016 with a W14x38 beam and W14x48 column. The prototype tests confirmed that the connection was viable for special moment frames.
In 2017, Dr. Richards teamed up with experienced fabricators to develop a version of the connection that could be commercially competitive. Throughout 2017 and 2018, several series of full-scale experiments were performed at BYU and UCSD to demonstrate that the DuraFuse connection could be pre-qualified as a special moment frame connection. By the end of 2018, over 20 qualifying tests had been completed with beam sizes ranging from W21x to W40x and column sizes ranging from W14x to W36x. In each series of tests, the same beam and column were used multiple times, just replacing the fuse plate after each test.
Qualification testing for a DuraFuse Frame connection at UCSD.
DuraFuse Frames, LLC was established at the end of 2018 to facilitate the use of DuraFuse Frames in professional practice. DuraFuses Frame, LLC provides design assistance to structural engineers and coordinates license fees with steel fabricators. Licenses are granted, on reasonable and nondiscriminatory terms, to anyone who would like to use the connection. Even with the license fee, DuraFuse Frames are less expensive than other (low-resilience) moment frame alternatives.
