1979-1984

Scientist – C

NAL, Bangalore

1984-1986

Scientist – E1

NAL, Bangalore

1986-1990

Scientist - E, (Deputy Proj Dir)

Aero Dev Agency ( ADA ), Bangalore

1990-1994

Scientist - F (Deputy Proj Dir)

ADA , Bangalore

Nature of

A

National Aeronautical Laboratory (NAL), Bangalore (1974-86)

Technical

(Now, National Aerospace Laboratories)

Work

A1

ASLV Transonic Buffet Studies: Aeroelastic Model Design and Testing (Project Leader)-VSSC, Trivandrum Sponsored Project

• Innovative design of model and support system to simulate free flight condition
• Use FRP in model design
• Predicted dynamic bending moments due to transonic buffet response to help clear launch vehicle design from buffet considerations
• Such a study was carried out for the first time in India
• The work has set the standard for subsequent studies on ISRO designed launch vehicles at NAL such as PSLV & GSLV

A2

Analysis of Axi-symmetric Composite Shell Structures for Asymmetric Wind Loads (Project Leader)-DRDL, Hyderabad Sponsored Project

• Finite element study using axi-symmetric shell elements - Fourier series representation of wind loads - Software developed for modelling and analysis

A3

Design of Sandwich Bridge Deck Plates and Filler Panels (Project Leader) -R&D Engineers, Pune(DRDO) Sponsored Project

• Design with honeycomb core, GFRP facings and edge members, film and foaming adhesives, autoclave curing planned
• Substantial weight savings over metallic structures predicted

A4

R & D Studies on Aeroelasticity ( Project Leader)

• Initiated studies on aeroelastic tailoring using advanced composites and active flutter suppression

B

Aeronautical Development Agency (1986 - 2004)

ADA has been entrusted by the Government with the responsibility for the development the Light Combat aircraft(LCA) . LCA is a state-of-the-art, single-engine, multi-role, light weight, high agility combat aircraft that employs several advanced technologies such as an aerodynamically unstable configuration, an airframe built predominantly out of carbon fibre composites(nearly 45% by weight) and a fly-by-wire flight control system with a digital FCC and fast responding actuators, advanced avionics etc.

• Aeroelasticity and Structural Dynamics play an important role in the design and need to be considered in the design stage itself unlike in earlier generation aircraft
• Aeroelasticity has significant effect on aerodynamic load distributions which in turn modifies critical design loads and control law design
• Composites permit aeroelastic tailoring concepts to be used in optimisation of wings and fin leading to significant weight savings
• Aeroservoelasticity (structure-control-aerodynamics coupling) is a design driver for the control system. Analysis and full aircraft tests are milestones in the airworthiness clearance route
• Damage tolerance considerations play a significant role in composites design and considerable efforts to characterise the same through analysis/tests is called for.
• Composites usage also calls for extensive tests at coupons, features and box levels to generate design data and/or validate design concepts. Design and fabrication of test boxes to exacting standards is a major activity
• Major emphasis on indigenisation has resulted in efforts to develop metallic/non metallic materials and processes including adhesives, sealants, prepregs etc.
• Flight tests for loads, flutter clearance , vibration etc are major activities calling detailed planning in advance.

The officer held overall responsibility for majority of the above tasks in the LCA Project in his capacity as

Head,Structural Dynamics and Aeroelasticity Group, Airframe Directorate: (1986-1994)

Group Director, Structural Technology, Airframe directorate: (1994-2000)

Project Director,Structural Technology Directorate: (2000 onwards )

B1

Loads, Dynamics and Aeroelasticity

1. LCA Manoeuvre Load Computations

• Work involved synthesis of full aircraft aerodynamic loads(CFD,WT) , Full aircraft finite element model with inertial loads and consideration of aeroelasticity effects on load distributions
• Critical load cases selected for structural optimisation and design from over 1000 manoeuver load cases computed to cover critical regions in flight envelope
• Input to FCS designers on aeroelastic efficiencies on rigid aircraft data

