Analysis Of Static And Dynamic Characteristics Of Bottom Horizontal Axis Flip Gate

The bottom horizontal axis flip gate is a new-style gate,which is driven by the hydraulic device,in the water conservancy and hydropower project structure.The gate is mainly composed of the door leaf,bottom horizontal axis,hinge seat,self-lubricating bearing,water stop,arm,hydraulic device,locking device and so on.The hydraulic device exerts a force to the arm and then driving the gate leaf turn around the bottom horizontal axis from the upstream direction to the downstream direction.The new style gate has the advantages of simple structure,good aesthetics,suitable for large span,small opening torque,shorter opening and closing time,high design life and difficult to be deposited.At present,the gate is still in the initial stage of exploration,it is lacking in targeted analytical design theory and related norms.Thus the study on the gate,to explore its response under the load state,could provide the theoretical analysis of the gate for some reference significance and will also be contribute to its promotion and application.The stress and strain state of the gate under the action of water pressure and gate load,the natural frequency of the gate and the response state of the gate under earthquake load were mainly introduced in this paper.Firstly,the three-dimensional model of the gate is created by ANSYS software,and then the load is applied to the gate to calculate.The stress and strain results are analyzed and summarized according to the different constraint spacing,span,panel thickness,bottom horizontal axis thickness and beam flange plate and web size.Secondly,two cases were considered in the modal analysis of the gate.On the one hand,the state of the natural frequency is analyzed by ignoring the influencing factors of water.On the other hand,the natural frequency of the gate is calculated to study its changing law by considering the coupling between the gate and the water,that some different conditions that the gate is in a different water retaining height are set.Finally,the response state of the gate under the action of seismic load is analyzed according to the design response spectrum.After the calculation of ANSYS software,the stress and strain cloud of the gate under the action of water pressure and its own gravity load are obtained.We could get a conclusion that the strength and rigidity of the gate can meet the requirements of the relevant specification.In the connection between the vertical main beam and the bottom horizontal axis,the stress concentration is more likely to occur due to the serious variation of the cross section,but it has little effect on the strength and rigidity of the gate.The constraint spacing,panel thickness,bottom horizontal axis thickness and flange plate and web size of the vertical main beam have a great influence on the mechanical performance of the gate,and the span,flange plate and web size of the horizontal main beam and secondary beam have less impact on the mechanical performance of the gate.When the coupling effect between the gate and the water is taken into account,the natural frequency of the gate gradually decreases with the different water retaining height of the gate.It can be seen that the water has an effect on the natural frequency of the gate,and the coupling between the gate and the water cannot be ignored in the design and analysis of the gate.According to the design response spectrum and 8 degrees fortification intensity,the stress and strain of the gate under the action of the earthquake load do not exceed its maximum allowable stress and deflection limit.The stress concentration is easy to occur in the area near the bottom of the leaf door in the middle of the gate span and it is a relatively weak area.