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Ratneshwar (Ratan) Jha

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Ratneshwar (Ratan) Jha
Associate Professor
364 CAMP
Clarkson University
PO Box 5725
Potsdam, NY 13699-5725

Phone: 315-268-7686
Fax: 315-268-6695
E-mail: rjha@clarkson.edu
Curriculum Vitae

Educational Background
B.Tech., Aeronautical Engineering (Honors), Indian Institute of
Technology (1981)
M.S., Aerospace Engineering, Georgia Institute of Technology, (1982)
Ph.D., Mechanical Engineering, Arizona State University, (1999)

Teaching
Dr. Jha has graduated three Ph.D., nine M.S. students and two ME students and currently advises two PhD, and seven MS students.   He has also supervised three undergraduate Honors theses.

Courses taught include:
AE200- Aeronautical Engineering Seminar
AE350 - Aircraft Structural Analysis
AE429 - Aircraft Performance and Flight Mechanics
AE430 - Stability and Control of Aerospace Vehicles
AE458 - Design of Aircraft Structures
ME504 - Engineering Design Methodology

Research Interests
Prof. Jha has conducted research in structural health monitoring, modeling of composite and smart structures, adaptive control of structural vibrations, intelligent flight controls, and multidisciplinary design optimization. He has established the Smart Structures Laboratory at Clarkson University which is well equipped for vibration measurement and control experiments, including a scanning laser vibrometer. Dr. Jha's contributions include both theoretical and experimental research which have resulted in over 70 publications in international archival journals and refereed conferences. Dr. Jha is a member of the Editorial Board for International Journal of Aerospace Engineering.  Dr. Jha is an Associate Fellow of the American Institute of Aeronautics and Astronautics and a member of ASME and ASEE. He is a member of the AIAA Adaptive Structures Technical Committee and has served as Session Chair/Co-Chair for Adaptive Structures Conferences. He was awarded Graham Faculty Research Award by Clarkson University in 2005. Dr. Jha has received research grants from National Science Foundation, AFOSR, NASA, US Army, New York State Energy Research and Development Authority and several industries. Prior to joining Clarkson, Dr. Jha worked in the aerospace industry from 1983 to 1995 where he led a team of engineers working on conceptual and preliminary designs of combat aircraft. More information can be found on his research Web site.

Current Research Projects
Structural Health Monitoring (.pdf)
Our SHM research focuses on the development of damage detection algorithms through an understanding of structural mechanics, elastic wave propagation, and advanced signal processing. Interactions of Lamb waves with damages are studied to determine type and extent (severity) of damages. Both experimental work using PZT actuator/sensor as well as laser vibrometer and Spectral Finite Element models are employed for SHM. For vibration based damage detection of composite structures, we have developed algorithms using time series analysis and proper orthogonal decomposition. We have performed damage detection using modal methods and a novel signal processing technique known as Hilbert-Huang transform for bridge SHM project. Our research in probabilistic fatigue damage prognosis has resulted in an improved model updating procedure (compared to the classical Baysian updating) based on the maximum relative entropy approach. 

Adaptive Control of Smart Structures  (.pdf)
Smart structures represent a fundamental shift in design thinking by requiring structures to perform new functions in addition to the primary function of carrying load.  Envisioned added functions include vibration control, shape change on demand (morphing), health monitoring, and self-healing, leading to several high payoff applications.  The real-time sensing and actuation capabilities of smart structures provide powerful means for active vibration, shape, and position control of flexible structures.  Development of active control algorithms and experimental validation of their performance is a key requirement for practical applications of smart structures. Complex smart structures, employing a large number of distributed sensors and actuators, are likely to exhibit nonlinearity and variations with time.  We have developed the neural adaptive predictive controller by combining the adaptive neural network autoregressive external input model with the generalized predictive control technique. We have validated its performance experimentally and compared with other neurocontrollers and standard LQR. This controller is capable of coping with uncertainty, nonlinearity, and time variation, which are characteristics of complex structures.


Current Graduate Students
Xuefei Guan (PhD)
Sohaib Obeid (Ph.D.) 
Anshuman Kunwar (M.S.)
Omkar Dole (M.S.) 
Myles Farrell (M.S.) 
Inho Kim (M.S.) 
Dulip S. Widana-Gamage (M.S.) 
Peter Coffin (M.S.) 
Michael Vuto (M.S.) 