1. Structural Optimisation Studies

• Preliminary optimisation of CFC wing skins for minimum weight with stress, buckling, aeroelasticity and technological constraints
• Evaluation of merits of candidate materials and build concepts as an input for detailed studies

1. Free Vibration Analysis

• Computation of free vibration modes and frequencies for various aircraft configurations using finite element models

1. Flutter Analysis

• Conventional open-loop flutter analysis in subsonic and supersonic domains and proof of necessary margins
• Flutter analysis with FCS feedback loops closed to assess the impact of FCS on flutter
• Aeroelastic model test in wind tunnel at transonic speeds

1. Aeroservoelastic Analysis

• Established a methodology for aero-servo-elastic modelling and analysis involving structural dynamics, unsteady-aerodynamics and control system dynamics components--important for FBW aircraft
• Frequency domain analysis to predict aircraft motion sensor responses to primary control surface excitation
• Provided inputs to FCS Designers for Notch Filter design

1. Ground Vibration Tests on Aircraft

• First major test in the LCA integration programme
• Generated full aircraft modal characteristics experimentally to verify / supplement analytical prediction
• Random excitation technique used for the first time in the country in a major vibration test programme, leading to shorter test duration and lower excitation levels on aircraft

1. Structure-Control Coupling Tests on Aircraft

• Second major test in the LCA integration programme
• Complex tests on aircraft to extract aircraft motion sensor response for primary control surface excitation through the FCS-highly interdisciplinary in nature
• Open loop tests for aircraft identification and closed loop tests for notch filter adequacy verification
• Involved unique test system development, detailed and careful planning, aircraft load monitoring from safety considerations etc
• Generated design data and proof of design adequacy for flight clearance
• First time in the country on a large aircraft

1. Flight Flutter Tests

• For the first time in the history of flutter testing in the country, flutter excitation through control surfaces using the FCS
• Planned near- real- time analysis of data to reduce the number of test flights required significantly
• Established a state- of –the –art test and analysis system
• Carried out extensive flight flutter tests in transonic and supersonic regimes as a part of flight envelope expansion.

1. Software Development

• Initiated development of software at IIT, Bombay for static and dynamic aeroelastic and loads analysis to be integrated into an indigenous FEM based general purpose structural analysis software; SW undergoing evaluation at ADA

B2

Composite Materials Technology

Directing activities of Composites Group such as Material Characterisation and Testing, Features Tests, Damage Tolerance Studies, Fatigue & Fracture Studies, Indigenous Materials & Processes Development (non-metallic) through in-house work and sponsored projects , leading to

• Specification and validation of design allowables
• Generation of criterion for allowable damage limits in composites design
• Assistance to flight clearance of composite parts
• Development of adhesives, films, sealants for immediate use on aircraft
• Study of impact behaviour on windshields through coupled non-linear analysis and testing
• Setting up of pilot plant at NAL, Bangalore on a Rs 20 crore project of DRDO and ADA for manufacture of precursor, carbon fibres and prepregs – self sufficiency in strategic materials and technology

B3

Composites Fabrication Technology

Directing activities of Composites Fabrication Technology Group such as Fabrication and Assembly of complex Test Boxes for LCA structural design concept verification, Fabrication of test rigs for testing of these test boxes, Fabrication / assembly of LCA structural components such as undercarriage bay-doors, Expertise in novel fabrication processes such as RTM and autoclave moulding, Indigenous development of autoclave consumable materials as a replacement for expensive imported items etc.

• The Group has a major project from GTRE, Bangalore for development of some Kaveri Engine Components in Composites for service temperatures of around 300 deg C ; calls for polyimide resins development and processing, design and development of bypass duct, nozzle flaps, and nose cone; significant weight savings predicted; nozzle flaps and nose cone delivered.
• Moderate facilities for fabrication have been set up at GTRE and ADA

B4

Smart Technology Activity

Smart materials and structures has attracted a lot of attention in the last six to ten years as a technology with great potential for exploitation in the aerospace field. Considerable research effort is being focussed in the developed countries on smart sensors and actuators and their application technologies in various fields. Realizing the potential of smart technology for the Indian aerospace programme and the fact that research efforts elsewhere were still in an exploratory phase, it was felt that a major national effort was required to be launched in India for the country to be recognised as a major player in the field.

