| Steel structures are widely used in buildings,bridges,mine derricks and offshore engineering because of their unique excellent characteristics.However,if steel structures are placed in the external environment with corrosive media for a long time,it is easy to cause pitting corrosion,resulting in the decline of relevant mechanical properties of steel structures,which will affect the stability of the whole structure and even threaten people’s lives and property.In this paper,the relevant mechanical properties of circular steel pipe subjected to local random pitting corrosion are analyzed through axial compression test and numerical simulation,and the relevant formulas are proposed to reasonably evaluate the residual mechanical properties of circular steel pipe with local random damage,which can effectively avoid accidents.The main conclusions are as follows:(1)The 2L/5 range of the bottom of three kinds of circular steel pipes with slenderness ratios of 18.58,25.20 and 39.22 were treated with different pitting damage degrees respectively,and the corresponding yield bearing capacity and elastic modulus were obtained through axial compression test.The results show that when the slenderness ratio is small,with the increase of pitting corrosion,the yield bearing capacity and elastic modulus of round steel pipe decrease in an approximate first-order function relationship;With the increase of slenderness ratio,the effect of local pitting on the yield bearing capacity and elastic modulus of circular steel pipe is more obvious.(2)Through a parametric modeling method of intersection line,two kinds of models of perfect circular steel pipe and local pitting damage circular steel are established.Through the axial compression test and relevant code formulas,the error analysis of the ultimate bearing capacity of the perfect circular steel pipe model is carried out.The maximum error between the test results and the simulation is 6.44%,while the maximum error between the calculation results of the standard formula and the simulation is only 4.95%.(3)The influence of local random pitting corrosion on the relevant mechanical properties of circular steel pipes with different slenderness ratio is analyzed by ANSYS numerical simulation,which is basically similar to the experimental law.When the damage parameter DOP is 5%and the slenderness ratio of circular tube is 39.22,the yield bearing capacity and elastic modulus degradation rate of circular tube reach the lowest,which are 24.1%and 21.2%respectively.(4)Through strain collection and simulation,it can be found that when the round steel pipe is compressed and does not reach yield,the strain between circumferential adjacent pits is generally less than that between longitudinal adjacent pits in the range of pitting damage.Before the instability failure of the damaged circular steel pipe,the strain changes most significantly in the damage range,followed by the middle of the member.(5)Through the simulation analysis data,the reduction fitting formulas for the yield bearing capacity and elastic modulus of circular steel pipes with different slenderness ratios under the influence of local random pitting corrosion are fitted.The fitting correlation coefficients are 0.993 and 0.997 respectively,and the fitting effect is good.Combined with the test data,the error analysis is carried out.Compared with the test,the maximum errors of yield bearing capacity and elastic modulus calculated by reduction fitting formula are 6.66%and 4.70%respectively.Figure[48]table[10]Reference[58]... |
