Browse > Article
http://dx.doi.org/10.4334/JKCI.2017.29.1.033

Evaluation on Strain and Necking Region of the Rebar by Using Image Processing Method  

Cheung, Jin-Hwan (Dept. of Civil Engineering, Pusan National University)
Lee, Jong-Han (Dept. of Civil Engineering, Daegu University)
Woo, Tae-Ryeon (Dept. of Civil Engineering, Pusan National University)
Jung, Chi-Young (Seismic Simulation Test Center, Pusan National University)
Publication Information
Journal of the Korea Concrete Institute / v.29, no.1, 2017 , pp. 33-42 More about this Journal
Abstract
This study conducted uniaxial tension tests on D10, D19, D29, and D35 SD400 steel-grade rebar and evaluated the strain distributions and necking regions to provide basic data for resolving differences between evaluation methods. Owing to the limitations of the existing measurement methods, this study conducted detailed evaluations of the strain of the rebar and necking regions using image processing, which is almost limitless on the measurement range and can easily distinguish measurement regions. The strain was concentrated at the region where necking occurred when the rebar approached its ultimate strength, which was successfully confirmed through image processing. The correlation between the length of the necking region and the diameter of the rebar could be analyzed by evaluating the necking region that occurs during the ultimate behavior of the rebar. According to the results, the length of the necking region is around 1.5~2.5 times the diameter of the rebar.
Keywords
strain; rebar; strain distribution; necking; image processing method;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
연도 인용수 순위
1 ASTM A 370-14, Standard Test Methods and Definitions for Mechanical Testing of Steel Products, ASTM International 2014.
2 KS B 0802:2013, Method of Tensile Test for Metallic Materials, Korean Agency for Technology and Standards 2013.
3 JIS Z 2241:2011, Metallic Materials - Tensile Testing - Method of Test at Room Temperature, Japaness Industrial Standard 2011.
4 Wahbeh, A., Caffrey, J. P., and Masri, S. F., "A Vision-based Approach for the Direct Measurement of Displacements in Vibrating Systems", Smart Materials and Structures, Vol. 12, No. 5, 2003, pp. 785-794.   DOI
5 Lee, J. J., and Shinozuka, M., "Real-time Displacement Measurement of a Flexible Bridge Using Digital Image Processing techniques", Experimental Mechanics, Vol. 46, No. 1, 2006, pp. 105-114.   DOI
6 Ji, Y. F., Chang, C. C., "Nontarget Image-based Technique for Small Cable Vibration Measurement", Journal of Bridge Engineering, Vol. 13, No. 1, 2008, pp. 34-42.   DOI
7 Kwon, Y. G., Han, S. H., and Hong, K. N., "Estimation of Local Strain Distribution of Shear-Compressive Failure Type Beam Using Digital Image Processing Technology", Journal of the Korea Concrete Institute, Vol. 21, No. 2, 2009, pp. 121-127.   DOI
8 Barranger, Y., Doumalin, P., Dupre, J. C., and Germaneau, A., "Strain Measurement by Digital Image Correlation: Influence of Two Types of Speckle Patterns Made from Rigid or Deformable marks", Strain, Vol. 48, 2012, pp. 357-365.   DOI
9 Kim, S. D., Jung, C. Y., Woo, T. R., and Cheung, J. H., "Application of Image Processing Method to Evaluate Ultimate Strain of Rebar", Journal of the Korea Institute for Structural Maintenance and Inspection, Vol. 20, No. 3, 2016, pp. 111-121.   DOI
10 KS D 3504:2016, Steel Bars for Concrete Reinforcement, Korean Agency for Technology and Standards 2016.
11 ISO 2394:2015, General Principles on Reliability for Structures, International Standard Organization 2015.
12 Park, S. J., Kang, T. S., and Moon, D. Y., "A Study on the Flexural Minimum Reinforcement for Prevention of Brittle Failure Specified in KCI and EN Codes", Journal of the Korea Concrete Institute, Vol. 26, No. 2, 2014, pp. 211-218.   DOI
13 Lee, J. H., Kim, D. H., and Choi, J. H., "Evaluation of Minimum Extensibility Standard Requirements for Steel Reinforcement", Journal of the Korea Concrete Institute, Vol. 23, No. 5, 2011, pp. 559-567.   DOI
14 ISO 15630-1:2010, Steel for the Reinforcement and Prestressing of Concrete - Test Methods - Part 1: Reinforcing Bars, Wire Rod and Wire, International Standard Organization, 2014.