Study On Plastic Hinge Length Of Reinforced Concrete Column

The reinforced concrete frame structure will generate plastic deformation under theaction of earthquake.While the plastic deformation is mainly concentrated on the plastichinge.Therefore, many scholars should emphasis on it. Since the1950s,many formulas ofplastic-hinge length have been proposed on the basis of test by scholars. However,due to thedifferent experimental factors,the formulas used parameters is different. Some importantparameters were not reflected in it, such as fcet al. So considering the main affecting factorsof the plastic hinge length,to establish a more accurate and wider formula is one of theimportant issues need to be lucubrated.The paper takes RC columns as the research object.Firstly, Use of the OpenSeesnumerical simulation analysis of RC columns, contrast experimental results and simulationresults to verify the accuracy of the program to simulate.It comparative analysis of theformula of plastic hinge length on the basis of OpenSees and test data.Secondly,it determinethe main factors of the plastic hinge length.According to the analysis result,a formula can beprovided on the basis of least squares method.The main content is as follows:①Use of OpenSees Beam With Hinges Element and Nonlinear Beam Column Elementare numerical simulation analysis the RC columns.Concluded:Beam With Hinges Elementmore accurate than Nonlinear Beam Column Element;②The accuracy and applicability of the formulas are analyzed by OpenSees and testdata comparison.Concluded: mostly formulas of plastic-hinge length are scope small andsome parameters may not be reflected in it, such as fc;③The affecting factors of plastic hinge length are significant analysis.Concluded:themain factors is L、d、fc、fy;④The formula of plastic-hinge length are provided on the basis of least squaresmethod.Test the suggested model by experimental data of49reinforced concretecolumns.The result shows that: the average value is1.06,while the variance is0.056. Furtherbased on OpenSees, have numerical simulation comparative analysis on plastic deformationcapacity of RC columns of the original model and the suggested model．The research results show that: hysteresis curve of suggested model has better tally with test result.