Influence of Mechanical Properties of Steel and CFRP Tapes on the Effectiveness of Strengthening Thin-Walled Beams

Abstract

The paper presents a comparison of the effectiveness of strengthening steel thin-walled, cold-formed sigma beams with CFRP tapes and steel tapes. For this purpose, three beams without reinforcement (reference beams) of the “Blachy Pruszyński” type, with a cross-section of ∑200 × 70 × 2 and a span of 280 cm, made of S350GD steel grade, were subjected to laboratory tests in the four-point bending scheme. In the next stage the tests included nine ∑200 × 70 × 2 beams reinforced with Sika CarboDur S512 CFRP tape and six ∑200 × 70 × 2 beams reinforced with steel tape made of S235 steel grade. The length of the reinforcement tapes as well made of steel as well of CFRP was of 175 cm. The location of the tapes within the height of the beams’ cross-section was assumed in three variants, namely placing the tape on the upper or bottom flange and on the web. In the case of beams reinforced with CFRP, three beams were tested for each reinforcement location, and in the case of beams reinforced with steel tapes, two beams were tested for each reinforcement location. SikaDur®-30 glue with a thickness of 1.3 mm was used in order to connect steel or CFRP tapes to the beams. The dimensions of the tapes cross-sections in both cases were similar (CFRP tapes: 50 × 1.2 mm, steel tapes: 50 × 1.3 mm). For all types of beams, numerical models were also developed in the Abaqus software. The main aim of this paper was investigation of the influence of mechanical properties of steel or CFRP tapes on the effectiveness of strengthening ∑ beams. For this purpose a comparison of these two solutions with respect to the limitation of displacements and deformations of the beam was performed. The obtained results were considered in the context of the mechanical properties of the materials composing the reinforcement tapes. The tests showed slight differences in the results of strain and displacements obtained for reinforcement made of two different materials. It was also noted that the decisive element was the failure of the joint at the steel-glue interface. Therefore, future studies will pay particular attention to the adhesive layer.

Investigation of an Effective Anchoring Length of CFRP Tapes Used to Strengthen Steel Thin-Walled Beams with a Rectangular Cross-Section Subjected to Four-Point Bending

“…The material parameters of a steel beam made of a rectangular section profile were described using an elastic–plastic material model (material parameters are presented earlier at the stage of the description of the subject of research). The material data used in the analysis, both for the composite tape and the adhesive, were taken from [ 1 , 20 ].…”

Influence of Adhesive Layer Thickness on the Effectiveness of Reinforcing Thin-Walled Steel Beams with CFRP Tapes—A Pilot Study

“…The adhesive layer and the composite tape had data adequate in comparison to the information presented in a thematically similar scientific publication [ 13 ]. Material data for the composite tape and adhesive were taken mainly from [ 14 ].…”

Shell-to-Beam Numerical Homogenization of 3D Thin-Walled Perforated Beams

“…Homogenization techniques enable the modelling of very detailed geometries, for instance with regular holes along the member [ 20 , 21 ]. It should be underlined that often the structures are successfully considered as full-shell finite element (FE) models with elaborate geometric complexity; for instance, see [ 2 , 22 , 23 ]. However, applying homogenization techniques enable speeding up of the computations, for instance in optimization processes [ 21 , 24 ].…”