Research On Wind Vibration And Fatigue Oftunnel Equipment Under Piston Wind

With the rapid development of high-speed subways in China,the market demand for subway tunnel attachments is increasing.The increase of subway train speed also puts forward higher requirements for the design of subway auxiliary equipment.Scholars at home and abroad have done a lot of research on the aerodynamic effects of high-speed subway tunnels using numerical simulation calculations,model tests,and field measurements.However,the fatigue durability and safety of auxiliary equipment in the tunnel by the piston wind of subway trains have been studied.There are fewer studies on the adverse effects.For this reason,this paper studies the auxiliary equipment in the subway tunnel for the first high-speed subway line in China at a speed of 140 km/h.This paper deduces the piston wind speed of the subway train under constant and unsteady flow of piston wind,outlines the types of ancillary equipment for high-speed subway tunnels,and details the equipment composition structure,installation method and working conditions.Taking auxiliary equipment as the research object,a numerical simulation model is established.Combined with theoretical analysis,a set of simulation methods such as conventional statics,wind vibration dynamic response,unidirectional fluid-solid coupling,two-way fluid-solid coupling and fatigue analysis are used to study the auxiliary equipment for the safe operation of the high-speed subway and the extension of the auxiliary Provide an important guarantee for the service life of the equipment.Firslyt,the results of structural mechanics analysis show that:(1)Under the effect of positive peak pressure and negative peak pressure,the calculated maximum von Mises stress value of the auxiliary equipment is less than the material yield strength,which meets the strength requirements and most have a large margin;(2)The maximum tensile stress of the concrete at the anchorage of the auxiliary equipment is less than 1.54 MPa,which meets the requirements of the "Code for Design of Reinforced Concrete and Prestressed Concrete Structures of Railway Bridges and Culverts";(3)The auxiliary equipment and concrete that are greatly affected by the subway piston wind are: Single air valve,contact net rigid suspension concrete at B anchorage.The changes of stress and displacement of the structure of the single air valve under different opening and closing angles are studied.The influence of the structure parameters of the single air valve on its stress and deformation is analyzed.It provides the serialization,standardization and modularization of the air valve Certain theoretical guidance.Secondly,the one-way fluid-solid coupling method is used to improve the rationality of the load loading of the ancillary equipment.The two-way fluid-solid coupling method is used to make the influence of the deformation of the single air valve structure domain on the fluid domain considered.By extracting the first 30 natural frequencies and vibration modes of the single damper structure,it is found that the vibration mainly occurs on the blade structure.Based on the study of the dynamic characteristics of the tunnel auxiliary equipment and the coupling analysis results,the differences between the various simulation calculation results are compared.The comparison results show that:(1)the structure of the tunnel auxiliary equipment under various simulation methods meets the strength and displacement requirements;(2)Compared with the static analysis of the structure,the transient dynamic calculation results of the single damper have a smaller amplification effect;(3)The static analysis results of the conventional structure are conservative and safest,but the accuracy is poor;unidirectional and bidirectional flow Solid-coupling analysis is closer to the actual situation,and the calculation results are more true,of which the two-way fluid-structure coupling analysis is the most accurate.Finally,the S-N curve expression of the single damper material was deduced using "Steel Structure Design Code"(GB50017-2003),and the material S-N curve was fitted by combining the elastic modulus of the material and the ultimate tensile strength.Based on the SN curve and the linear cumulative damage theory,a professional fatigue analysis module Fatigue tools is used to numerically calculate the fatigue life of the single air valve.The results show that the minimum fatigue life of the structure under conventional wind vibration is cycle;the minimum safety factor is 1.248,Located at the junction of the broken shaft and the blade,it is the same position as the maximum Von Mises stress of the single air valve structure.Compared with the results of conventional wind-induced fatigue analysis,the minimum safety factor of a single damper based on fluid-structure coupling is increased by67.64%.The research ideas and research methods in this paper have certain guiding significance for the design of the auxiliary equipment structure of high-speed subway tunnels.On the basis of improving the safety performance of the auxiliary equipment of the tunnel,the market competitiveness of the products is improved.Provide a certain reference value.