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http://dx.doi.org/10.11112/jksmi.2020.24.6.25

Study on Tensile Properties of Carbon Fiber Reinforced Polymers (CFRP) Laminate with Strain Distribution  

Kim, Yun-Gon (Daegu University)
Publication Information
Journal of the Korea institute for structural maintenance and inspection / v.24, no.6, 2020 , pp. 25-33 More about this Journal
Abstract
To investigate the relationship between strain distribution and tensile properties of brittle material, five types of tensile coupon of carbon fiber reinforced polymer (CFRP) modified the tab portion in order to have a strain distribution including S0, SD1, SD2, SV1, SV2 were tested. The ultimate stress and strain of SD2 and SV2 which was intended to have larger strain distribution were smaller than those of SD1 and SV1, that was more clearly shown in the test results of the symmetric coupons (SV series) than the asymmetric coupons (SD series). In addition, the ultimate stress and strain of most coupons with strain distribution in this study were decreased when compared to the control group with uniform strain. These results were analyzed in various ways through 1) the average of the strain values directly measured by the strain gages, 2) the converted strain calculated by dividing the total deformation by the effective length, and 3) the ultimate effective strain derived from both the elastic modulus and the ultimate load. The values measured by strain gage indicates response of the local region precisely, but it does not represent the response from whole section. However, the converted strain and effective strain can supplement disadvantage of gage because they represent the average response of whole section. In particular, the effective strain can provide rupture strain conservatively, which can be utilized in practice, when the value obtained by strain gage was not effective due to gage damage or abnormal gage readings near ultimate load. This value provides a value that can be used even when partial rupture has occurred and is reasonably useful for specimens with strain distribution.
Keywords
carbon fiber reinforced polymers; coupon test; strain distribution; converted strain; effective strain;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
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1 ACI Committee 440 (2017), Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-17), American Concrete Institute, 110.
2 ASTM D3039 (2007), "Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials", American Society for Testing Materials (ASTM International), 13.
3 ASTM D7290-06 (2011), Standard Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications, American Society for Testing Materials, 4.
4 Bank, L. (2006), Composites for Construction: Structural Design with FRP Materials, Wiley, 560.
5 Kim, Y. (2011), Shear Behavior of Reinforced Concrete T-Beams Strengthened with Carbon Fiber Reinforced Polymer Sheets and CFRP anchors, Ph.D Dissertation. The University of Texas at Austin, 23(3), 17-24.
6 Kim, Y. (2019a), "Evaluation and Modification of Tensile Properties of Carbon Fiber Reinforced Polymer(CFRP) as Brittle Material with Probability Distribution", J Korea Inst. Struct. Maint. Insp., 23(3), 17-24.
7 Kim, Y. (2019b), Study on Strain Response Converted from Deformation in Tensile Test of Carbon Fiber Reinforced Polymers (CFRP), J Korea Inst. Struct. Maint. Insp., 23(4), 137-144.
8 NCHRP Report 655 (2010), Recommended Guide Specification for the Design of Externally Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements, Transportation Research Board, 118.
9 Weibull, W. (1951), A statistical distribution function of wide applicability, Journal of Applied Mechanics,. ASME, 18, 293-297.   DOI