In November 2016, Rohan McElroy from i3 Consulting was selected to present at the European Composites in Construction (CompIC) conference held in Amsterdam at the end of January 2017. CompIC is a two-day conference bringing together industry professionals from all over Europe to have an open discussion with presentations regarding the state of the Composites industry and recent developments.
Rohan’s presentation addressed his research into the assessment of pedestrian-induced excitation performance of light weight FRP footbridges produced by Wagners Composite Fibre Technologies in Toowoomba. Currently there is no universally accepted procedure to address excitation design of footbridges in a variety of national design codes including: Australian Standards, Eurocode, UK National Annexure to Eurocode, British Standards and American Standards. Rohan found that each of these publications have their own method to assess excitation performance, but there was no correlation between results that could be used to responsibly certify a single structure.
Rohan’s research covered important University findings ranging from 1977 to 2005 along with the increased interest in excitation design since the opening of London’s Millennium Bridge in 2001. The culmination of his findings resulted in a method of accurately assessing pedestrian induced excitation using Strand7 Finite Element Analysis software and was cross-compared with in-situ excitation performance of an in-service footbridge. The in-service footbridge was subjected to groups of icubed’s team walking across in time to reflect the FEA modelling undertaken. A number of android smartphones were placed on the bridge deck and accelerometer apps were used to measure deck excitation. The output data from these apps was then compared against charted data from the Strand7 FEA outputs with data lining up fairly consistently.
Rohan’s presentation was well received by the audience with quite a number of industry professionals requesting further information about the procedure and providing some insight into issues they have come across. icubed are also looking into the effect of wind-induced excitation on FRP footbridges as this is also an area of concern which is only partially covered by national standards codes. Research into wind-induced excitation is heavily reliant on computational fluid dynamic software and is a complicated research topic.