Satish Nagarajaiah has lead the development of sparse structural system identification algorithms based on sparsity, time-frequency methods, wavelets, sparse regularization, statistical learning, filtering, low rank methods and physics guided machine learning. Satish Nagarajaiah group’s research thrust in structural system identification and damage detection has centered on the development of new low rank, sparse, compressive sensing, and time-frequency algorithms, based on machine and statistical learning, filtering, advanced signal processing techniques and computer vision techniques.  Recently his team of research collaborators were awarded the 2019 Takuji Kobori Prize, and 2017 Raymond C. Reese Research Prize for sparse structural identification.

Ph.D. students resulting from this research effort:

2021, Dr. Sutanu Bhowmick, “Vision-based Full-Field Sensing for Condition Assessment of Structural Systems,” Ph.D. Dissertation, CEVE, Rice University, M.S., IIT Kanpur, B.S. Jadavpur, India.

2021, Dr. Debashish Jana, “Vision and Learning based Sensing for Structural Health Monitoring” Ph.D. Dissertation, CEVE, Rice University, M.S. IIT Kanpur, IIEST. Shibpur, India.

2018, Dr. Debarshi Sen, “Applications of Statistical Learning and Stochastic Filtering for Damage Detection in Structural Systems,” Ph.D. Dissertation, CEVE, Rice University, B.S. and M.S., IIT Kharagpur. India.

2018, Dr. Zhilu Lai, “Sparse Structural System Identification and Damage Detection,” Ph.D. Dissertation, CEVE, Rice University, M.S. Hong-Kong-Polytech, B.S. Xiamen University, China.

2014, Dr. Yongchao Yang, “Harnessing data structure for health monitoring and assessment of civil structures: sparse representation and low-rank structure” Ph.D. Dissertation, CEVE, Rice University, B.S. Harbin Institute of Technology, China

2013, Dr. Chaojun Huang, “Structural Health Monitoring System for Deepwater Risers with Vortex-induced Vibration: Nonlinear Modeling, Blind Identification, Fatigue/Damage Estimation & Vibration Control” Ph. D. Dissertation, CEVE, Rice University, M.S. Tsinghua University, China, B.S. Tsinghua University, China

2012, Dr. Michael Contreras, “Neural Network based real time structural damage monitoring and fault detection and control” Ph. D. Dissertation, CEVE, Rice University (First Hispanic-American Student). M.S. UCLA, B.S. UCLA

2008, Dr. Chen Beili, “Detection Filter-based Method for Robust Structural Damage Detection,” Ph.D. Dissertation, CEVE, Rice University. M.S. Tsinghua University, China, B.S. Tsinghua University, China

2006, Dr. Li Zhiling, “Methods for real-time actuator-sensor failure and structural damage detection,” Ph.D. Dissertation, CEVE, Rice University. M.S. Tsinghua University, China, B.S. Tsinghua University, China

2006, Dr. Dharap Prasad, “Real-time structural damage monitoring using interaction matrix formulation and observers,” Ph.D. Dissertation, CEVE, Rice University. M.S. IIT-Bombay, India, B.S. VJIT, Bombay, India

2004, Dr. Sriram Narasimhan, “Control of smart base isolated buildings with new semiactive devices and novel H₂/LQG, H_∞, and time frequency controllers” Ph.D. Dissertation, CEVE, Rice University., M.S. Louisiana State University, B.S. Osmania University

2001, (defended in 2005), Dr. Nadathur Varadarajan, “Novel Smart Variable Stiffness Tuned Mass Damper and its Real Time Identification and Control using Time-frequency Techniques,” Ph.D. Dissertation, Rice University, Best graduate student award, CEVE. M.S. BITS-Pilani, India, B.S. BITS-Pilani, India

Papers resulting from our research is structural system identification and damage detection:

Key Overview Papers resulting from the overall research effort:

Bhowmick, S., & Nagarajaiah, S. (2021). Data-Driven Theory-guided Learning of Partial Differential Equations using SimultaNeous Basis Function Approximation and Parameter Estimation (SNAPE). (PDF), https://arxiv.org/abs/2109.07471

