Structural Dynamics Analysis Of Shipboard Tube Valve System Under Shock And Sway Load

The ship steam power system provides the necessary steam power medium for the ship,and its subsidiary pipes and valves have the characteristics of high center,long line and uneven mass distribution.The power system is easy to fail under the influence of shock and swing excitation load.If the failure occurs lightly,it will cause the loss of power of the ship,and the heavy will threaten the safety of the ship personnel.Therefore,it is of great significance to study the dynamic response characteristics of shipboard pipe valve system under shock swing load and put forward effective protective measures to improve ship safety.This paper takes the check valve in the steam power system of a ship and the pipeline system connected with it as the research and analysis object,and uses the theoretical derivation,numerical calculation and experimental research means to explore the dynamic response characteristics of the check valve and pipeline system used in the ship under the shock swing load.The main contents of this paper are as follows:(1)Based on the importance of check valves and piping systems for ships,the factors and serious consequences of damage caused by check valves for ships under shock swing load are analyzed.Based on the research methods and research status of external excitation load for ship and ship equipment at home and abroad,the research methods and research ideas for dynamic response of ship check valve and its pipeline system under shock and swing load are put forward.(2)Using the existing seismic test bench,the small tube valve system experimental device was designed and the related tests were completed.The device adopts two experimental schemes: pipe valve structure and pipe valve load-bearing structure,and carries on the characteristic parameter experiment of acceleration and impact to the small model system.Experiments show that changing the mass distribution of pipe valve structure can effectively reduce the impact acceleration of the device under shock swing load.(3)The ANSYS software is used to simulate the experimental device of the small tube valve system,and the numerical simulation results are compared with the test data of the test table to verify the reliability of the numerical simulation method and the correctness of the boundary condition setting.This research lays a foundation for the simulation of the subsequent actual model.(4)The free mode and the constrained mode of the pipe valve system are analyzed by ANSYS Workbench software.The influence of different constraints on the modal mode of the pipe valve system is analyzed.It is found that the torsional deformation of the valve pipe system increases gradually with the increase of the modal order.Based on the modal analysis,the harmonic response analysis is carried out,the structural strength of the pipe valve system is studied and analyzed,the results show that increasing the cross-sectional area of the rocker can reduce the vibration response of the pipe valve system.(5)Based on the theory of rocking numerical analysis and calculation,the mathematical model of linear and nonlinear rocking motion of pipe valve system is established,and the equations of linear and nonlinear rocking motion of the system are solved,and the rocking inertia load is introduced.The influence of swing load on structural strength and shape variables of check valve and tube valve system is analyzed.The results show that the maximum stress produced by the tube valve system is basically the same when the rolling period of the tube valve system is the same.