Study On The Influence Of Local Damage On Elastic-plastic In-plane Stability Of Steel Tube Arch

Arch because of its excellent mechanical properties and beautiful exterior is finding wider and wider application in the modern structural engineering, and with the rapid development of high strength steel, steel arch structure occupy a large proportion. However,the steel arch structure exposed to external corrosion environment, environmental corrosion causes local damage problems are inevitable, this will reduce the ultimate bearing capacity of arch, seriously influenced the stability and security of arch. This paper based on five vertical symmetrical load, different damage of parabola arch with fixed ends as the research object,adopting the means of model test and numerical simulation carried out the study on the influence of local damage on elastic-plastic in-plane stability of steel tube arch.(1)Experimental study on elastic-plastic in-plane stability of steel tube arch which with local damage. Designing the test which explore the local damage effect on the in-plane elastic-plastic stability of steel tube arch, analysis of fixed ends meet with local damage parabola arch under five vertical symmetrical load current. Trial designs for 11 different damage of steel tube arch specimen and form a complete set of test device and load plan,reference the concept of effective bearing area in damage mechanics to even change the damage location area to simulate the local damage of steel tube arch, real-time tracking the internal force and deformation of arches in the loading procedure.(2)Comparative analysis of numerical simulation and experimental results. On the basis of experiment, considering the influence of the actual specimen geometric imperfections and material nonlinearity, using finite element software Ansys numerical simulation analysis is carried out on the test model. Basing on experimental data and finite element analysis, the calculation results included the load-displacement curve, the load-strain curve, local plastic deformation, internal force distribution and vertical deformation, and contrasting and analyzing test results and finite element calculation results. The results show that the steel use the secondary plastic constitutive model and consider arch axis geometric initial imperfection and wall thickness error, when steel tube arch specimen in elastic stage and the yield stage,the finite element calculation coincides with the test result has higher similarity; The ultimate bearing capacity by finite element is compared with the test, the average error is 3.3%, the finite element analysis can accurately simulate ultimate bearing capacity, internal force and deformation mode of arches in the loading procedure.(3)Parametric analysis of steel tube arch local damage. On the basis of 11 steel tube arch specimen in experiment, using finite element software Ansys to finish a large number of numerical simulation, analyzing damage location, damage length and damage depth,summarized the influence of different damage parameters on the ultimate bearing capacity of steel tube arch. The results show that the influence of damage depth on ultimate bearing capacity of steel tube arch is the most significant, and affects the influence of damage location and damage length on ultimate bearing capacity of arch. Parameters analysis results would provide guidance for further research that on the influence of local damage on elastic-plastic in-plane stability of steel tube arch, and provide reference for detection staff to safety assess steel tube arch bridge with local damage.