Structural health monitoring

About: Structural health monitoring is a research topic. Over the lifetime, 11727 publications have been published within this topic receiving 186231 citations.

Enhanced flexural wave sensing by adaptive gradient-index metamaterials.

Abstract: Increasing sensitivity and signal to noise ratios of conventional wave sensors is an interesting topic in structural health monitoring, medical imaging, aerospace and nuclear instrumentation. Here, we report the concept of a gradient piezoelectric self-sensing system by integrating shunting circuitry into conventional sensors. By tuning circuit elements properly, both the quality and quantity of the flexural wave measurement data can be significantly increased for new adaptive sensing applications. Through analytical, numerical and experimental studies, we demonstrate that a metamaterial-based sensing system (MBSS) with gradient bending stiffness can be designed by connecting gradient negative capacitance circuits to an array of piezoelectric patches (sensors). Furthermore, we demonstrate that the proposed system can achieve more than two orders of magnitude amplification of flexural wave signals to overcome the detection limit. This research encompasses fundamental advancements in the MBSS with improved performance and functionalities, and will yield significant advances for a range of applications.

Dual use of PZT patches as sensors in global dynamic and local electromechanical impedance techniques for structural health monitoring

Abstract: In this article, a new approach is proposed to effectively detect the initiation and progression of structural damage by combining the global dynamic and the local electromechanical impedance (EMI) techniques, using the same set of surface-bonded piezoelectric ceramic (PZT) patches as sensors. The PZT patches are used to determine the natural frequencies and the strain mode shapes of the structure (for use in the global dynamic technique) as well as to acquire the electromechanical admittance signature (for use in the EMI technique) to facilitate an improved damage assessment. Occurrence and location of the incipient damage are determined using the EMI technique, whereas for moderate to severe damages, the location and the severity are arrived at through the global dynamic technique. Finally, damage severity is determined in terms of the original stiffness of structure using the strain mode shapes directly determined using the PZT patches. The proposed technique is illustrated using two specimens—a 4-m lo...

Structural Health Monitoring with Piezoelectric Wafer Active Sensors for Space Applications

Abstract: Ultrasonic guided waves inspection using Lamb waves is suitable for damage detection in metallic structures. This paper will present experimental results obtained using guided Lamb waves to detect flaws in aluminum specimens with design features applicable to space applications. Two aluminum panels were fabricated from a variable-thickness aluminum top plate, with two bolted I-beams edge stiffeners and four bonded angle stiffeners. Artificial damages were introduced in the two panels: cracks, corrosions, and disbonds. The proposed investigation methods used bonded piezoelectric wafer active sensors to excite and receive Lamb waves. Three wave propagation methods were used: pitch-catch, pulse-echo, and the embedded ultrasonic structural radar. In addition, we also used a standing-wave damage detection technique, the electromechanical impedance method. The paper will present in detail the salient results from using these methods for damage detection and structural health monitoring. Where appropriate, comparison between different methods in detecting the same damage will be performed. The results have demonstrated the ability of piezoelectric wafer active sensors working in conjunction with guided Lamb waves to detect various types of damages present in complex geometry structures typical of space applications.