Intelligent Structural Health Management

Intelligent Structural Health Management is an emerging concept that provides an efficient methodology to minimize the possibility of catastrophic failure of safety-critical structures. ISHM involves feedback-based prediction of structural integrity. On-board diagnostic sensors provide continuous or on-demand information about the state of a structure, and the data from the sensors is incorporated into structural analyses and damage evolution models to assess the state of the structure, and to make probabilistic prognoses about the remaining lifetime. The ISHM approach requires integration of several emerging and some mature sub-fields of science and engineering:

• Structural health monitoring
• Damage and failure mechanics
• Structural and reliability analysis
• Nondestructive materials characterization

Ongoing research activities include:

• Photoacoustic and acoustic characterization of composites, thin films and coatings
• Piezoelectric and fiber-optic sensors for structural health monitoring
• Ultrasonic nonlinearity for fatigue damage

Professor Krishnaswamy usually teaches these courses:

• Gen_Eng 205-2: Engineering Analysis 2: Mechanics (undergraduate)
• Gen_Eng 205-3: Engineering Analysis 3: Systems Dynamics (undergraduate)
• Mech_Eng 362: Stress Analysis (undergraduate and graduate)
• Mech_Eng 495: Photo-acoustic Methods of Materials Characterization (graduate level)
• Civ_Eng 219: Continuum Mechanics (undergraduate level)
• Civ_Eng 317: Mechanics of Continua (graduate level)

On his teaching philosophy, he says: "I see my role as a university teacher as that of a guide who helps technologically-inclined, motivated students navigate over territory that is unfamiliar to them. I expect the students to share my interests in science and technology. As a guide, my role is to show the students some of the technical landscape that they yearn to see, and perhaps more importantly, to inculcate in them the skills that will help them travel farther on their own. I endeavor to make my lectures interesting, clear, and to the point."

Sridhar Krishnaswamy, "Photoacoustic Methods of Materials Characterization," SEM Handbook on Experimental Mechanics, revised ed. W. Sharpe, Springer (in press).

Sridhar Krishnaswamy, "Theory and Applications of Laser Ultrasonic Techniques," in Ultrasonic Nondestructive Evaluation: Engineering and Biological Material Characterization, ed T. Kundu, CRC Press.

Feifei Zhang, Sridhar Krishnaswamy, Dong Fei, Douglas A. Rebinsky, Bao Feng, (2006)"Ultrasonic Characterization of Mechanical Properties of Diamond-Like Carbon Hard Coatings", Thin Solid Films, vol. 503, pp250-258.

Li Sun, Salil Kulkarni, Jan Achenbach, and Sridhar Krishnaswamy (2006) Couplant-effect independent technique for acoustic nonlinearity measurements", Journal of the Acoustical Society of America, vol. 20, No. 5, pp 2500-2505.

Yi Qiao, Yi Zhou, and Sridhar Krishnaswamy, (2006), "Adaptive two-wave mixing wavelength demodulation of Fiber Bragg Grating dynamic strain sensors", Applied Optics, vol. 45, No. 21, pp 5132-5142.

S. Kulkarni , L. Sun, B. Moran, Sridhar Krishnaswamy, and J.D. Achenbach, (2006), "A Probabilistic Method to Predict Fatigue Crack Initiation", International Journal of Fracture, vol. 137, pp9-17.

Younghoon Sohn and Sridhar Krishnaswamy, "Interaction of a Scanning Laser-generated Ultrasonic Line Source with a Surface-breaking Flaw," J. Acoust. Soc. Am. vol.115, No.1, 2004.

C.M. Hernandez, T.W. Murray, and Sridhar Krishnaswamy, "Photoacoustic Characterization of the Mechanical Properties of Thin Films," Applied Physics Letters , vol. 80, No. 4, 2002.

T.W. Murray, Sridhar Krishnaswamy, J.D. Achenbach, (1999), "Laser generation of ultrasound in films and coatings", Applied Physics Letters, vol. 74, No. 23, pp 3561-3563