Overview of Aerospace Structures Research in India

This paper provides an overview of research in Aerospace structures in India by premier academic institutions and research laboratories. The research programs have been closely influenced by the aerospace flight vehicle programs in India. Research funding was available based on the design requirements and the Indian researchers covered a wade spectrum of research areas. The major sponsor of aerospace structures research has been Aeronautics R&D Board and in space related research the major sponsor has been Indian Space Research organization. This paper highlights some of the major contributions. Aerospace Structures research in India has been supported at the premier academic Institutions covering Indian Institute of Science (IISc), Indian Institutes of Technology (IITs) at Chennai, Mumbai, Kanpur and Kharagpur, and also the Departments of Aerospace Engineering and Madras Institute of Technology, Anna University among several other universities. Within these academic institutions, individual engineering departments like Aerospace, Mechanical and Civil have contributed to the overall development. Among the Research laboratories, the CSIR Laboratories had extensive sponsored R&D projects with the maximum interaction with National Aerospace Laboratories (NAL), Bangalore, and Structural Research Engineering Center (SERC), Chennai. The major organization which sponsored the projects has been Aeronautics R&D Board. The design and production agencies have also sponsored their project/need based R&D from time to time. In all, quite a significant work of a high caliber was carried out in the past four decades and the results are extensively published in open literature. This paper presents a review of certain parts of the work which is primarily published and help built a broad theme of research behind the ongoing and recently initiated programs. The research reviewed presented here can be divided into the followings: 1. Structural Integrity studies covering Fracture Mechanics, Joints and Non-Destructive Testing 2. Composite Structures including analytical and manufacturing methods 3. Computational Structural Mechanics primarily covering Finite Element Methods 4. Broad spectrum of topics covering Impact Mechanics, Patch Repairs, interface cracks etc. These are the areas covered under structures with wide coverage on Structural Dynamics, Materials Engineering, Structural health Monitoring and Rotor Dynamics which are reported elsewhere. The work is generally coordinated by a large monitoring committee which encourages Scientists to initiate new areas, phase out well researched topics and take up challenging fields at the frontiers of science. The authors compiled as much as they could collect and put together in the time available within the time constraints of the scientists in various institutions. II. Fracture Mechanics and NDT Studies A major effort at the Indian Institute of Science (IISc), Bangalore resulted in fatigue and fracture software including crack initiation and crack growth phases. Besides the fatigue analysis based on stress- and strain- life approaches, the program utilized special methods developed for estimation of strain-energy-release rates for crack growth analysis. Modified Virtual Crack Closure Integral (MVCCI) technique was developed for regular and singular two- and three- dimension finite element analysis of cracked domains. This has been integrated with the software and applications of this software extended to de-laminations in composites, cracks around riveted and bolted joints and