Rocking of rigid blocks standing on a horizontally-moving compliant base

Abstract

In this paper the dynamic response of rectangular rigid blocks standing on a horizontally-moving compliant base that is not rigidly connected to its excitation source is investigated for the first time through a combination of analytical, numerical and experimental studies. A novel model combining the well-established studies of a rigid block supported by horizontally-moving rigid base and recent advances on the dynamics of a block rocking on compliant surfaces is derived. Specifically, the impact between the block and the moving base is modelled through a series of springs in parallel with dampers, leading to the generally known Winkler and Hunt–Crossley models. Model parameters are calibrated through forced harmonic rocking tests and then validated through extensive experimental tests with both free and forced rocking. Comparisons of numerically determined trajectories versus those experimentally determined highlight the accuracy of the compliant base model. The main advantage of the compliant base model over the traditionally adopted rigid base model is that it can better predict when rocking will be initiated. This feature is further highlighted from overturning charts numerically evaluated and experimentally verified.