Numerical Analysis Of Plastic Hinge Lengths Of 600MPa High Strength Reinforced Concrete Column

High strength steel bars are able to reduce the quantity of steel per unit and save nature resources,and make use of steel and concrete materials to build high strength reinforced concrete structures will be an important trend in the future construction engineering structures,the 600 MPa high strength steel bar has great strength,ductility and plasticity,it has a wide application prospect.All the time,intensience-based seismic design has always been the mainstream of design codes around the world all the time,but some disasters caused by earthquakes show that reinforced concrete columns with good deformation capacity is an effective method to prevent the destroy of building structures.At the moment,more countries begin to carry out seismic design according to ductile seismic theory,by analyzing and calculating,plastic deformation of specific parts forms plastic hinges,the seismic energy is absorbed and dissipated by rotation to ease the earthquake injure to the architecture.As the main energy-consuming part of the architecture,plastic hinge not only affects the deformation of the structure,but also promotes the redistribution of internal forces.the plastic hinge length is not only an significant element for the plastic devise and ductility design of concrete structures,but also an important reference for the seismic reinforcement of structures.In this paper,the effects of different parameters on the plastic hinge length and ductility performance of 600 MPa high-strength reinforced concrete columns are studied by finite element simulation,which provides a basis for the ductile seismic design of concrete structures equipped with 600 MPa high-strength reinforced concrete columns.The main work is as follows:First of all,based on the analysis of ABAQUS platform built up the finite element analysis model of high strength reinforced concrete column,through compare the feature of damage state,ductility,hysteretic curve parameter values and the plastic hinge length of test to prove the applicability of finite element model building way,parameter setting in the article,and the longitudinal reinforcement yield way,concrete crushing zone way to judge plastic hinge length with sufficient accuracy and feasibility.Secondly,through the finite element simulation analysis of 25 high-strength reinforced concrete columns of 600 MPa with different parameters under low cyclic load,the effects of axial compression ratio,shear span ratio,concrete strength,longitudinal reinforcement ratio,volume stirrup ratio and other parameters on the plastic hinge length of columns were studied.By comparing the calculated value of the proposed calculation formula for plastic hinge length with the simulated value,the fitting model was set up.Multiple linear regression analysis was conducted on the finite element simulation data of plastic hinge length,and the suggested formula for the calculation of plastic hinge length of 600 MPa high-strength reinforced concrete column was given.Finally,based on the column displacement curvature relations,through the conversion as a plastic hinge length calculation formula of curvature ductility coefficient is an important intermediate variables,and using the plastic hinge length ductility coefficient in the process of simulation results with the finite element simulation calculation for the relevant data such as yield displacement and ultimate displacement,calculate the curvature ductility coefficient,the displacement ductility coefficient and ductility index such as limit displacement Angle analysis of ductility performance and its influencing factors.