Bond characteristics of CFRP-to-steel joints. (November 2017)

• Record Type: Journal Article
• Authors: Yang, Yongming; Biscaia, Hugo; Chastre, Carlos; Silva, Manuel A.G.
• Is Part Of: Journal of constructional steel research. Volume 138(2017)
• Page Start: 401
• Page End: 419
• Publication Date: 2017-11
• Subjects: Bond -- CFRP-to-steel joint -- Bond-slip curve -- Pull-pull tests -- Closed-form solutions; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2017.08.001
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: Carbon Fiber Reinforced Polymer (CFRP) composites have a large potential for strengthening and retrofitting steel parts but due to their premature debonding from steel, further data and research are still required for wider application in such situations. In the present paper, the bond characteristics of CFRP-to-steel joints in pull-pull loaded conditions were studied. Monotonic loading of the double strap joints with different bond lengths was applied and the failure modes and interfacial bond-slip curves were obtained. A tri-linear bond-slip model is proposed and it was derived from the experimental data. A closed-form solution approach is also proposed based on the tri-linear bond-slip model. The strength of the CFRP-to-steel interface, the distribution of the relative displacements between bonded materials, the strains developed in the CFRP laminate and the bond stresses along the interface are reported and the closed-form solution is compared with the experimental results. Two cases are selected for presentation: (i) one with the bond length greater than the effective bond length; and, inversely, (ii) one with bond length which is shorter than the effective bond length. The results predicted by the closed-form solutions are shown to be accurate enough when compared to the experiments. Graphical abstract: Highlights: The debonding failure process of double strap CFRP-to-steel joints are presented and discussed; The experimental outcomes from 35 samples with different bond lengths revealed an adhesive failure mode; A closed-form solution based on a tri-linear bond-slip model is proposed; The experimental and analytical load-slip responses of the samples are reported; The effective bond length of the CFRP-to-steel interface is determined.