STUDY ON SHEAR RESISTANCE OF CONCRETE BEAM STRENGTHENED WITH NSM CFRP STRIPS

Abstract

Abstract: At present, most of the research methods for the shear strengthening of concrete beams with near-surface mounted FRP strips (NSM-FRP strips) are experimental research, few of which use finite element analysis, and there is no corresponding code to guide the design. In the relevant design formulas put forward by most scholars, most of the effective strain for FRP are obtained through the direct reduction of its ultimate strength, and some scholars have considered the influence factors on the effective strain Ring, but the calculation result is too large. In order to study the shear behavior of concrete beams strengthened by NSM CFRP strips, and derive the expression of shear capacity of reinforced beams. Based on Abaqus, a T-beam model with NSM CFRP strips was constructed to study the effects of concrete strength, stirrups ratio, shear span ratio, embedding angle and interstitial spacing on the shear resistance of reinforced beams. The effective stress expression of CFRP strip considering the related influencing factors is obtained by regression. And the expression of the shear capacity of the beam strengthened with NSM CFRP strips is established. The results show that the strength of concrete, the shear span ratio, the spacing between the battens and the angle of the battens have a great influence on the shear performance of the strengthened beams, and the ratio of stirrups has a certain influence on the strengthening effect. The results calculated using the shear bearing capacity expression are in good agreement with the relevant experimental values.

Key words: NSM, shear strengthening, concrete beam, FEM, CFRP

CLC Number:

TB332

ZHANG Zhi-mei, XU Yu-qi. STUDY ON SHEAR RESISTANCE OF CONCRETE BEAM STRENGTHENED WITH NSM CFRP STRIPS[J]. Composites Science and Engineering, 2020, 0(8): 89-96.

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