Analysis Of Flow Induced Vibration And Damping Measures Of Prestressed Pier Based On The ANSYS

At present,the development trend of hydraulic structure is higher and higher working head,larger and larger flood discharge and very limited structure size,so the pier needs to bear huge gate thrust,and the pre-stressed pier has been widely used.On the one hand,the pre-stressed pier meets the requirement that the design size should not be too large;on the other hand,the pre-stressed pier also meets the requirement that it can withstand the huge thrust transmitted by the gate.As an important discharge structure,the safety and stability of the pre-stressed pier is very important for the normal operation of hydropower station.However,at present,when a large number of high-speed turbulent floods pass through light discharge structures,the vibration of sluice piers,i.e.flow-induced vibration,is often caused.Water accidents caused by flow-induced vibration are frequently reported at home and abroad.Designers should pay attention to them in the design process.Based on ANSYS software and taking a hydropower station located in Xunyang County of Shaanxi Province as the research background,this paper carries out dry and wet modal analysis,dynamic response analysis and vibration reduction and reinforcement measures research on the pre-stressed pier of spillway sluice.The main analysis and calculation results are as follows:(1)Collect the basic information of the research project,determine the required calculation load and working conditions,plan the calculation scope of the model,select appropriate elements through ANSYS software,and establish the three-dimensional finite element model of the pre-stressed pier of the spillway sluice.(2)Based on the finite element theory,the dry and wet modal analysis of the pre-stressed pier model of spillway sluice is carried out.The collected fluctuating water pressure loads are applied to the finite element model,and the dynamic response characteristics of the pre-stressed pier model are calculated by the transient analysis module in ANSYS.According to the relevant standards,the safety and stability of the structure is evaluated.(3)Through the principle of dynamic vibration absorption,appropriate vibration reduction measures are designed.Vibration reduction model is established by ANSYSsoftware.The dynamic response of the pre-stressed pier after vibration reduction is obtained by choosing the most dangerous condition for vibration reduction calculation.The results are compared with the dynamic response of the pre-stressed pier before vibration reduction.The results show that adding dynamic vibration absorber at the end of the pier is a feasible vibration reduction measure.