Building stronger homes

FOR those living in Northern Australia, the threat of cyclones and extreme weather events remains ever-present.

But researchers at James Cook University’s Cyclone Testing Station are helping the building industry improve the resilience of households, thanks to their innovative wind-driven debris simulator (WDDS) at JCU’S Bebegu Yumba Campus in Townsville.

Developed as a pressurised cylinder that can project debris objects at velocities in the order of 50 metres per second, the WDDS has been in continued development and operation for at least 20 years.

Station senior engineer Simon Ingham said the simulator was vital to test the effects of wind forces on buildings and components to ensure they comply with ever-tightening

Australian Standards.

“It’s very important to do this debris testing if people are going to use these items to protect themselves within a house,” he said.

“We produce specific test reports that show how we tested these items and the criteria is also extremely important for cyclone shelters and places of refuge.

“If a manufacturer needs to know if their item is debris resistant, or if they’ve been asked to provide debris resistance for a product, they can refer to our technical notes to get a better

understanding of the requirements that are needed for that product.”

Mr Ingham said Australian Standards-rated timber and steel debris items could be projected by the simulator, while ice was used to simulate the impact of hail on a building.

“We use 4kg hardwood timber debris items which simulates an old rafter from a house that has been blown apart,” he said. “The steel ball bearings that we use are 8mm in diameter, which simulates gravel.”

The simulator team calculates what speed to project objects based on a percentage of the region’s wind velocity.

“For example, in Townsville we would have timber debris projected by the simulator at velocities upwards of a 100 kilometres per hour,” Mr Ingham said. “That gets projected into any building project that requires debris resistance to be analysed, such as a debris screen on a window or door.”

Assisting the simulator is a large upright frame with a catch wall where a window, debris screen or wall can be attached in order for debris to be projected against it at different impact points to assess all vulnerable areas.

While the CTS isn’t the only location that conducts simulated debris testing, Mr Ingham said the Station plays a vital role in developing Australian Building Standards. Part of that includes continuously upgrading the simulator to ensure it can continue replicating realistic high wind damage scenarios.

“The CTS is the only facility in North Queensland that does this kind of testing and we have people from all over Australia and overseas, such as Fiji and the Pacific Islands, who are continuously sending us products to test. Without this facility and the simulator, the building industry would not be able to say they comply with Australian Standards for debris impact resistance.”