Browsing by Author "Perera, UND"

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item: Article-Full-text
An analytical approach to predict cohesion and interfacial failures of CFRP/steel composites under prolonged exposure to aqueous solutions
(Elsevier, 2022) Perera, UND; Arachchi, KADYT. K; Gamage, JCPH
The long-term performance of Carbon Fibre Reinforced Polymer (CFRP) strengthened steel joint under prolonged exposure to moisture conditions is imperative in the applications of structures exposed to groundwater or seawater. Analytical models to determine the bond characteristics of CFRP/steel composites subjected to prolonged exposure in aqueous solutions are yet to be explored. This paper explores the cohesive and interfacial failure parameters of such CFRP/Steel composites theoretically. Thirty double-strap joints and twenty adhesive coupons were tested to determine the residual strength after exposure to seawater and distilled water for 6 and 12 months. An analytical model was developed to determine the degradation of adhesive material, bond and the interfaces of composite exposed to seawater and distilled water. The developed model is in good agreement with test results and capable of predicting initial bond degradation rate and stabilized degradation under-considered exposure conditions. Furthermore, the model could predict the contribution from the interfaces, bond line, and adhesive component on the degradation of composite in service.
item: Conference-Abstract
Bond performance of CFRP/steel composites: state of the art review
Perera, UND; Gamage, JCPH
Over the past decade, CFRP (Carbon Fibre Reinforced Polymer) has been established as an excellent strengthening material to use in the metallic structures. Performance of CFRP strengthened steel members is directly dependent on the quality and the integrity of the adhesive bond. However, the insufficient knowledge on the bond behaviour of the CFRP/steel bonded joints is the major drawback in the lacking of real world applications of this system. Bonding procedure, including the surface preparation, different loading conditions and environmental conditions experienced can critically affect the bond behaviour and its performance. Studies have shown that dynamic loadings (fatigue/impact) can contribute to the strength and stiffness reduction of the bond while aggravating the results in severe exposed conditions. Also, these structures are frequently exposed to environmental conditions such as temperature variations, humidity conditions, UV radiation and marine environment. The consequence is severe when these exposure conditions are combined. This paper presents a state of the art review on bond performance of CFRP strengthened steel members for different load effects.
item: Conference-Full-text
Bond-slip models of cfrp/steel double strap joints subjected to long term exposure of moisture and elevated temperature
(IEEE, 2020-07) Perera, UND; Chandrathilake, ERK; Gamage, JCPH; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
Strengthening of deteriorated steel elements using Carbon Fiber Reinforced Polymer (CFRP) materials is widely gaining appeal. Since the majority of applications can be seen in outdoor structures, the evaluation of long-term behaviour under various environmental conditions is an important aspect. In the present study, the bond performance of CFRP strengthened steel double strap joints immersed in distilled water at ambient (28 oC) and elevated (40 oC) temperatures for six months was examined. A total of twelve specimens were tested including four control specimens and eight number of conditioned specimens. A numerical model was also developed. The model results are in good agreement with experimental results. The bond shear stress – local slip curves were then developed for each environmental condition using model predicted strain readings. The bond-slip models showed a bond shear strength degradation of about 24 % at 28 oC and 30 % at 40 oC within the exposure duration of six months.