Fillet and partial penetration butt welds

Designing economical welds that can be easily fabricated and inspected is very important to improve the productivity and efficiency of steel construction.

Fillet and partial (incomplete) penetration butt welds are often the most cost-effective for seismic- resisting systems, yet misconceptions persist about their performance under seismic loads. In fact, many design specifications still call for complete penetration butt welds to be used in seismic full- capacity connections.

Our collaborative research with leading universities, including Auckland, Waikato, AUT, and Michigan, aims to demonstrate that the current sizing criteria for fillet welds in NZS 3404 are conservative. We also are exploring the potential of partial penetration welds as viable alternatives.

Earthquake resistant buildings

We are collaborating on the “Sustainable Earthquake Resilient Buildings for a Better Future” five year research program led by AUT and funded by MBIE’s Endeavour Fund.

The main objective of this project is to optimise the benefits of friction sliding systems in earthquake resistant buildings by developing reliable, cost-effective, and adaptable friction sliding systems for buildings subjected to severe earthquakes and fires following an earthquake.

ROBUST building systems

In collaboration with nine other sponsors both nationally and in China, as well as many other material and in-kind support and expertise, this research involves testing of three-storey 9m tall, 8.5m x 5m plan friction structures on a large shaking table to understand their responsiveness in seismic events.

Friction within the connections dissipates the earthquake energy entering the structure. This is different from conventional systems, which generally rely on the yielding of steel. Here, the shaking elements damaged by yielding likely need replacement. With frictional structures, the building can be reinstated with much less effort and cost.

Optimised sliding hinge joint

Low-damage seismic solutions not only improve building resilience and occupants’ safety in a seismic event, but also have a significant role in facilitating structural steel reuse after severe earthquakes.

Additionally, the OSHJ provides a low-damage, highly seismic resilient, versatile, and cost-effective seismic resisting connection option primarily for Moment Resisting Steel Framed (MRSF) buildings to structural engineers.

Overall, developing this report is important in helping practicing structural engineers in Aotearoa to confidently design and install OSHJ’s in their projects.