Development of Economical Shake Table with Brushed DC Motor and Proportional-Derivative Control

Earthquakes pose a significant threat to cities worldwide, necessitating the development of effective and affordable methods to evaluate structural performance under dynamic loading. Although large-scale shake table testing of full structures offers the most accurate approach, the high costs involved make it impractical for many, especially research institutions in developing countries. This study addresses this limitation by developing an affordable, single-degree-of-freedom shake table. The developed shake table is displacement-controlled with a payload capacity of 200 kg, offering a practical solution for testing scaled-down models of real structures. It is powered by a brushed DC motor, which is widely available in developing regions, and utilizes a modified proportional-derivative (PD) control algorithm to simulate both harmonic and real earthquake motions. Using this design, displacements up to +/- 150 mm and accelerations up to 1g were achieved with acceptable error margins. This paper provides a comprehensive explanation of the shake table's mechanical design, control algorithm, hardware components, and user interface. It also presents comparisons between theoretical and experimental displacements and accelerations for sine wave and earthquake simulations under various payloads. The results highlight the effectiveness of this low-cost shake table as a viable tool for seismic testing, expanding access to critical structural evaluation in resource-limited settings.