vPERFORM · Developing advanced vibration performance assessment for new generation of lightweight pedestrian structures using motion platform and virtual reality environments

Developing advanced vibration performance assessment for new generation of lightweight pedestrian structures using motion platform and virtual reality environments

An ever-increasing use of building materials with high strength-to-weight ratios has led to development of slender and lightweight structures with dazzling structural forms, especially in case of landmark public structures such as footbridges, walkways and corridors between buildings, at airports and shopping centres. Such a trend is fuelled by the urgent need to improve sustainability through minimising use of materials in construction. It follows that structures are more sensitive to human-generated dynamic loading than ever before and their design is largely governed by vibration serviceability limit state. Assessment of structural vibration induced by human walking is currently based on loading models obtained on rigid surfaces. It is largely unknown how footstep forces would be modified due to human-structure interaction if the surfaces are vibrating. Pedestrians start interacting with vibrating structures under certain and still largely unknown conditions resulting in vibration-dependent dynamic force and unacceptably large errors in predictions of the actual vibration response. This has a serious consequence in misclassification of the bridge as being on the brink of “unacceptable structure” instead of being classified in a more favourable category of “providing mean comfort”. In a climate of fast urbanisation, only if we develop understanding of how people interact with vibrating supporting surfaces, we will be able to satisfy demand for vibration serviceable structures at minimum cost and material use and then achieve net-zero carbon emissions. The project, vPERFORM, aims to transform the current design practice by developing reliable predictive models of vibration performance of lightweight pedestrian structures and for the first time to establish how vertical vibration influences pedestrian walking and resulting dynamic force. Human walking behaviours and ground reaction forces on vibrating surfaces are being examined to reveal the influence of the platform-to-human component of the human-structure dynamic interaction. The output of vPERFORM will advance vibration serviceability design methods for pedestrian structures to replace the existing oversimplified approach to vibration assessment, pave the way for the adoption of high strength-weight ratio materials such as timber, and finally make structures more serviceable and greener.

Data: CORDIS, © European Union