Structural Health Monitoring of Rotating Structures Using a Mobile Digital Image Correlation Platform

Digital Image Correlation has proven itself to be a highly versatile and accurate method to measure 2D and 3D displacement, deformation, and strain in a wide range of structures. A major advantage of this technology is that it is a non-contact, full-field measurement technique; it measures phenomena across the entire target without having to attach sensors directly to the object. Despite the ability to measure many static and dynamic phenomena, the cameras and data acquisition equipment are almost exclusively set up using a traditional static configuration. The cameras are often mounted on tripods and remain positioned in the same location while taking measurements. Such an immobile measurement platform prevents DIC from being employed to measure rotating structures during operation due to accessibility restraints. An unmanned aerial vehicle carrying digital image correlation cameras has high mobility and can easily access the regions on structures that would otherwise be too expensive or dangerous to measure with conventional static camera setups. This paper presents the development and testing of a prototype mobile digital image correlation platform. The resulting platform carries all of the necessary equipment on-board the drone and can be controlled by a single user with a remote control. It is shown that the prototype drone platform is capable of taking accurate and repeatable measurements while airborne. The current work is the first body of research that uses a DIC system mounted to a drone to perform vibration measurements and to collect operating data from a rotating structure