Sun, L., Shang, Z., Xia, Y., Bhowmick, S., and Nagarajaiah, S. (2020). “Review of Bridge Structural Health Monitoring Aided by Big Data and Artificial Intelligence: From Condition Assessment to Damage Detection,” Journal of Structural Engineering 146 (5), 04020073. DOI: https://doi.org/10.1061/(ASCE)ST.1943-541X.0002535  (PDF)

Lai, Z., Nagarajaiah, S. (2019) “Sparse structural system identification method for nonlinear dynamic systems with hysteresis/inelastic behavior,” Mechanical Systems and Signal Processing, 117, pp. 813-842. DOI:https://doi.org/10.1016/j.ymssp.2018.08.033  (PDF)

Nagarajaiah, S., and Yang, Y., (2017). “Modeling and harnessing sparse and low-rank data structure: a new paradigm for structural dynamics, identification, damage detection, and health monitoring”, Structural Control and Health Monitoring, 24(1), DOI: 10.1002/stc.1851. (Nagarajaiah_Yang-2017-Structural_Control_and_Health_Monitoring-2bxptrg)

Nagarajaiah, S., and Basu, B.  (2009) ” Output only Modal Identification and Structural Damage Detection using Time Frequency & Wavelet Techniques,” Earthquake Engineering and Engineering Vibration, DOI: 10.1007/s11803-009-9120-6, 8(4), 583-605 (Nagarajaiah_Basu_OutputOnly Modal ID using TFandWavelets_2009_EEEV-1qys2yc

Nagarajaiah, S. (2009) “Adaptive Passive, Semiactive, Smart Tuned Mass Dampers: Identification and Control using Empirical Mode Decomposition, Hilbert transform, and Short-Term Fourier transform,” Structural Control & Health Monitoring, DOI: 10.1002/stc.349, 16(7-8), 800-841 . (Nagarajaiah_APTMD_2009_SCHM-x6v3pn)

Select Other Papers resulting from the research effort:

Y Lei, D Xia, K Erazo, S Nagarajaiah, (2019) “A novel unscented Kalman filter for recursive state-input-system identification of nonlinear systems, “Mechanical Systems and Signal Processing 127, 120-135. DOI: https://doi.org/10.1016/j.ymssp.2019.03.013 (PDF)

Erazo, K., Sen, D., Nagarajaiah, S., Sun, L. (2019) “Vibration-based structural health monitoring under changing environmental conditions using Kalman filtering,” Mechanical Systems and Signal Processing, 117, pp. 1-15. DOI: https://doi.org/10.1016/j.ymssp.2018.07.041  (PDF)

Erazo, K. and Nagarajaiah, S., (2017). “An offline approach for output-only Bayesian identification of stochastic nonlinear systems using unscented Kalman filtering”, Journal of Sound and Vibration, 397, 222-240, DOI: 10.1016/j.jsv.2017.03.001.

Sen, D., Aghazadeh, A., Mousavi, A., Nagarajaiah, S., Baraniuk, R. (2019) ”Sparsity-based approaches for damage detection in plates,” Mechanical Systems and Signal Processing 117, pp. 333-346. DOI:https://doi.org/10.1016/j.ymssp.2018.08.019  (PDF)

Erazo, K., Nagarajaiah, S. (2018) ”Bayesian structural identification of a hysteretic negative stiffness earthquake protection system using unscented Kalman filtering,” Structural Control and Health Monitoring, 25(9), e2203. DOI: https://doi.org/10.1002/stc.2203  (PDF) – Winner of 2019 Takuji Kobori Prize

Sen, D., Erazo, K. and Nagarajaiah, S., (2017). “Bayesian estimation of acoustic emissions source in plate structures using particle-based stochastic filtering”, Structural Control and Health Monitoring, 24(11), DOI: 10.1002/stc.2005.

Yang, Y., Sun, P., Nagarajaiah, S., Bachilo, S.M. and Weisman, B.R., (2017). “Full-field, high-spatial-resolution detection of local structural damage from low-resolution random strain field measurements”, Journal of Sound and Vibration, 399, 75-85, DOI: 10.1016/j.jsv.2017.03.016.

