Research on the Multi-Actuator and Sensor Detecting Technology Based on Piezoelectric Composite Materials

2015 ◽  
Vol 1120-1121 ◽  
pp. 1363-1367
Author(s):  
Zi Ping Wang ◽  
Xing Jia Li
Keyword(s):  
Structural Engineering ◽  
Crack Detection ◽  
Damage Identification ◽  
Piezoelectric Composite ◽  
Hilbert Huang Transform ◽  
Ultrasonic Methods ◽  
Strain Waves ◽  
Highly Sensitive ◽  
Non Destructive ◽  
Plane Specimen

Traditional ultrasonic methods are popular in identifying easily detectable cracks, but are not good enough in minute crack detection. Early damage identification is important in preventing larger crack development and future catastrophes. Highly sensitive and precise actuator/sensor is employed to improve the detection capability of these minute cracks. The Orthotropic Piezoelectric Composite Material (OPCM) has been developed as a functional material that can be conveniently used as a highly sensitive actuator/sensor. Comparing the OPCM with the traditional elements, the former has the ability of exciting and receiving focus power and directional strain waves. They have been used in non-destructive technology in many structural engineering inspections. Using the filtering capabilities of the OPCM sensor and Hilbert-Huang Transform (HHT) method, the experimental results show that by using the multi-actuator and sensor, the simulated cracks inside aluminum plane specimen can be successfully identified.

scholarly journals Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez
Keyword(s):  
Optical Transmission ◽  
Terahertz Spectroscopy ◽  
Design Guidelines ◽  
Two Dimensional ◽  
Highly Sensitive ◽  
Transmission Measurements ◽  
Metal Gratings ◽  
Low Sensitivity ◽  
Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

Vibration-Based Crack Detection in L-Frames

2014 ◽  
Vol 658 ◽  
pp. 261-268
Author(s):  
Jean Louis Ntakpe ◽  
Gilbert Rainer Gillich ◽  
Florian Muntean ◽  
Zeno Iosif Praisach ◽  
Peter Lorenz
Keyword(s):  
Strain Energy ◽  
Crack Detection ◽  
Natural Frequencies ◽  
Vibration Modes ◽  
Structural Elements ◽  
Element Analysis ◽  
Accurate Localization ◽  
Mathematical Expressions ◽  
Measurement Results ◽  
Non Destructive

This paper presents a novel non-destructive method to locate and size damages in frame structures, performed by examining and interpreting changes in measured vibration response. The method bases on a relation, prior contrived by the authors, between the strain energy distribution in the structure for the transversal vibration modes and the modal changes (in terms of natural frequencies) due to damage. Using this relation a damage location indicator DLI was derived, which permits to locate cracks in spatial structures. In this paper an L-frame is considered for proving the applicability of this method. First the mathematical expressions for the modes shapes and their derivatives were determined and simulation result compared with that obtained by finite element analysis. Afterwards patterns characterizing damage locations were derived and compared with measurement results on the real structure; the DLI permitted accurate localization of any crack placed in the two structural elements.

scholarly journals Pattern Deep Region Learning for Crack Detection in Thermography Diagnosis System

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 612 ◽  
Author(s):  
Jue Hu ◽  
Weiping Xu ◽  
Bin Gao ◽  
Gui Tian ◽  
Yizhe Wang ◽  
...  
Keyword(s):  
Crack Detection ◽  
Pattern Mining ◽  
Learning Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulsed Thermography ◽  
Testing Technology ◽  
Deep Region ◽  
Detection And Localization ◽  
Non Destructive

Eddy Current Pulsed Thermography is a crucial non-destructive testing technology which has a rapidly increasing range of applications for crack detection on metals. Although the unsupervised learning method has been widely adopted in thermal sequences processing, the research on supervised learning in crack detection remains unexplored. In this paper, we propose an end-to-end pattern, deep region learning structure to achieve precise crack detection and localization. The proposed structure integrates both time and spatial pattern mining for crack information with a deep region convolution neural network. Experiments on both artificial and natural cracks have shown attractive performance and verified the efficacy of the proposed structure.

Microtapered long period gratings: Non-destructive fabrication, highly sensitive torsion sensing, and tunable broadband filtering

2019 ◽  
Vol 102 ◽  
pp. 103000 ◽  
Author(s):  
Jihong Liu ◽  
Minhui Cheng ◽  
Xudong Kong ◽  
Dongdong Han ◽  
Jun Dong ◽  
...  
Keyword(s):  
Long Period ◽  
Long Period Gratings ◽  
Highly Sensitive ◽  
Non Destructive

scholarly journals Development of a Structural Integrity Non-destructive Inspection System for Bridges Made of Weathering Steel

2019 ◽  
Vol 278 ◽  
pp. 03006
Author(s):  
Björn Torsten Salmen ◽  
Marina Knyazeva ◽  
Frank Walther
Keyword(s):  
Structural Steel ◽  
Crack Detection ◽  
Structural Integrity ◽  
Test Methods ◽  
Point Of View ◽  
Inspection System ◽  
Weathering Steel ◽  
Steel Bridge ◽  
Electro Magnetic ◽  
Non Destructive

Due to the increasing volume of traffic, bridges are exposed to higher loads as it was considered during the planning phase. Therefore, a regular inspection is necessary in order to detect cracks at very early stages. The use of weathering structural steel in bridges, as well as in composite bridge constructions is an alternative to conventional bridges, not only from an economic but also from an ecological point of view, since it is not necessary to apply a corrosion protection layer and renew it during the lifetime of the bridge. Unfortunately, conventional visual inspection or magnetic particle inspection on the weathering steel bridge are hindered by the protective patina and requires development of new test methods. Within the framework of this project, a combined crack detection technique using non-destructive inspection by means of Active Thermography and by Electro-Magnetic Acoustic Transducer (EMAT) were evaluated in laboratory environments and in real conditions on bridge structures made of weathering structural steel.

Sign in / Sign up

Export Citation Format

Share Document