Experimental investigation on stiffness and strength of single-lap z-pinned joints in a laminated CFRP stress-ribbon strip

Abstract

Carbon fiber-reinforced polymer (carbon-polymer) is an advanced lightweight composite material with high strength and excellent resistance to corrosion and fatigue. Over the past decades, application of fiber-reinforced polymers has been spread from the aerospace to other branches of industry such as automobile and civil engineering. Unidirectional carbon-polymers have a high potential for replacing steel in tensile members. Recently, the first carbonpolymer stress-ribbon bridge has been constructed in Germany. The non-laminated strip-loop carbon-polymer thin strips were used as the load bearing components in this bridge. In comparison with the laminated components, the applied cables are characterized by a more uniform strain distribution though reduced structural integrity. Alternative jointing technologies of carbon-polymer laminates are considered in this paper with an intention to increase the structural integrity and reliability of the production. Tensile behavior of the single-lap joints was investigated experimentally. Three types of the joints were considered. Adhesive joint was set as the reference. The overlap region of the mechanically fastened joints was produced using 9, 25, or 36 steel needles (z-pins) of 1 mm diameter. The proposed hybrid joints were additionally connected with adhesive increasing the load-bearing capacity of the reference joint up to 230%. Concerning the brittle fracture of the adhesive counterparts, the extended progressive failure process within the hybrid joints is responsible for the improvement.

Experimental and Analytical Investigation of Deformations and Stress Distribution in Steel Bands of a Two‐Span Stress‐Ribbon Pedestrian Bridge

“…Due to the lack of relevant data published in the literature, the present experimental program could be considered as an important reference of the test data of stress-ribbon structures. The obtained results will have an impact on further research dedicated to the development of efficient composite structures [5].…”

“…Monumental engineering structures, particularly bridges, are omnipresent in every society, regardless of culture, religion, geographical location, and economic development [1,2]. The stress-ribbon structural scheme can be considered as one of the most efficient for pedestrian bridges [3][4][5]. A deck (often prestressed concrete slabs) with a catenary shape forms the stress-ribbon structure.…”

Strengthening of Fibre Reinforced Concrete Elements: Synergy of the Fibres and External Sheet

“…In this study, thin steel pins are used to fasten the CFRP sheets. The authors of [30,31] developed this hybrid jointing technology. Basically, on top of the epoxy adhesive, the CFRP sheet is mechanically fixed to the concrete by small steel pins.…”

Investigation on Fracture of Epoxy-Filled Composites by Acoustic Emission

“…Wide industrial application is characteristic for epoxybased polymers. Among many others, recent studies by the authors (Gribniak et al 2014(Gribniak et al , 2015Arnautov et al 2015Arnautov et al , 2016 can be mentioned in this context.…”