Sen, D., Nagarajaiah, S. and Gopalakrishnan, S., (2017). “Harnessing sparsity in lamb wave-based damage detection for beams”, Structural Monitoring and Maintenance, 4(4), 381-396, DOI: 10.12989/smm.2017.4.4.381.

Yang, Y., Dorn, C., Mancini, T., Talken, Z., Nagarajaiah, S., Kenyon, G., Farrar, C., and Mascarenas, D., (2017). “Blind identification of full-field vibration modes of output-only structures from uniformly-sampled, possibly temporally-aliased (sub-Nyquist), video measurements”, Journal of Sound and Vibration, 390, 232-256, DOI: 10.1016/j.jsv.2016.11.034.

Yang, Y., and Nagarajaiah, S., (2017). “Robust data transmission and recovery of images by compressed sensing for structural health diagnosis”, Structural Control and Health Monitoring, 24(1), DOI: 10.1002/stc.1856.

Nagarajaiah, S., Chen, B. (2016). “Output only structural modal identification using matrix pencil method,” Structural Monitoring and Maintenance, techno press, 3 (4), 395-406.

Yang, Y., and Nagarajaiah, S., (2016). “Dynamic Imaging: Real-Time Detection of Local Structural Damage with Blind Separation of Low-Rank Background and Sparse Innovation”, Journal of Structural Engineering, 142(2), DOI: 10.1061/(asce)st.1943-541x.0001334.

Yang, Y., and Nagarajaiah, S., (2016). “Harnessing data structure for recovery of randomly missing structural vibration responses time history: Sparse representation versus low-rank structure”, Mechanical Systems and Signal Processing, 74, 165-182, DOI: 10.1016/j.ymssp.2015.11.009.

Chang, J., Liu, W.B., Hu, H., and Nagarajaiah, S., (2016). “Improved independent component analysis based modal identification of higher damping structures”, Measurement, 88, 402-416, DOI: 10.1016/j.measurement.2016.03.021.

Nagarajaiah, S. and Erazo, K. (2016). “Structural monitoring and identification of civil infrastructure in the United States”, Structural Monitoring and Maintenance, 3(1), 51-69, DOI: 10.12989/smm.2016.3.1.051.

Yang, Y., Li, S., Nagarajaiah, S., Li, H., and Zhou, P. (2016). “Real-Time Output-Only Identification of Time-Varying Cable Tension from Accelerations via Complexity Pursuit”, Journal of Structural Engineering, 142(1), DOI: 10.1061/(asce)st.1943-541x.0001337.

Nagarajaiah, S. and Yang, Y. (2015). “Blind modal identification of output-only non-proportionally-damped structures by time-frequency complex independent component analysis”, Smart Structures and Systems, 15(1), 81-97.

Yang, Y., Nagarajaiah, S., and Ni, Y.Q., (2015). “Data compression of very large scale structural seismic and typhoon responses by low-rank representation and with matrix reshape”, Structural Control and Health Monitoring, 22(8), 1191-1131, DOI: 10.1002/stc.1737.

Yang, Y. and Nagarajaiah, S. (2015). “Output-only modal identification by compressed sensing: Non-uniform low-rate sampling”, Mechanical Systems and Signal Processing, 56-57, 15-34, DOI: 10.1016/j.ymssp.2014.10.015.

Huang, C. and Nagarajaiah, S. “Output-Only Structural Health Monitoring for Deepwater Risers: Experimental Study of Wavelet Modified SOBI and Distributed Force Index Algorithm,“ International Journal of Structural Stability and Dynamics, DOI: 10.1142/S0219455414400100, 14(5), 1440010 (2014).

Yang, Y., Nagarajaiah, S. “Blind identification of damage in time-varying system using independent component analysis with wavelet transform,” Mechanical Systems and Signal Processing, DOI: 10.1016/j.ymssp.2012.08.029, 47(1-2), 3-20 (2014).

Huang, C. and Nagarajaiah, S. “Experimental study on bridge structural health monitoring using blind source separation method: arch bridge,” Structural Monitoring and Maintenance, DOI: 10.12989/smm.2014.1.1.069, 1(1), 69-87 (2014).

