Development of an image processing model for the measurement of vibrations in structural elements by matlab and smartphone digital camera

Abstract

As a practical and competent instrument for quantitative deformation measurement of a structural element, digital image correlation (DIC) is nowadays widely accepted and commonly practiced in the area of structural dynamics, however most of the existing methods rely on expensive devices and require complicated laboratory setup. The aim of this research is to develop a cost-effective model to measure dynamic vibrational displacements of a structure by using digital close-range photogrammetry technique. The main advantage of this model is the simplicity and rapid measurement of vibration using a low-cost smartphone digital camera, and vibrations of non-accessible facilities such as radioactive or high temperature components may be monitored remotely by using this method. The method is based upon obtaining the consecutive stereo images of the vibrating structure with multiple target marks and subsequently developing a programming tool to analyze vibrational displacements of the structure using a simple photogrammetric method with the use of Smartphone Digital Camera technology and MATLAB software. It is found that the proposed model gives good agreement when compared with vibration measurement using expensive High Frame Rate Digital Camera.