Executive Summary : | The global use of composite materials has grown rapidly from 158,800 metric tons/350 million lb in 1960 to 6.1 million metric tons/13.5 billion lb in 2004 representing 3,800 percent growth in the last 45 years. (Global Composites Market 2004-2010) The total worldwide turnover in 2016 amounts to approximately 2.34 billion US$, corresponding to a growth of 8,7% to the previous year. IIT Madras has significant expertise in the area of Ultrasonics based sensors and measurements, particularly in the area of composite material inspection. (References 19a-r) Dhvani Research and Development Solutions Pvt Ltd, Chennai, a mature IIT Madras incubated company, is leader in the area of development of NDT and Automated Inspection solutions with several products used by strategic sectors and industries. In this project, the automation, software and instrumentation expertise of Dhvani Research will be combined with the domain knowledge, theoretical and experimental capabilities of CNDE at IITM to explore and develop a new and novel ultrasonic inspection system for composite material based complex components. The system will be commercialized as a product by Dhvani Research and will provide the Indian Industries and its strategic sectors an affordable, serviceable, “state of the art” and indigenously designed and manufactured solution. The currently available ultrasonic C-scan methodology (which uses gantry robots, water based immersion mode, and conventional immersion transducers) will be significantly transformed by this work to the use of 6-axes industrial robots that manipulate air coupled transducers and provide both bulk and guided wave modes of inspection. Thereby, the capabilities and acceptability of ultrasonic inspection is expected to significantly increase while at the same time improving the quality assurance at reduced costs. The principle of operation of the air coupled guided wave ultrasonic approach involves the generation of the fundamental A0 mode that is sensitive to several defects and damage conditions in composite material components including delamination, disbond, and impacts. In addition, the guided ultrasonic waves travel and inspection large volume of the material thereby significantly increasing the speed of inspection by up to 2 orders of magnitude. Another key advantage of guided waves to follow complex shapes of the component allows for the inspection of normally un-inspectable regions, such as sharply curved regions, hidden inaccessible regions such as stiffeners, stringers, etc. from outside the component. The use of air coupled ultrasonic probes is another innovation that removes undesirable couplants. The use of 2 five axes robots operating is synchronous scanning mode permits the automation and scalablity to manufacturing and field in-service applications. The system will be commercialized for many composite material applications in aerospace, defense, space, power, transportation and infrastructure industries. |