Yang, Y. and Nagarajaiah, S. “Data Compression of Structural Seismic Responses via Principled Independent Component Analysis.” Journal of Structural Engineering, 10.1061/(ASCE)ST.1943-541X.0000946 , 04014032, 140(7) (2014).

Yang, Y., Nagarajaiah, S. “Structural damage identification via blind feature extraction and sparse representation classification,” Mechanical Systems and Signal Processing, doi: 10.1016/j.ymssp.2013.09.009, 45(1): 1 – 23 (2014).

Arrigan, J., Huang, C., Staino, A., Basu, B., and Nagarajaiah, S. “A frequency tracking semi-active algorithm for control of edgewise vibrations in wind turbine blades,” Smart Structures and Systems, DOI: 10.12989/sss.2014.13.2.177, 13(2), 177-201 (2014).

Yang, Y., Nagarajaiah, S. “Blind denoising of structural vibration responses with outliers via principal component pursuit,” Structural Control and Health Monitoring, DOI: 10.1002/stc.1624, 21(6), 962-978. (2014).

Pasala, D. T. R., and Nagarajaiah, S. “Adaptive-length pendulum smart tuned mass damper using shape-memory-alloy wire for tuning period in real time,” Smart Structures and Systems, DOI: 10.12989/sss.2014.13.2.203, 13(2), 203-217 (2014).

Contreras, M.T., Pasala, D. T. R. and Nagarajaiah, S. “Adaptive length SMA pendulum smart tuned mass damper performance in the presence of real time primary system stiffness change,” Smart Structures and Systems, DOI: 10.12989/sss.2014.13.2.219, 13(2), 219-233 (2014).

Chen, B., and Nagarajaiah, S. “Flexibility-based structural damage identification using Gauss–Newton method,” Sadhana, DOI: 10.1007/s12046-013-0151-3, 38(4), 557-569 (2013).

Yang, Y., and Nagarajaiah, S. “Time-‐frequency Blind Source Separation Framework Using Independent Component Analysis for Output‐only Modal Identification of Highly-Damped‐damped Structures,” Journal of Structural Engineering, ASCE, DOI: 10.1061/(ASCE)ST.1943-541X.0000621, 139(10):1780–1793 (2013).

Yang, Y., Nagarajaiah, S. “Blind modal identification of output-only structures in time-domain based on complexity pursuit”, Earthquake Engineering and Structural Dynamics, DOI: 10.1002/eqe.2302, 42(13):1885–1905 (2013).

Yang, Y., Nagarajaiah, S. “Output-only modal identification with limited sensors using sparse component analysis,” Journal of Sound and Vibration, doi: 10.1016/j.jsv.2013.04.004, 332(19): 4741–4765 (2013).

Chen, B. and Nagarajaiah, S. “Observer-based structural damage detection using genetic algorithm,” Structural Control and Health Monitoring, DOI: 10.1002/stc.512, 20 (4): 520-531 (2013).

Contreras, M., Nagarajaiah, S. and Narasimhan, S. “Real time detection of stiffness change using a radial basis function augmented observer formulation,” Smart Materials and Structures, DOI: 10.1088/0964-1726/20/3/035013, 20 035013 (2011).

Basu, B. and Nagarajaiah, S. “A Multi-Scale Wavelet-LQR Controller for Linear Time Varying Systems” Journal of Engineering Mechanics, ASCE, DOI: 10.1061/(ASCE)EM.1943-7889.0000162, 136(9), 1143-1151 (2010).

Basu, B. and  Nagarajaiah, S. “A wavelet-based time-varying adaptive LQR algorithm for structural control ,” Engineering Structures,  DOI: 10.1016/j.engstruct.2008.01.011, 30 (9), 2470-2477 (2008).

Chen, B. and Nagarajaiah, S. “H_/H_inf structural damage detection filter design using iterative LMI approach” Smart Materials and Structures, DOI: 10.1088/0964-1726/17/3/035019, 17 (3) (2008).

