Effects of Adhesive Bond-Slip Behavior on the Capacity of Innovative FRP Retrofits for Fatigue and Fracture Repair of Hydraulic Steel Structures

Abstract

Over eighty percent of the navigation steel structures (NSS) in the United States have highly deteriorated design boundary conditions, resulting in overloads that cause fatigue cracking. The NSSs’ highly corrosive environment and deterioration of the protective system accelerate the fatigue cracking and cause standard crack repair methods to become ineffective. Numerous studies have assessed and demonstrated the use of carbon fiber reinforced polymers (CFRP) to rehabilitate aging and deteriorated reinforced concrete infrastructure in the aerospace industry. Due to the increase of fatigue and fracture failures of NSS and the shortage of research on CFRP retrofits for submerged steel structures, it is imperative to conduct research on the effects of CFRP repairs on NSS, specifically on the adhesive’s chemical bonding to the steel substrate. This was accomplished by developing a new analytical algorithm for CFRP bond-slip behavior, which is based on Volkersen’s contact shear single lap joint (SLJ) connection. The algorithm was validated by experimental results of fatigue center-cracked large steel plates repaired with CFRP patches. The state of stresses at the crack tip are largely influenced by a combination of the crack tip plasticity radius and overall bond surface area.

Experimental fatigue evaluation of underwater steel panels retrofitted with fiber polymers

“…Colombi et al (2003) report that delamination around the crack occurs in an elliptical shape with a width that spans between the plastic zones at either end of a crack and a height that can vary depending on the system properties. Analytical models, such as that used by Lozano and Riveros (2019), can be used to determine the local debonding near the crack. Lozano and Riveros (2019) used results from for validation and found good agreement.…”

“…Analytical models, such as that used by Lozano and Riveros (2019), can be used to determine the local debonding near the crack. Lozano and Riveros (2019) used results from for validation and found good agreement.…”

Fatigue Life Estimation Model of Repaired Components with the Expanded Stop-Hole Technique

“…Many crack repair techniques are available, and some of them are relatively simple to implement, such as bonded composite patches [1][2][3], stop-holes (SH) [4][5][6][7][8][9][10][11], and grinding hammer peening [12][13][14]. However, other repair techniques are not so simple, like pulsed electron beam irradiation, metal crack stitching, vee-and-weld, and laser additive crack cladding [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The choice of repair method depends on various technical and practical factors, with material properties and modelling issues posing significant challenges in the selection process.…”

An Experimental Study on Shear Performance of Adhesive Interface between Steel Plates and CFRP

“…The adhesive interface is the weakest park of CFRP strengthened steel plates, in most cases, the debonding failure of the adhesive interface first occurs in the failure of the components [16][17]. Therefore, studying the mechanical properties of the adhesive interface is important to understand the overall mechanical properties of CFRP strengthened steel structures.…”