vPERFORM: The Development of Footfall Loading Models for Human Walking on Vibrating Surfaces

The design for 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. The 2-year project, vPERFORM, aims to identify vertical vibration conditions under which the human-structure interaction occurs and model the interaction to reflect experimental observations of human walking on a vibrating structure. Experiments were carried out in a state-of-the-art facility, VSimulators, to investigate the influence of vibration amplitude, frequency and exposure time on the interaction during normal walking on a treadmill placed on a vibrating platform. Fifteen test subjects were recruited, and ground reaction forces and kinematics data were recorded using force plates and motion capture systems, respectively. In addition, the metabolic cost was also measured to clarify the role of energy optimization in human walking in a vibrating environment. This paper presents details of the experimental program as well as selected preliminary results on ground reaction forces of human walking on the vibrating platform.