Piezoelectric Shaker for Simulating Earthquakes

Abstract

A centrifuge can theoretically simulate gravity-induced stress on earthen structures at a reduced geometric scale through centrifuge loading. These scaling laws show the usefulness of the centrifuge to test large structures of a size that cannot be tested practically in any other fashion. Seven possible shaker designs were considered. The paper presents a description of the piezoelectric shaker chosen and its development for a 5-g ton capacity centrifuge. A piezoelectric material deforms when subjected to an electric field and this principle was used to drive the shaker. The prototype tests showed the feasibility of simulating and controlling an earthquake motion by using the piezoelectric system, the presence of mechanical resonance at some operating frequencies, and the decline of acceleration produced by the piezoelectric system with increasing rpm. This system shows promise for adaption to a larger payload system.