Study On Dynamic Response Of Mine Headframe With Double Backstay Under Normal Working And Rope Breaking Accident

The mine headframe with double backstay is an important carrier for upgrading coal,ore,equipment and personnel during coal mine production.The main bearing members are columns of backstay.The columns of backstay are usually designed with box section and a large number of stiffeners are provided.Uneconomical design can also lead to cumbersome construction techniques.At present,most researches on mine derricks are based on static research.In fact,the tension of the wire rope will fluctuate during the lifting and lowering of the mine headframe lifting system,that is,the mine headframe will be excited by vibration under normal working conditions.At the same time,the broken rope load is usually used as the control load in the mine headframe design,and the force of mine headframe is generated when the rope breakage occurs.It will rise sharply and then unload,which is a typical impact load.At present,there are few studies related to dynamic response of the double sloping mine headframe.Therefore,for the mine headframe with double backstay,the local buckling strength of the backstay column is used to study the dynamic response under normal working conditions and rope-breaking accidents,and the corresponding power amplification factor is obtained,which makes the mine headframe design more economical and reasonable.Simplify the construction process and design process,and have practical application value.This paper uses ABAQUS finite element software and MATLAB programming to establish a finite element analysis model,and carries out the following research work and draws relevant conclusions:?1?Considering the initial geometric defect combination of the columns of backstay and the residual stress of the main columns of backstay,the parameters of the main columns of backstay of the mine headframe in Gansu are optimized,and the static analysis data confirms the rope load.Feasibility of using post-buckling strength of diagonal strut.?2?Considering the change of the quality of the wire rope,the differential equation of tension in the rope under lifting and lowering conditions is given.The tension differential equation is simulated by Matlab-Simulink,and the numerical solution is obtained.The dynamic response of the mine headframe under working condition is analyzed and evaluated.The results show that the vibration in the three directions of the upper and lower sheave wheel loading points of the mine headframe under the action of gravity and working vibration excitation is the strongest at the initial stage of the lifting system,but it tends to be gentle.The maximum amplitude of displacement during the whole process is far less than the specification limit,and the component stress is at a reduced level.No component enters the yield and meets the requirements of the lifting process and bearing capacity.And give the recommended value of the horizontal X-direction displacement dynamic amplification factor of the sheave wheel loading point under normal working conditions.?3?The broken rope excitation is simplified to triangular pulse excitation,and the variable duration analysis is carried out for the pulse excitation,and the dynamic response of the mine headframe under the broken rope accident is studied.The results show that the horizontal X-direction of the upper sheave wheel is significantly larger than the Y and Z-direction displacements when the upper and lower sheave wheel rope breaks,but it is still less than the standard limit.When the rope of upper sheave wheel breaks,the horizontal X-direction displacement amplitude of the upper and lower sheave wheel appears at t_d/T₂=1;when the lower sheave wheel breaks,the displacement amplitude of the upper sheave wheel appears at t_d/T₂=1.25.The displacement amplitude of the lower sheave wheel appears at t_d/T₂=0.1.In the event of a rope break in the derrick,only the plastic tensile strain near the four corners of the main inclined strut and the plastic compressive strain in the center of a few plates are present,and no plastic cross-section is produced by full-section yielding.Finally,considering the most unfavorable influence,the horizontal X-direction displacement dynamic amplification factor of the sheave wheel loading point under the rope breaking excitation is given.