The Delay Multiply and Sum Algorithm for Lamb Waves Based Structural Health Monitoring

2021 ◽  
pp. 657-666
Author(s):  
Michelangelo Maria Malatesta ◽  
Denis Bogomolov ◽  
Marco Messina ◽  
Dennis D’Ippolito ◽  
Nicola Testoni ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Lamb Waves ◽  
Structural Health

Use of delay and sum for sparse reconstruction improvement for structural health monitoring

2019 ◽  
Vol 30 (18-19) ◽  
pp. 2919-2931 ◽  
Author(s):  
Ali Nokhbatolfoghahai ◽  
Hossein M Navazi ◽  
Roger M Groves
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Guided Waves ◽  
Lamb Waves ◽  
Spot Size ◽  
Sparse Reconstruction ◽  
Reconstruction Method ◽  
Structural Health ◽  
Computational Performance

To perform active structural health monitoring, guided Lamb waves for damage detection have recently gained extensive attention. Many algorithms are used for damage detection with guided waves and among them, the delay-and-sum method is the most commonly used algorithm because of its robustness and simplicity. However, delay-and-sum images tend to have poor accuracy with a large spot size and a high noise floor, especially in the presence of multiple damages. To overcome these problems, another method that is based on sparse reconstruction can be used. Although the images produced by the sparse reconstruction method are superior to the conventional delay-and-sum method, it has the challenges of the time and cost of computations in comparison with the delay-and-sum method. Also, in some cases in multi-damage detection, the sparse reconstruction method totally fails. In this article, using prior support information of the structure achieved by the delay-and-sum method, a hybrid method based on sparse reconstruction method is proposed to improve the computational performance and robustness of sparse reconstruction method in the case of multi-damage presence. The effectiveness of the proposed method in detecting damages is demonstrated experimentally and numerically on a simple aluminum plate. The technique is also shown to accurately identify and localize multi-site damages as well as single damage with low sampled signals.

Lamb Waves Signal Analysis in Structural Health Monitoring Systems

2011 ◽  
Vol 368-373 ◽  
pp. 2402-2405
Author(s):  
Nai Zhi Zhao ◽  
Chang Tie Huang ◽  
Xin Chen
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Structural Changes ◽  
Lamb Waves ◽  
Detection Algorithm ◽  
Operational Conditions ◽  
Structural Health ◽  
Detection Algorithms ◽  
Baseline Subtraction

Many of the wave propagation based structural health monitoring techniques rely on some knowledge of the structure in a healthy state in order to identify damage. Baseline measurements are recorded when a structure is pristine and are stored for comparison to future data. A concern with the use of baseline subtraction methods is the ability to discern structural changes from the effects of varying environmental and operational conditions when analyzing the vibration response of a system. The use of a standard baseline subtraction technique may falsely indicate damage when environmental or operational variations are present between baseline measurements and new measurements. A procedure was outlined for the method, including excitation and recording of Lamb waves, and the use of damage detection algorithms. In this paper, several tests are performed and the results are used to help develop the damage detection algorithms previously described, and to evaluate the performance of the instantaneous baseline SHM technique. Analytical testing is first performed by feeding known input signals into each damage detection algorithm and analyzing the output data. The results of the analytical testing are used to help develop the damage detection algorithms.

scholarly journals Wireless Energy Supply to Aircraft Structural Health Monitoring Nodes Using Ultrasonic Lamb Waves

2014 ◽  
Vol 2014 (6) ◽  
pp. 21-28 ◽  
Author(s):  
Aleksander Kural
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Lamb Waves ◽  
Sensor Nodes ◽  
Laser Vibrometer ◽  
Structural Health ◽  
Signal Laser ◽  
Plate Waves ◽  
Lamb Wave Propagation ◽  
Further Development

Abstract This article is based on research done during the author’s PhD at Cardiff University, UK. A prototype of a novel wireless energy transmission system aimed at the use with wireless aircraft structural health monitoring (SHM) sensor nodes is described. The system uses ultrasonic guided plate waves (Lamb waves) to transmit energy along an aluminium plate, similar to those used in aircraft structures. Three types of piezoelectric transducers generating and receiving the ultrasonic vibration were compared. The Smart Material MFC M8528-P1 was found to achieve the best performance, allowing the transmission of 17 mW across a 54 cm distance, while being driven with a 20 V signal. Laser vibrometer imaging and LISA software simulation of the Lamb wave propagation in the experimental plate were also performed. Based on these, ideas for a further development of the system were proposed.

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