Study on development of element for FRP flexurally strengthened beam

doi:10.19936/j.cnki.2096-8000.20221128.009

Abstract

Abstract: Paste FRP (Fiber Reinforced Polymer) material at the bottom of the beam can greatly improve the bending stiffness of the beam, thereby reducing the deformation of the beam. In this paper, the stiffness calculation formula of FRP flexurally reinforced beams at different stages is established by the stiffness method, and the stiffness matrix of the FRP flexurally reinforced beam element is derived by the variational method, and the FRP reinforced beam element is established. Based on the basic principle of the finite element method, The numerical software is used to establish the calculation program of FRP reinforced beams, and the related experimental researches are analyzed. The results show that the stiffness calculation method of FRP reinforced beams built in this paper is too large in the stage of reinforcement before yielding after concrete cracking. By calculating the average ratio of the yield displacement test results of FRP reinforced beams to the calculated results in this work, and introducing the reduction factor of 1.377 for calibration, the calculated errors of yield deflection and ultimate deflection are within 2 mm and 8 mm, respectively, and the average errors of yield bending moment and ultimate bending moment are -3.0% and 11.4%, respectively. At the same time, the calculated load-displacement curves of each beam are in good agreement with those of the test. In this paper, the calculation results of FRP reinforced beam elements are of high accuracy, and good analysis results can be obtained, which can provide reference for engineering design.

Key words: FRP strengthened reinforced concrete beam, bending resistance, stiffness matrix, reinforcement

CLC Number:

TB332

XU Tian-cai, MA Sheng-qiang, DAN Dan-hui. Study on development of element for FRP flexurally strengthened beam[J]. COMPOSITES SCIENCE AND ENGINEERING, 2022, 0(11): 63-71.

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