Research

Bolted moment connections can be prequalified for both new construction and retrofit

DuraFuse moment connections are a bolted alternative to welded or proprietary cast SMF connections, intended to work for both new buildings and retrofit of existing frames. I led testing of 19 specimens across four full-scale beam-column subassemblies under the AISC Seismic Provisions’ cyclic loading protocol, plus monotonic push-up/pull-down tests on restored pre-Northridge welded-flange, bolted-web assemblies, to check whether the connection meets prequalification demands in both contexts rather than just one.

Nonstructural equipment often governs seismic risk independent of the building’s global response

Safety-related equipment in nuclear plants and floor-mounted components in hospitals can fail at accelerations the primary structure survives easily, so their risk depends on component-level dynamics – support flexibility, base isolation, tuned-mass damping – not just building-level demand. I modeled and correlated FEMs of electrical cabinets in ABAQUS and OpenSees against measured modal behavior, then ran NLTHA across isolation and damping designs to quantify the resulting risk reduction, and separately built a database of dynamic properties for vibration-isolated and rigidly-fixed components from AC156 qualification testing reports.

Full-scale system identification catches as-built behavior a design-stage model can’t

As-designed models routinely diverge from as-built dynamic behavior in ways only full-scale, non-destructive testing surfaces. On a three-story steel testbed building at UCSD’s outdoor shake table, I planned and instrumented the sensor network, then used impact and multi-directional white-noise tests to identify system properties and validate the FEM and analytical model against them – the same approach I used at smaller scale on a nonstructural component mounted with flexible connections.