1. National Programme on Smart Materials(NPSM)

Programme Director of the National Programme on Smart Materials (NPSM), launched jointly by five Govt Departments, namely, DRDO,CSIR,DOS,DST and MIT in the year 2000, overseeing its management and administration through the programme cell at ADA . NPSM is a 5 year programme with a budget of Rs 75 Crores. The Programme has identified the areas of interest (aerospace, bio-medical), defined specifications of the technology to be developed and the technology management procedures. It has initiated nearly forty R&D projects in the area of smart materials, sensors & actuators and MEMS in institutions of repute. It has also provided for the setting up of national facilities for MEMS design, fabrication and packaging. Some of the projects are reaching successful conclusion leading to usable devices and technologies. Actively participated in the DRDO-ISSS-Industry Meet on MEMS in 2002 and subsequently nominated to the Task Force set up by SA to RM to progress Industry interaction. An Interactive workshop was successfully organised in March 2004 to promote user department/industry involvement. The programme has acted as a catalyst and model for several independent initiatives in micro- and nano- technology area.

2. Development Initiative for Smart Aircraft Structure(DISMAS)

Parallel efforts at developing technologies for application of smart structural concepts in aircraft have been initiated at ADA through a Rs 20-crore, five year project, DISMAS. The project aims at demonstrating applications of smart structures on actual structures in three major application areas in which work is in progress, namely,

• Noise and Vibration Control
• Active Shape Control and
• Structural Health Monitoring

Ten projects in progress involving wave based and fibre optic based health monitoring, aerodynamic surface actuation using SMA, vortex flow control, vibration and flutter control in wing like structures, on-board smart vibration sensing and actuation system, fibre optic sensors and associated opto-electronic system development, smart pressure sensor for aerodynamic pressure monitoring etc.

3. India–Trento ( Italy ) Joint Programme of R&D Cooperation (DST & Govt of Italy )

Organised a DST sponsored workshop to identify specific projects of mutual interest in Microsystems, Telecommunications, Computer Science and Physics/materials, leading eventually to signing of cooperation agreement and sanctioning of one project in each area to Indian institutions; Indian Coordinator for Microsystems area under the overall technical coordination of Dr Kota Harinarayana, VC , Univ of Hyderabad from the Indian side. Two coordination meetings held so far, the first in Trento and the second in Hyderabad .

Professional Memberships

• Fellow, Aeronautical Society of India

• Founder Life Member, Indian Society for Advancement of Materials and Process Engineering (ISAMPE)

• Life Member, Institute of Smart Structures and Systems (ISSS)

