Modal testing with a pedestrian as a vibration exciter

Abstract

A novel approach, for identification of modal properties using a dynamic excitation induced by a human walker, has previously been proposed to identify natural frequencies, damping ratios and modal masses. The developed approach is now expanded to also estimate vibration mode shapes, thus fully characterising the dynamic behaviour of a structure in a simple and affordable way. Additionally, the reliability of the method is parametrically analysed and validated against simulated and real world data of a footbridge. Results indicate that, given a reasonable initial estimate of the target modal properties values and with careful consideration of the number and location of measured responses, it is possible to estimate all modal properties of a structure in a reliable and simpler way than conventional modal testing methods: handheld impact hammer, electrodynamic shaker or ambient vibration tests.