Rig: Shake Table 2DOF

Version 1.00
Civil Engineering,

This rig has been replaced by version 1.1. The shake table rig models the behaviour of a building during an earthquake. The rig uses a simplified structure to model a 2-storey building (2 degrees of freedom), and the earthquake is simulated by linear base motion.

The rig consists of a 2-level building model where each storey is represented by a known mass. The levels are linked by pieces of spring steel with known stiffness coefficients. The model can be vibrated at the foundation using a motor with a scotch yoke, while the excitation frequency can be interactively selected by the student. The resulting displacement is measured by linear displacement sensors at each level and plotted in real-time on the user interface, and all data can be downloaded. The model may also be dynamically damped using eddy current damping, either in open loop mode or closed loop mode (PID control). Consequently, students can use the shake table rig to characterise a real, physical structure, to determine the amount of damping required at various frequencies and to effectively suppress vibration and resonance.