Experiment And Simulation Study On Bond Slippage Of Longitudinal Reinforcement Of Beam Embedded In Joint

Reinforced concrete middle beam-column joint of frame structure under theinfluence of strong earthquake ground motion, through the joints section of the beamreinforcement bar generally in the end of the tensile yield different degree ofcompression while the other end but not yield stress, alternating with tension andcompression stress caused yield penetration and damage of concrete, the node area ofbeam steel bond stress environment will become more bad. Node area after beamlongitudinal reinforcement yield, area this kind of nonlinear deformation caused by thebeam end deflection is not to be ignored, so you need to node area beam accuratelydescribe the stress-slip curve of longitudinal reinforcement bar.This paper mainly completed the following research work:①According to the collected domestic39the middle tier of the reinforcedconcrete plane frame intermediate node test data, using SPSS statistics software tomodel regression analysis of influential factors were significant analysis, get thedrawing test needs to be addressed in the significant influencing factors. ThroughOpenSees program software to simulate the node test analysis, to calculate the axialcompression ratio for drawing test.②Collected according to the university of Berkeley’s17about node centre silllongitudinal reinforcement stress and slip curve of specimen research data, using the moLin Hui model simulation analysis, the test results and simulation results were analyzed.③Design test apparatus and added to the processing factory production, a total of23specimens have been tested on the research, one by one to test results and thecorresponding simulation results contrast analysis, evaluate the Mo Lin Hui stress-slidmodel.The main conclusions are as follows:①Mo Linhui stress-slid model to simulate the middle tier of the reinforcedconcrete plane frame intermediate node stress and slip curve is relatively close to, butmust see that the stress-or slightly conservative slip model.②In this paper, the testing scheme exclusively in measuring slip of longitudinalreinforcement relative to the concrete, relative measurement results are more accurate.Test results of this paper can preliminary judgment, the node test to slip is larger.③Steel yield strength and the influence of the relative anchorage length of the model was the most obvious, under the same conditions, the higher the steel yieldstrength, the shorter the relative anchorage length, the poor, the greater the bondproperties of steel and concrete, reinforcement of slippage. Mo Lin Hui stress-slidmodel is currently not fully reflect the influence of relative throughout the length (hc/d)needs to be added to improve after the test data.