Study On Local Stability Of Short Column With Eccentric Compression Of Corroded H-beam

Steel structure has the characteristics of high strength,light weight,uniform material,simple manufacture,short construction period and so on.The steel structure in service for a long time will have a serious corrosion phenomenon,so the steel structure section thickness loss,seriously weaken the bearing capacity of the steel structure,while affecting the safety,will also seriously affect the durability of the steel structure.Based on the salt spray environment to obtain the Q345 B hot rolled H section steel as the research object,and from the aspects of materials and components of corroded h-beam short column under eccentric load,the local stability of experimental research,numerical simulation and theory analysis,the method of combining the different corrosion degree of H just short column performance of bearing capacity and failure mode.The main contents are as follows:(1)The corroded h-shaped steel column with corrosion time of 0,3,6,9,12,15 months was obtained through the artificial accelerated corrosion test in the neutral salt fog environment,and the standard specimens were cut off from the steel column for evaluation of corrosion degree and monotonic tensile test,and the influence of corrosion degree and position on the mechanical properties of the material was analyzed.The relationship between failure form,stress-strain curve and mechanical properties of steel and corrosion rate was studied,and the relationship between mechanical properties of corroded steel(elastic modulus,yield strength,ultimate strength)and corrosion rate was established.(2)Through the eccentric compression loading test on 6 H-shaped steel short columns with different corrosion ages,the influence of different corrosion degrees on the bearing performance of steel columns was analyzed.The relationship among buckling failure mode,load-displacement curve,load-strain curve,load-bearing performance index and corrosion degree of steel column is studied.The results show that with the increase of the degree of corrosion,the buckling bearing capacity and ultimate bearing capacity of the steel column gradually decrease,and the specimen may change from strength failure to stability failure,which should be paid more attention to.(3)Finite element software was used to establish the finite element model of H-shaped steel short column corroded with different degrees of rust,and the results were compared with the test results to verify the correctness of the finite element model.Through the parametric analysis of the verified model,the influence of different corrosion positions,corrosion types and different eccentricity on the bearing capacity and failure mode of eccentrically loaded h-shaped steel column was studied.The results show that the failure modes of different corrosion sites,corrosion types and eccentric steel columns are different,and the degree of bearing capacity degradation is also different.(4)According to the results of tests and finite element calculations,the influence of different corrosion forms on the local stability of corroded h-beam short columns is analyzed,and the theoretical formula of bearing capacity of corroded h-beam short columns under eccentric load is established.The results are compared with the experimental data to verify the applicability of the formula.