• Member, Semiconductor Society of India

Allied Professional Activities

• Member Secretary, Divisional Advisory Committee and Divisional Scientific Committee, Structures Division, NAL (1982-86)
• Member, Divisional Scientific Committee, Structures Division, NAL (1994 -)
• Member Secretary, Board for Smart Materials Research and Technology, chaired by Dr V K Aatre, SA to RM
• Member Secretary, Expert Committee on Aeronautics: Structural Design and Analysis, Chaired by Dr Kota Harinarayana, the then Programme Director, ADA as a part of the DATE(Decision Aid for Technology Evaluation) Committee of DRDO headed by Dr VK Aatre, Director General, DRDO
• Secretary, Programme Committee and Organising Committee, International Conference on Smart Materials, Structures and Systems, July 1999 at IISc.
• Member, FINESSE Software Development Task Force
• President (2001-2003), Indian Society for Advancement of Materials and Process Engineering. Served earlier as Jt Secretary, Secretary and Vice President of the Society. Currently, Member, ISAMPE Board.
• Treasurer (2001-2003), Institute of Smart Structures and Systems, Bangalore ; served earlier on its Executive Committee as a member, Currently, EC Member.
• Member, Executive Council, Aeronautical Society of India (2000-2001) & Member, Ex. Board, AeSI Bangalore Chapter(2001-2002)
• Member, Editorial Board, Journal of Aeronautical Society of India
• Member, AR&DB Structures Panel (2001-); earlier Rep in the Panel
• Participated in the AGNI failure review meetings at DRDL, Hyderabad , 1992
• Member, CDR Committee for FCS of AKASH, DRDL, Hyderabad , 1992
• Member of the Design Review Committee (Loads & Aeroelasticity) of Hansa Aircraft, NAL, Bangalore
• Specialist consultant for SARAS Aircraft Project for NAL, Bangalore
• Member, Review Committee for GSLV Aeroelastic Testing at NAL
• Member, Selection Committee for Scientists at NAL, IISc, ISRO
• Examiner, Ph.D & M.Tech Thesis at IIT, Bombay , IISc, Bangalore , Mangalore University
• Chairman/ Member , Review Committees to Review Project Proposals on MEMS/ Smart Structures at ADE-Bangalore, VSSC-Trivandrum, RCI-Hyderabad etc
• Member, CASDE Systems Engineering Syllabus Committee, IIT, Bombay
• Member, MDO Special Interest Group, CASDE, IIT-Bombay
• Chairman, Empowered Committee for organising the Ceremony for Naming of LCA by the Honorable Prime Minister on 4 th May 2003 .
• Convenor, Task Team set up by SA to RM to study Quality Assurance and Delays in LCA Programme and recommend solutions; some of the recommendations have led to improved efficiency
• Prepared a video film on Enabling Technologies from LCA programme (long and short versions separately) for the occasion of LCA first flight.
• Member, SARAS Flight Readiness Review Board, NAL, Bangalore
• Invited to participate in a meeting on nano- technology initiatives chaired by Dr Chidambaram, PSA to Govt of India, 2003 and in National Brainstorming Workshop on Nano Technology Initiatives by the Ministry of Commerce and Industry
• at CMTI, Bangalore , March 2004
• Jointly prepared a National Initiative on Micro/mini Air Vehicles(MAVs) with Lt Gen (Dr) V J Sundaram , Chairman, NDRF, Institution of Engineers for the consideration of DRDO.

Community Activities

• Chairman , Canteen Advisory Committee, ADA (1996-1999)
• Chairman, Security Review Committee, ADA
• Chairman, ADA Employees Welfare Association (1999- 2003)
• Vice President , Kasturinagar Resident’s Welfare Association(1998-2001), currently Member, Executive Committee
• Member, Board of Directors, Kasturinagar Recreation Club (1996-1998)
• Chairman, Solid Waste Management Committee, Kasturinagar (1998-2001)

Honours and Awards

• National Merit Scholarship Award for Under-Graduate Studies based on SSLC performance, 1966
• Roll of Honour(1 st in Class) in ME Degree Course, Dept of Aeronautical Eng, IISc, Bangalore , 1974
• Commonwealth Fellowship Award by the Govt of UK for Doctoral Studies, 1977.
• Distinguished Alumnus Award of the Dept. of Aerospace Eng. , IISc, Bangalore , 2003

Deputations Abroad

• Visited France(Dassault Aviation), UK (British Aerospace), Belgium (LMS) and USA (MOOG) for work connected with LCA Project
• Attended the 4th European Conference on Smart Materials and Structures at Harrogate , UK in 1999; also visited University of Sheffield
• Presented Invited Paper on behalf of Dr V K Aatre, SA to RM on ‘Status of R&D in Adaptive Structures in India ’ in the International Conference on Adaptive Structures at University of Maryland , USA in October 2001, also visited Ohio State University, Virginia Polytechnic Institute and State University
• Visited University of Trento in Italy as a member of the DST, Govt of India Delegation (2003)