Application of acrylic plates as load cell for detecting strain and force in structures

Abstract

This study presents the use of two superimposed transparent acrylic plates as a load cell for strain and force measurement. The gap between the plates behaves like an interferometer. When a monochromatic light beam is incident upon the gap, it interacts with the two air-acrylic interfaces, causing constructive and destructive interference. This phenomenon results in the formation of an interference pattern. Interferometers are devices used for high-precision measurements. In this work, the strain and force applied to an aluminum bar were precisely measured using two acrylic plates fixed to the bar. The experiments showed that the proposed method has a measurement range of 0–60 $\mu \epsilon$ and a resolution of 0.27 $\mu \epsilon$ . It is demonstrated that the proposed method offers a low-cost strain measurement technique with a wider measurement range compared to fiber optic sensors