Chloride Ion Diffusion Simulation And Equivalent Analysis Method In Reinforced Concrete Members

Chloride ion diffusion in reinforced concrete members is one of the main reasons that affect the corrosion of reinforced concrete members by chloride salts,which affect the durability and service life of reinforced concrete members.In order to solve this problem,the numerical simulation research of chloride ion diffusion in reinforced concrete member was carried out by means of ANSYS in this paper.By means of ANSYS software,the numerical simulation method of chloride ions' diffusion in the reinforced concrete members were set up in the software.And on this basis,the impact of axial load on chloride ions' diffusion process was thoroughly studied.An equivalence relationship is established by simulating the deflection-level cracking of reinforced concrete members after chloride salt erosion by means of virtual load,and a constitutive model of concrete damage under the combined action of load and chloride salt erosion is established based on the assumption of equivalent strain.The following research work is mainly carried out in this paper:(1)The comparative analysis of similarity of heat conduction and chloride ion diffusion process was carried out through the differential equation.The correlation between them was obtained through the derivation of the dimension and the reasonable equivalent of the related parameters is realized with ANSYS.Based on the theory,a numerical simulation method based on The Analysis of Chloride ion diffusion process in reinforced concrete members is proposed by which based on the ANSYS software thermal analysis module,and the two-dimensional numerical simulation of chloride ions in concrete is realized.With reasonable modeling,it is possible to realize the prediction of consideration of chloride ions when the reinforced concrete members of any cross-section shape are attacked by chloride ions at a single boundary or multiple boundaries while considering the existence of rebar.By comparing the test data with the analytical solution,nevertheless,method of the simulation is proved to be valid.(2)The continuous load will change the chloride diffusion coefficient of concrete.On the basis of above numerical method,this paper introduces the relational model between the load and chloride ion diffusion coefficient.In ANSYS,the one-to-one correspondence of different concrete cell volumetric strain and chloride diffusion coefficient model is realized through APDL language.And the effective analysis method of chloride ion erosion under different working conditions is proposed under thecoupling effect of load and chlorine.(3)Using the ANSYS thermal analysis module to obtain the erosion of the reinforced concrete members with the change of chloride ion concentration over time,according to the above situation,the corresponding model is used to obtain the change of the material parameters and the rust expansion force.After the cracking deflection of the reinforced concrete member,the method of directly applying a load to the model is used to simulate the same cracking deflection.The simulation results prove that the cracking state of the two models is the same when the same deflection is generated,which can prove the virtual load,etc.The effective method is established.(4)This paper analyzes the experimental data of concrete uniaxial compression under load and chloride erosion,summarizes the effects of chloride salt erosion on concrete stress-strain curve and concrete elastic modulus.Based on damage mechanics of concrete,we established constitutive equations of concrete which is uniaxial compression under load and chloride erosion.The above data verified The constitutive equation established in this paper can well fit the stress-strain curves of concrete uniaxial compression under loading and chloride erosion.