Structural Damage Detection by Using Modal Data and Wave Propagation

Author(s):  
Toshiyuki Ikeshita ◽  
Toshihiro Nakane ◽  
Yoshikazu Kitagawa

Demand for monitoring systems applied to structures for quality assurance and for evaluating seismic risk is stronger than ever. Here, a monitoring systems to assess structural integrity was developed in which the damage-detection strategy uses two newly developed methods to first identify the damage sites globally (i.e., detect whether the damage occurred or not, and detect the story level) and to then evaluate the damage sites locally. One method identifies the sites and extent of damage globally by using an improved MDLAC (Multiple Damage Location Assurance Criterion) method by using modal data (i.e., frequency and mode shape), and the other identifies the damage sites locally by using wave propagation. Results showed that these two methods are practical and effective in assessing structural integrity of a structure for seismic safety.

2011 ◽  
Vol 368-373 ◽  
pp. 1667-1671
Author(s):  
Yu Zhang ◽  
Long Yu ◽  
Yun Ju Yan ◽  
Yu Guo

Over decades phased array antenna technique attracts much more attention in Lamb wave based structural damage detection. Lamb wave generated by the piezoelectric wafers omnidirectionally could be steered at a specific direction during its propagation. Thus, the wave beam steering and focusing has been established, the location of structural damage is done with pulse-echo method by wave propagation. However, the detection accuracy will decrease as side bands energy leakage during wave propagation, so, signals to be generated have to be modified by window tone burst in order to concentrate energy in main bands and minimize the effect of dispersion side bands. In this paper, signals modified by Hanning-windowed tone burst was used to decrease the effect of side bands energy leakage, the results improved the detection accuracy better than signals without window tone burst and show good agreement with theoretical results. Meanwhile, A numerical simulation of aluminium plate demonstrates that phased array antenna technique is feasible in structural damage detection.


2009 ◽  
Vol 413-414 ◽  
pp. 125-132 ◽  
Author(s):  
Ser Tong Quek ◽  
Viet Anh Tran ◽  
Xiao Yan Hou

For detection of damage in frame and truss structures, the normalized cumulative energy is proposed as the identification parameter within the framework of the damage locating vector (DLV) method. Due to the limited number of sensors used, it is necessary to filter out the actual damaged elements from the identified set of potential damaged elements. An intersection scheme using only the measured signals is proposed for the filtering and verified using a warehouse frame comprising truss, beam and column elements. As wireless sensors are introduced into structural health monitoring systems, loss of data during transmission is one significant issue which needs to be addressed. An algorithm to patch the loss data is proposed and when integrated with the proposed damage detection method is experimentally shown to be feasible using a cantilever truss.


2013 ◽  
Vol 438-439 ◽  
pp. 535-538
Author(s):  
Lei Zhao ◽  
Yu Zhao

Over decades phased array antenna technique attracts much more attention in Lamb wave based structural damage detection. Lamb wave generated by the piezoelectric wafers omnidirectionally could be steered at a specific direction during its propagation. Thus, the wave beam steering and focusing has been established, the location of structural damage is done with pulse-echo method by wave propagation. However, the detection accuracy will decrease as side bands energy leakage during wave propagation, so, signals to be generated have to be modified by window tone burst in order to concentrate energy in main bands and minimize the effect of dispersion side bands. In this paper, signals modified by Hanning-windowed tone burst was used to decrease the effect of side bands energy leakage, the results improved the detection accuracy better than signals without window tone burst and show good agreement with theoretical results. Meanwhile, a numerical simulation of aluminium plate demonstrates that phased array antenna technique is feasible in structural damage detection.


2013 ◽  
Vol 17 (1) ◽  
pp. 216-223 ◽  
Author(s):  
Seyed Sina Kourehli ◽  
Abdollah Bagheri ◽  
Gholamreza Ghodrati Amiri ◽  
Mohsen Ghafory-Ashtiany

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