Narasimhan, S. Suresh, S., Nagarajaiah, S. and Sundararajan, N. “On-Line Learning Failure-Tolerant Neural-Aided Controller for Earthquake Excited Structures” Journal of Engineering Mechanics, ASCE, DOI: 10.1061/(ASCE)0733-9399(2008), 134 (3), 258-268 (2008).

B. Basu, S. Nagarajaiah, A. Chakraborty “Online Identification of Linear Time-Varying Stiffness of Structural Systems by Wavelet Analysis,” International Journal of Structural Health Monitoring, DOI: 10.1177/1475921707081968, 7(1), 21-36 (2008).

Koh, B.H., Nagarajaiah, S., and Phan, M.Q. “Reconstructing structural changes in a dynamic system from experimentally identified state-space models,” Journal of Mechanical Science and Technology, DOI: 10.1007/s12206-007-1012-y, 22(01), 103-112 (2008).

Chen, B. and Nagarajaiah, S. “Structural damage detection using decentralized controller design method,” Smart Structures and Systems, 4(6), 779-794 (2008).

Li, Z., Koh, B. H., and Nagarajaiah, S. “Detecting sensor failure via decoupled error function and inverse input-output model,” Journal of Engineering Mechanics, ASCE,133 (11), 1222 – 1228, DOI: 10.1061/(ASCE)0733-9399(2007), 133:11(1222) (2007).

Chen, B., and Nagarajaiah, S. “Linear Matrix Inequality based robust fault detection and isolation using the eigenstructure assignment method,” Journal of Guidance, Control, and Dynamics, AIAA, DOI: 10.2514/1.27417, 30(6), 1831 – 1835 (2007)

Nagarajaiah, S., and Sonmez, E. “Structures of semiactive variable stiffness multiple tuned mass dampers under harmonic forces,” Journal of Structural Engineering, ASCE, 133(1), 67-77, DOI: 10.1061/(ASCE)0733-9445(2007), 133:1(67) (2007).

Dharap, P., Koh, B.H., and Nagarajaiah, S. “Structural health monitoring using ARMarkov observers,” Journal of Intelligent Material Systems and Structures, DOI: 10.1177/1045389×06058793, 17(6), 469-481 (2006).

Koh, B.H., Li, Z., Dharap, P., Nagarajaiah, S., and Phan, M.Q., “Actuator Failure Detection through Interaction Matrix Formulation,” Journal of Guidance, Control, and Dynamics, AIAA, DOI: 10.2514/1.11932, 28(5), 895-901 (2005).

Koh, B.H., Dharap, P., Nagarajaiah, S., and Phan, M.Q., “Real-time Structural Damage Monitoring by Input Error Function,” AIAA Journal, DOI: 10.2514/1.14008, 43(8), 1808-1814 (2005).

Narasimhan, S., and Nagarajaiah, S. “STFT Algorithm for Semiactive Control of Base Isolated Buildings with Variable Stiffness Isolation Systems Subjected to Near Fault Earthquakes,” Engineering Structures, DOI: 10.1016/j.engstruct.2004.11.010, 27, 514-523 (2005).

Nagarajaiah, S. and Varadarajan, N. “Semi-active control of wind excited building with variable stiffness TMD using short time Fourier transform,” Engineering Structures, DOI: 10.1016/j.engstruct.2004.10.015, 27(3), 431-441 (2005).

Nagarajaiah, S. and Li, Z. “Time segmented least squares identification of base isolated buildings,” Soil Dynamics and Earthquake Engineering Journal, DOI: 10.1016/j.soildyn.2004.04.004, 24(8), 577-586 (2004).

Varadarajan, N. and Nagarajaiah, S. “Wind response control of building with variable stiffness tuned mass damper using empirical mode decomposition and Hilbert Transform,” Journal of Engineering Mechanics, ASCE, DOI: 10.1061/(asce)0733-9399(2004)130:4(451), 130(4), 451-458 (2004).

Nagarajaiah, S. and Dharap, P. “Reduced order observer based identification of base isolated buildings,” Earthquake Engineering and Engineering Vibration, DOI: 10.1007/s11803-003-0007-7, 2(2), 237-244 (2003).