scholarly journals Developing Dynamic Digital Image Techniques with Continuous Parameters to Detect Structural Damage

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Structural Damage ◽  
High Speed ◽  
Low Cost ◽  
New Technology ◽  
Correlation Method ◽  
Image Correlation ◽  
Tsunami Disaster ◽  
Damage Degree

Several earthquakes with strong magnitude occurred globally at various locations, especially the unforgettable tsunami disaster caused by the earthquake in Indonesia and Japan. If the characteristics of structures can be well understood to implement new technology, the damages caused by most natural disasters can be significantly alleviated. In this research, dynamic digital image correlation method for using continuous parameter is applied for developing a low-cost digital image correlation coefficient method with advanced digital cameras and high-speed computers. The experimental study using cantilever test object with defect control confirms that the vibration mode calculated using this proposed method can highly express the defect locations. This proposed method combined with the sensitivity of Inter-Story Drift Mode Shape, IDMS, can also reveal the damage degree of damage structure. These test and analysis results indicate that this proposed method is high enough for applying to achieve the object of real-time online monitoring of structure.

High-speed digital-image correlation method

2009 ◽  
Vol 34 (13) ◽  
pp. 1955 ◽  
Author(s):  
Min Wang ◽  
Hao Wang ◽  
Yuwan Cen
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Correlation Method ◽  
Image Correlation ◽  
Digital Image Correlation Method

Digital Speckle Projection for Vibration Measurement by Applying Digital Image Correlation Method

2006 ◽  
Vol 326-328 ◽  
pp. 99-102 ◽  
Author(s):  
Fu Jun Yang ◽  
Xiao Yuan He
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Speckle Pattern ◽  
Plane Deformation ◽  
Correlation Method ◽  
Image Correlation ◽  
Vibration Measurement ◽  
Digital Image Correlation Method ◽  
Digital Speckle

Digital image correlation method (DICM) is described as a robust in-plane deformation measuring method due to its simple optical setup and the insensitivity against ambient noise. Based on DICM, digital speckle projection has been developed for shape measurement. This paper explores the possibilities for vibration analysis using digital speckle projection together with DICM. A digital speckle pattern, generated by computer, is projected on an object surface using an LCD projector. Then the dynamic deformation modulated speckle images are captured by a high-speed CCD camera and saved in the computer. By using the self-developed temporal sequence digital images correlation algorithm, the deformation and vibration mode can be analyzed quantitatively. The proposed method avoids using stroboscopic or laser illumination and simplifies the experimental setup for vibration measurement, while it is time-consuming thanks to calculating a large amount of correlation coefficients. The experimental performance on a harmonic-vibrating cantilever beam well demonstrates the validity of the new method.

scholarly journals Developing Dynamic Digital Image Correlation Technique to Monitor Structural Damage of Old Buildings under External Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Structural Damage ◽  
Damage Index ◽  
Correlation Method ◽  
Image Correlation ◽  
Correlation Technique ◽  
Frequency Change ◽  
External Excitation ◽  
Structural Reinforcement

The capacity of buildings to resist external excitation is an important factor to consider for the structural design of buildings. When subject to external excitation, a building may suffer a certain degree of damages, and its residual capacity to resist external excitation cannot be evaluated. In this research, dynamic digital image correlation method combined with parameter evaluation available in system identification is used to evaluate the structural capacity to resist external excitation. The results reveal possible building latent safety problems so that timely structural reinforcement or dismantling of the building can be initiated to alleviate further damages. The results of experiments using the proposed method conform to the results obtained using the conventional method, but this method is more convenient and rapid than the latter in the subsequent procedure of data processing. If only the frequency change is used, the damages suffered by the building can be detected, but the damage location is not revealed. The interstory drift mode shape (IDMS) based on the characteristic of story drift has higher sensitivity than the approximate story damage index (ADSI) method based on modal frequency and vibration type; however, both indices can be used to determine the degree and location of building damages.

A Low-Cost and Simplified Digital Image Correlation Software Package for Use in Undergraduate Teaching Laboratories

2016 ◽  
Author(s):  
Fritz Hieb ◽  
Michael Hargather
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Low Cost ◽  
Image Correlation ◽  
Undergraduate Teaching ◽  
Development Cycle ◽  
Undergraduate Laboratory ◽  
And Performance ◽  
As Stress

Digital image correlation (DIC) has become an industry staple quickly replacing classic techniques. High-speed images are taken of a material sample being deformed, then algorithms applied to calculate variables of sample deformation such as stress, strain, displacement and displacement velocity. Currently, the analysis technology is not available at the level of simplicity and accessibility needed to teach the methods in an undergraduate laboratory. This project aims to develop a single program to perform DIC that is simple to use, accurate, and available at low cost. This paper describes the state of current DIC algorithm research, drawbacks of available technologies, the development cycle of the software including the techniques used to obtain the necessary accuracy and performance, and a demonstration of the DIC functionality in comparison to results obtained from commercial software.

Development of Digital Image Correlation Technique to Monitor Structural Damage Based on Natural Frequency as Damage Index

2011 ◽  
Vol 71-78 ◽  
pp. 3899-3903
Author(s):  
Wen Pei Sung ◽  
Ming Hsiang Shih ◽  
Feng Jen Tsai
Keyword(s):  
Digital Image Correlation ◽  
Natural Frequency ◽  
Digital Image ◽  
Structural Damage ◽  
Damage Index ◽  
Correlation Method ◽  
Cost Effective ◽  
Image Correlation ◽  
Correlation Technique ◽  
Sufficient Information

Recently, some serious earthquakes happened in the world and seriously threaten the safety of the life and property of the people. Monitoring and measuring the quakeproof capacity of building need to install high cost sensitive instruments to provide sufficient information. A cost-effective and reliable method based on the applying digital image correlation method, DIC to monitor the natural frequency of building under excitation of earthquake as damage index is proposed in this research. Using DIC to monitor the structural damage based on the natural frequency as damage index can easily detect the structural damage after the excitation of earthquake. Test results reveal that sensitivity of this DIC method is superior to traditional data collected by installed accelerometers, ACC in structure.

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