We are not limited in our scope to building systems composed only of cold-formed steel, but are interested in solutions that use the appropriate building materials, whether it be for sustainability or affordability issues. Our research includes modern methods of construction, such as FRP or 3D printed concrete, with cold-formed steel used for the roof truss, cladding, lintels etc.
We use a combination of experimental field tests, smaller-scale laboratory tests, finite element analysis, machine learning and optimisation to understand the structural behaviour, environmental / sustainability issues related to the use of cold-formed steel. We have a smart digital laboratory and are interested in Construction 4.0, VR/AR, BIM where appropriate to cold-formed steel construction.
In New Zealand, we have attracted support from industry of more than $2 million dollars to support post-docs, PhD students and experimental tests. We have published around 200 journal papers.
Our research comprises full-scale testing and finite element modeling to understand the behavior of portal frames. This includes framing and joints as well as the influence of stressed-skin diaphragm action.
During strong wind occurrences, cold-formed steel (CFS) roof claddings are exposed to severe suction/uplift forces. In regions where the prevailing winds are strong, such as New Zealand. The turbulence of the wind flow around the building generates suction pressures, which vary both spatially and temporally. According to observations, the weakest link in the roofing system is the connection between the roof sheeting and the screw fasteners, which, if they break, may lead to progressive roof loss. High wind suction pressure fluctuations may cause static or fatigue pull-through failure of the roof sheeting at its screw fastener connections.
As a result, our team has done considerable research on full-scale tests and finite element modelling of roofing and cladding systems subjected to static and constant amplitude cyclic wind loading.
FRP wall panels
We have recently signed an MOU with Affordable Housing Ltd, a construction company and the developer and provider of SAIMU FRP structural wall panel building system in Hamilton, to improve further understanding and conduct ongoing research and development on the structural behavior of their innovative Fibre Reinforced Polymer (FRP) wall building systems, concerning structural strength, seismic behavior, durability and fire resistance for residential and commercial buildings in New Zealand and possibly countries in the pacific rim.
There is a lack of understanding on the behaviour of cold-formed steel structures subject to fire. For the case of single storey buildings, our team has led the experimental testing to collapse of two such buildings in collaboration with Professor Lau of Swinburne University.
Beams and Columns with Openings
Openings for service integration are very important for cold-formed steel construction. There is often a lack of guidance in the codes and standards. Our team investigates using a combination of experimental testing and finite element modeling to understand the effect of openings. We have found that the used of edge stiffened openings can sometimes increase the strength beyond that of sections without openings e.g. in the case of web crippling.
At the requested of industry, we have used optimisation techniques to investigate potential cost and material savings in steel framed buildings. These can be up to 30% for both tapered sections portal frames as well as cold-formed steel portal frames.
While our group primarily focuses on providing solutions for the building and construction industries to tackle research and commercial engineering challenges, we also use our experience in artificial intelligence to study and evaluate the structural behavior of structural systems. Currently, we are investigating the following areas:
- Massive database for structural analysis system;
- Effective machine-learning tool for structural analysis;
- Intelligent building design;
- Artificial intelligence in sustainability.