Study On The Degradation Of Flexural Capacity Of High-performance H-shaped Steel Beams Corroded In Bending Section

The replacement of building materials is approaching.With its excellent performance,high-performance steel has become popular in long-span bridge structures,high-rise building structures,marine building structures,and industrial chemical structures.In response to the phenomenon of steel structure corrosion,some scholars have conducted research on its performance.These studies are mostly concentrated on the overall corrosion research of ordinary steel structures or high-performance steel beam structures.In this paper,the team focused on high-performance research in the past.On the basis of this,a bending test study on local corrosion of high-performance steel beams was carried out.This study has high theoretical research value,and also has certain reference value for the evaluation of the residual performance of actual corroded steel structures.The work summarized mainly includes the following:(1)Through the design of 4 Q550E non-thick flange H-shaped high-performance steel beams,electrochemical accelerated corrosion test and local corrosion H-shaped high-performance steel beam bending bearing capacity test were carried out,and the local corrosion degree and position of the bending section were obtained.The evolution law of performance steel beam bearing capacity degradation.(2)Based on the ABAQUS software,the buckle analysis step is used to comprehensively consider the geometric initial defects and residual stresses of the actual processed components,and the simulation results are checked on the basis of selecting the appropriate modal factors and the three-stage material constitutive model.The results are in good agreement with the experimental results.On this basis,through the simulation of beams under different corrosion positions and degrees,the four aspects of load-deflection curve,failure mode,principal stress distribution,and section buckling are analyzed,and the results of different corrosion conditions are obtained.The law of the evolution of bearing capacity degradation and failure mode.(3)Through the analysis of the evolution of the failure modes of different corroded beams,considering the possibility of web buckling failure,based on the GB50017-2017 steel structure design standard section 6.3 gives relevant restrictions on the local buckling design of the web.The load calculation formula of the web buckling beam is deduced.Integrate it with the current standard ANSI/AISC 360-10,and at the same time,take into account the influence of corrosion on the geometric parameters of the beam section,and edit it through matlap software.In this way,under the conditions of known corrosion conditions,the matlap program automatically calculates and screens the beam section type,geometric parameters,and possible failure modes,and finally obtains the ultimate bearing capacity and yield load.(4)Combined with the results of two kinds of ordinary steel beams,the applicability of the bearing capacity model is discussed.At the same time,the influence factors of bearing capacity degradation of corroded beams are analyzed,and the relationship between bearing capacity degradation rate of steel beams and material strength and yield ratio is discussed,and the influence of different plate positions on bearing capacity degradation rate of steel beams is also discussed.