###Vibration and stability of slender structures under moving masses
Project ID: 2228bd1125 (You will need this ID for your application)
Research Theme: Engineering
UCL Lead department: Civil, Environmental and Geomatic Engineering (CEGE)
Lead Supervisor: Gert van der Heijden
Project Summary:
Masses moving along slender structures are encountered in many engineering contexts: road and railway bridges, cableways, robotic arms, pipelines carrying fluids, etc. Deformations due to moving loads/masses are also intentionally induced in structural health monitoring. Identification of structural damage (such as cracks) often relies on vibrational data that contain information about the damage. For high-quality experimental data moving devices (inspection robots) are employed to excite relatively large amplitude vibrations of the structure.
Given this wide importance it is perhaps surprising that the fundamental mechanics of the moving mass problem is still not fully understood. This is highlighted by the Timoshenko paradox: a simply-supported beam carrying a moving mass, even though initially at rest, will keep vibrating after the mass has left the beam, despite the fact that its weight will have done no work as the mass entered and left the beam at the same height. Where has the energy come from? Although the resolution of this paradox is now widely understood physically (linear theory ignores the horizontal force component, which does do work), there is still no complete quantitative theory. Paradoxical situations will keep coming up until a theory has been formulated that takes into account the proper two-way coupling between beam (or cable) and mass, in which the mass also responds to the motion of the structure. The aim of this project is to build this theory.
Having a complete theory we will develop quantitative models that take into account effects that have so far eluded researchers using traditional linear planar beam models, e.g., three-dimensional deformations (including out-of-plane instabilities and collapse), horizontally curved bridges, torsion, horizontal seismic loading, multiple (possibly colliding) masses, lift-off of the mass from the structure, extension to 2D structures (plates/shells).