Selected Publications 

  1. C. Shane and R. Jha, "Proper Orthogonal Decomposition Based Algorithm for Detecting Damage Location and Severity in Composite Plates," Mechanical Systems and Signal Processing, in press (2010).
  2. B. LeFevre and R. Jha, "Attitude Dynamics of Square Solar Sails During Spin-Deployment," Proceedings of the Institution of Mechanical Engineers, Part G, Journal of Aerospace Engineering, in press (2010).
  3. X. Guan, R. Jha, Y. Liu, A. Saxena, J. Celaya and K. Goebel, "Comparison of Two Probabilistic Fatigue Damage Assessment Approaches Using Prognostic Performance Metrics," International Journal of Prognostics and Health Management, in press (2010).
  4. M.J. Whelan, M.V. Gangone, K.D. Janoyan and R. Jha, "Operational Modal Analysis of a Multi-Span Skew Bridge Using Real-Time Wireless Sensor Networks," Journal of Vibration and Control, in press (2010).
  5. S. Gopalakrishnan and R. Jha, "A Wavelet Spectral Element for Composite Plate with Delamination and Transverse Damage," AIAA 2010-2901, 18th AIAA/ASME/AHS Adaptive Structures Conference, Orlando, Florida (Apr 12-15, 2010).
  6. X. Guan, R. Jha and Y. Liu,"Probabilistic fatigue damage prognosis using maximum entropy approach," Journal of Intelligent Manufacturing,  Published online: 28 October 2009.
  7. M.J. Whelan, M.V. Gangone, K.D. Janoyan and R. Jha, "Real-Time Wireless Vibration Monitoring for Operational Modal Analysis of an Integral Abutment Highway Bridge," Engineering Structures, Volume 31, Issue 10,  pp. 2224-2235 (October 2009).
  8. P. Coffin, G. Ahmadi, R. Jha, P. Marzocca, W.-J. Su and L. Manole, " Design and Experimental Investigation of a Small UAV," 09ATC-0322, SAE AeroTech Congress and Exhibition, Seattle, Washington (November 10-12, 2009).
  9. B. LeFevre and R. Jha, "Hybrid Adaptive Launch Vehicle Ascent Flight Control," AIAA-2009-5958, AIAA Guidance, Navigation and Control Conference and Exhibit, Chicago, Illinois (Aug. 10-13, 2009).
  10. R. Jha and R.Watkins, "Lamb Wave Based Diagnostics of Composite Plates Using a Modified Time Reversal Method," AIAA-2009-2108, 17th AIAA/ASME/AHS Adaptive Structures Conference, Palm Springs, CA (May 4-7, 2009).
  11. A. Alavinasab, G. Ahmadi and R. Jha, "Nonlocal Continuum Theory Based Modeling of Carbon Nanotube Composites," SMASIS2008-595, ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Ellicott City, Maryland (October 28-30, 2008).
  12. A. Alavinasab, R. Jha, G. Ahmadi, C. Cetinkaya and I. Sokolov, "Computational Modeling of Nano-Structured Glass Fibers," Computational Materials Science, Vol. 44, pp. 622-627 (2008).
  13. R. Jha and C. He, "Adaptive Neurocontrollers for Vibration Suppression of Nonlinear and Time Varying Structures," Journal of Intelligent Material Systems and Structures, Vol. 15, No. 9-10, pp. 771-781 (Sept.- Oct. 2004).
  14. R. Jha and C. He, "A Comparative Study of Neural and Conventional Adaptive Predictive Controllers for Vibration Suppression," Smart Materials and Structures, Vol. 13, No. 4, pp. 811-818 (2004).
  15. R. Jha, M. Pausley and G. Ahmadi, "Optimal Active Control of Launch Vibrations of Space Structures," Journal of Spacecraft and Rockets, Vol. 40, No. 6, pp. 868-874 (November 2003).
  16. P.C. Chen, D. Sarhaddi, R. Jha, D.D. Liu,  K. Griffin and R. Yurkovich, "Variable Stiffness Spar Approach for Aircraft Maneuver Enhancement Using ASTROS," Journal of Aircraft, Vol. 37, No. 5, pp. 865-871 (Sept. - Oct. 2000).
  17. R. Jha and A. Chattopadhyay, "Multidisciplinary Optimization of Composite Wings Using Refined Structural and Aeroelastic Analysis Methodologies," Engineering Optimization, Vol. 32, pp. 59-78 (1999).
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