An affordable displacement measurement tool for structural health monitoring

Displacement measurement is known to be one of the most important parameters of seismic load analysis. Despite the importance of displacement measurement, existing displacement measurement tools are incorporated with several constraints. Most of the existing tools are expensive, complex in structure, offers a small range and is not adjustable in small structural models. In this work, a Micro Controller Unit (MCU) and ultrasonic sensor based displacement measurement tool has been introduced, where the sensors are placed on the body of a multi degree of freedom (MDOF) steel structure model. Further, it calculates the relative displacement by calculating the displacement of multiple points from a fixed reflection surface. The proposed tool is able to measure the displacements that lie to a range of 1000 mm and occurs due to a seismic load at El Centro earthquake ground motion. Moreover, the proposed tool demonstrates a consistent accuracy compared to a hand engineered analog displacement measurement tool.