Speaker: Dr. N. Sujata
Chief Scientist & Head, Materials Science Division,
CSIR-NAL, Bangalore 560017, India
Abstract:
Statistics show that the most prominent mechanism of failure in aircraft structures and engines is fatigue. Important information about the failure process can be readily obtained from examination of the fracture surfaces of prematurely failed components, and these data often provide important inputs to the designer as well as the user for accurate estimation of component life and prevention of catastrophe. Since fatigue damage occurs due to cyclic loads, the characteristic features of the beach marks and the striation count within the progressive crack propagation zone of the fracture surfaces created during service failures or during ground tests provide information on the type of loading and also the time of initiation and the propagation of cracks.
In this talk, two examples of fatigue failures in aircraft components, one that occurred in service and the other that failed on the test bed will be discussed. The importance of failure analysis in structural integrity, with reference to understanding the failure process, the methodology to be adopted for estimation of the time of initiation of fatigue crack and its propagation will be highlighted from these two examples.
Bio-data of the speaker:
Dr. M. Sujata obtained her B.E in Metallurgical Engineering from Andhra University in the year 1989, and her M.Tech and Ph.D (Materials and Metallurgical Engineering) from IIT Kanpur in the years 1991 and 1996 respectively. She has been a Post-doctoral fellow at the Department of Materials Engineering, Indian Institute of Science during 1997-1999. Since 2002, Dr Sujata is at the Materials Science Division of CSIR-National Aerospace Laboratories (NAL), Bangalore. Currently, she is the head of Materials Science Division at CSIR-NAL. During the past 22 years, she has been working in the area of failure analysis and accident investigation and has investigated more than 750 in-service failures in aircraft engines/structures/systems. She and her team have been rendering yeomen service to the aero-space sectors of the country, namely, HAL, Defence services (Indian Airforce, Navy and Army aviation), certifying agencies and DRDO laboratories. Her team published several articles in national and international journals in this area. Prior to joining NAL, Dr Sujata served as Deputy Manager at the Foundry & Forge Division of Hindustan Aeronautics Limited, Bangalore during 1999-2002. She contributed to indigenization of materials for various aircraft programmes while at HAL.
Dr Sujata has been conferred with Young Metallurgist Award of the Year by Ministry of Steel and Indian Institute of Metals, in the year 2001. She has also been recognized as one of the Women who made Outstanding Contributions to Aerospace Sector in India during the AeroIndia 2019 exhibition, 20-24 February 2019, Bangalore.
Organized by:
InSIS and Center for Structural Integrity of Safety Critical Systems, IIT Madras
