ELECTRO-MECHANICAL IMPEDANCE BASED SHM OF THICK STRUCTURES IN BROAD-BAND FREQUENCY SPECTRUM
Abstract
In this study, theoretical and experimental studies were conducted in terms of electro-mechanical impedance spectroscopy (EMIS) to monitor the structural health status of thick metallic bar structures in broad-band frequency in the range up to 15 MHz. Thus, in-plane (longitudinal-wise) and out-of-plane (thickness-wise) mode EMI spectra were included in this range of frequency. Then, the thickness mode EMIS peaks were focused for pristine thick steel bar as a baseline and for bars with simulated damage in different depths and different locations. For theoretical part of the study, coupled field finite element analyses (CF-FEA) were carried out by modeling piezoelectric wafer active sensor (PWAS) bonded on steel bars in pristine and in damaged status. The thickness mode EMIS results from both CF-FEA simulations and EMIS measurements were analyzed to investigate the effects of the damage location and size variations through a statistical pattern recognition method as damage index such as the root mean square deviation, RMSD, method. It was found that RMSD values were similar trend for experimental and CF-FEA.
Keywords
Structural Health Monitoring (SHM),,Electro-mechanical Impedance (EMI)
References
- [1] Aktan A, Helmicki A., Hunt V. Issues in health monitoring for intelligent infrastructure, Smart Mater Struct 1998; 7: 674-692. [2] Doebling SW, Farrar CR, Prime MB. A summary review of vibration-based damage identification methods, Shock and Vibration Digest 1998: 30, 91-105. [3] Shankar, R. An integrated approach for Structural health monitoring, PhD, Indian Institute of Technology, Delhi, India, 2009. [4] Rosiek M, Martowicz A, Uhl T, Stępiński T, Łukomski T. Electromechanical impedance method for damage detection in mechanical structures, 2010, Proceedings of 11th IMEKO TC, 10, 18-20. [5] Hamzeloo S R, Shamshirsaz M, Rezaei SM. Damage detection on hollow cylinders by electro-mechanical impedance method: Experiments and finite element modeling, CR Mecanique 2012: 340, 668-677. [6] Na S, Lee HK. Neural network approach for damaged area location prediction of a composite plate using electromechanical impedance technique, Compos Sci Technol 2013:88, 62-68. [7] Wang D, Song H, Zhu H. Numerical and experimental studies on damage detection of a concrete beam based on PZT admittances and correlation coefficient, Constr Build Mater 2013; 49, 564-574. [8] Ai D, Zhu H, Luo H, Yang J. An effective electromechanical impedance technique for steel structural health monitoring, Constr Build Mater 2014; 73, 97-104. [9] Hu X, Zhu H, Wang D. A study of concrete slab damage detection based on the electromechanical impedance method, Sensors 2014; 14, 19897-19909. [10] da Silveira R Z, Campeiro L M, Baptista F G. Analysis of Sensor Installation Methods in Impedance-based SHM Applications, Procedia Engineer 2016; 168, 1751-1754. [11] Tinoco H A, Robledo-Callejas L, Marulanda D J, Serpa AL. Damage detection in plates using the electromechanical impedance technique based on decoupled measurements of piezoelectric transducers, J Sound Vib 2016; 384, 146-162. [12] Liu, P, Wang W, Chen Y, Feng X, Miao L, Concrete damage diagnosis using electromechanical impedance technique, Constr Build Mater 2017; 136, 450-455. [13] Ai D, Zhu H, Luo H, Wang C. Mechanical impedance based embedded piezoelectric transducer for reinforced concrete structural impact damage detection: A comparative study, Constr Build Mater 2018; 165, 472-483. [14] Giurgiutiu V, Zagrai AN, Damage detection in thin plates and aerospace structures with the electro-mechanical impedance method, Struct Health Monit 2005; 4, 99-118. [15] Giurgiutiu V, Structural Health Monitoring with Piezoelectric Wafer Active Sensors, Academic Press Inc., 2014.