A new method may improve the safety inspection techniques for structures such as buildings, aeroplanes, bridges and ships, a Sydney mechanical engineer says.
Ummul Baneen, of the University of New South Wales, has found a way to suppress the noise associated with damage detection techniques, allowing for better identification of unknown edge cracks and delaminations.
“Damage is often not visible and may grow to a serious degree without being obvious from the outside,” says Ummul, who did the research as part of her PhD.
“Noise in data measurements creates a detrimental effect on nearly all damage detection techniques. This can be reduced so that the useful information is not lost along with the noise,” she says.
Ummul used two beams of different materials, steel and glass fibre, and successfully localised multiple edge cracks as severe as 50 per cent and 2.5 per cent of the steel beam’s thickness. In the glass fibre beam she demonstrated the effectiveness of her method by detecting both narrow and wide delaminations.
“These results were achieved without using any reference data, which indicates its potential to be used for in-service structures,” Ummul says.
She used her noise suppression technique on two conventional vibration based damage (VBDD) methods. Unlike other damage evaluation methods, VBDD does not require prior knowledge of the damage location or comparison data from the structure before it was damaged. However, noise in the measurements can often interfere with the ability to accurately detect damage.