Collaborators:

• • Prof. Staszewski, AGH University of Science and Technology, Poland 

Funding:

• • Air Force Office of Scientific Research

  • Los Alamos/UCSD Educational Collaboration Program

  • Los Alamos/UCSD Cooperative Agreement in Research and Education (CARE)

Synopsis:

It is known that Structural Health Monitoring systems for continuous monitoring have to deal with the detrimental effects of changing temperature. This is true for a bridge (temperature changes at different times of the day) or for an aircraft (temperature changes from storage in closed hangers – typ. 60ºC – to high altitude flights – typ. -40ºC). This study involves theoretical analyses and experimental testing to identify the role of temperature on pitch-catch guided wave SHM systems. We studied both monolithic PZT transducer disks and flexible Macro-Fiber Composite (MFC) transducer patches. For both of these cases, we have developed theoretical models that include shear-lag behavior at the transducer-structure interface. We have also studied both aluminum panels and CFRP composite panels as test structures, with a temperature range of -40ºC to 60ºC typical of aircraft operations. We have found that the properties of the transducer itself (piezoelectric and dielectric permittivity constants) play a key role on the sensitivity of the guided wave system to temperature changes. We have also developed “temperature sensitivity” curves for various cases of piezoelectric transducers and test structures. These curves can enable compensating for temperature effects in guided-wave SHM systems, thereby ensuring accurate condition assessment of the structure under changing environmental conditions.

Selected Publications:

Kijanka, P, Packo, P., Zhu, X., Staszewski, WJ., and Lanza di Scalea, F., “Actuation Stress Modelling of Piezoceramic Transducers Under Variable Temperature Field,” Journal of Intelligent Materials Systems and Structures, 27(3), pp. 337-349, 2016 .

Kijanka, P, Packo, P., Zhu, X., Staszewski, WJ., and Lanza di Scalea, F., “Three-Dimensional Temperature Effect Modelling of Piezoceramic Transducers Used for Lamb Wave Based Damage Detection,” Smart Materials and Structures, 24(6), pp. 1-10, 2015 .

Salamone, S., Bartoli, I., Lanza di Scalea, F., and Coccia, S., “Guided-wave Health Monitoring of Aircraft Composite Panels under Changing Temperature,” Journal of Intelligent Materials Systems and Structures, Vol. 20(9), pp. 1079-1090, 2009.

Salamone, S., Fasel, T., Bartoli, I., Srivastava, A., Lanza di Scalea, F., and Todd, M., “Structural Health Monitoring of Adhesively-Bonded Joints in Aerospace Structures,” Materials Evaluation, Special Issue on Bond Inspection, Vol. 67(7), pp. 828-836, 2009. 

Lanza di Scalea, F. and Salamone, S., “Temperature Effects in Ultrasonic Lamb Wave Structural Health Monitoring Systems,” Journal of the Acoustical Society of America, Vol. 124(1), pp. 161-174, 2008.

Salamone, S., Bartoli, I., Lanza di Scalea, F., Coccia, S., “Temperature Effects on Guided Wave Based Macrofiber Composite Transduction,” Materials Evaluation, Vol. 66(10), pp. 1071-1076, 2008.