Photogrametric measurements of tape springs in bending

Abstract

A tape spring hinge is a tape curved along its width, which can be folded to be used to deploy structural elements in aeronautical applications. Tape springs are both simple and robust, and they are being increasingly used in designs of actuators to deploy, among other things, solar arrays in satellites. Due to their simplicity and low weight, traditional methods to study their behaviour when applying moments can be inconvenient. This report develops a series of easily accessible algorithms which allow the study of tape spring hinges through Photogrammetry and Digital Image Correlation calculations when purely bending the tape spring. By processing and treating images, 3D structures of the tape spring when bent can be recovered. The steps to carry out the experiment and the mathematics behind the process completed by the MATLAB algorithms are explained in this report.