Experimental Study of Effect of Temperature Variations on the Impedance Signature of PZT Sensors for Fatigue Crack Detection Saqlain Abbas 1,2,* , Fucai Li 1 , Zulkarnain Abbas 3,4 , Taufeeq Ur Rehman Abbasi 5 , Xiaotong Tu 6 and Riffat Asim Pasha 7 1 Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiaotong University, Shanghai, 200240, China 2 Department of Mechanical Engineering, University of Management and Technology, Sialkot Campus, Sialkot, Pakistan 3 Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai, 200240, China 4 Department of Mechanical Engineering, National Fertilizer Cooperation (NFC), Institute of Engineering and Technology, Multan, Pakistan 5 Department of Mechanical Engineering, Mirpur University of Science and Technology (MUST), Mirpur, 10250, Pakistan 6 The School of Information Science and Engineering, Xiamen University, Xiamen, 361005, China 7 Mechanical Engineering Department, UET Taxila, Taxila, Pakistan * Corresponding Author: Saqlain Abbas. Email: saq-abbas@sjtu.edu.cn Received: 19 August 2020 Accepted: 10 December 2020 ABSTRACT Structural health monitoring (SHM) is recognized as an efficient tool to interpret the reliability of a wide variety of infrastructures. To identify the structural abnormality by utilizing the electromechanical coupling property of piezo- electric transducers, the electromechanical impedance (EMI) approach is preferred. However, in real-time SHM applications, the monitored structure is exposed to several varying environmental and operating conditions (EOCs). The previous study has recognized the temperature variations as one of the serious EOCs that affect the optimal performance of the damage inspection process. In this framework, an experimental setup is developed in current research to identify the presence of fatigue crack in stainless steel (304) beam using EMI approach and estimate the effect of temperature variations on the electrical impedance of the piezoelectric sensors. A regular series of experiments are executed in a controlled temperature environment (25°C–160°C) using 202 V1 Constant Tempera- ture Drying Oven Chamber (Q/TBXR20-2005). It has been observed that the dielectric constant ð" 33 T Þ which is recognized as the temperature-dependent constant of PZT sensor has sufficiently influenced the electrical impe- dance signature. Moreover, the effective frequency shift (EFS) approach is optimized in term of significant tempera- ture compensation for the current impedance signature of PZT sensor relative to the reference signature at the extended frequency bandwidth of the developed measurement system with better outcomes as compared to the pre- vious literature work. Hence, the current study also deals efficiently with the critical issue of the width of the fre- quency band for temperature compensation based on the frequency shift in SHM. The results of the experimental study demonstrate that the proposed methodology is qualified for the damage inspection in real-time monitoring applications under the temperature variations. It is capable to exclude one of the major reasons of false fault diag- nosis by compensating the consequence of elevated temperature at extended frequency bandwidth in SHM. KEYWORDS Electromechanical impedance; structural health monitoring; piezoelectric sensors; fatigue crack; temperature compensation This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. DOI: 10.32604/sv.2021.013754 ARTICLE ech T Press Science