Study On The Stability Bearing Capacity Of Q420 High Strength X-Bracing Angle Steel

With the rapid development of electric power construction in China,a large number of UHV lines put into use,the application of high-strength angle steel in the design of UHV transmission tower is more and more widely,commonly used as the main and diaphragm material.However,previous studies have shown that X-bracing is an important part of the transmission tower against surface deformation for the transmission tower in the mined out area.Therefore,in the background of the typical UHV transmission line through the mined out area,studying on the calculation method of the stability bearing capacity of high strength angle X-bracing,and analyzing the effect of high strength angle steel on the deformation resistance of UHV transmission tower have important significance.An experimental device for the stability bearing capacity of X-bracing angle steel is developed,the stability bearing capacity of Q420 high-strength single angle steel and X-bracing angle steel was tested by the device,the failure mode,the deformation of the inclined plate and the internal force response of the high strength angle steel are obtained,the effect of different section and different axial load ratios of two bars on the bearing capacity is analyzed.Using ANSYS finite element software,the finite element model with the same cross section was established,the finite element results are compared with the experimental results,which verifies the reliability of the finite element analysis.At the same time,L125×8 is taken as an example,more slenderness ratio,the axial force ratio of the two bar and the position of the intersection point were supplemented by ANSYS,the effects of various factors on the bearing capacity and failure mode of Q420 high strength angle steel are analyzed.Based on the above analysis,the effect of axial force ratio was weakened,the 10 kinds finite element simulation of X-bracing angle steel was increased,based on the results of finite element analysis,a formula for calculating the slenderness ratio of the compression bar under the condition of simultaneous compression and compression-tension is presented,The calculated results of this method was compared with the results of the current domestic and foreign codes and the experimental results,results is shown that the method proposed in this paper is accurate and has enough safety.A typical 1000 kV UHV transmission tower is taken as an example,the finite element model of ANSYS is established,the influence of deformation resistance of UHV transmission tower on different surface deformation under normal operatingconditions was studied,the limit values of surface deformation of UHV transmission tower under different surface deformation,as well as the variation of the internal force and failure models of main failure members under the various surface deformation were obtained.At the same time,the material with different strength is chosen to study the effect of high strength angle steel on the deformation resistance of UHV transmission tower.