Design Of Ship Lock Miter Gate Strain Data Processing System

Yangtze River Gezhouba ship lock gates have experienced low speed and heavy load in the water area environment for a long time.With the increase of opening and closing frequencies and the influence of dynamic water load and huge water pressure on both sides,the stress concentration and relief in local area of ship lock gates will occurred frequently,the hydrodynamic structure of ship lock gates can be destroyed easily as well.When the structural damage come to a certain extent,morbidity and dangerous of gates will be happen which lead to bad impact of navigation and economic losses.To sum up,the approach to monitoring and evaluating the strain condition of large-scale metallic structure has a great significance.In this article,the health condition of 3#tailgate in Gezhouba is controlled remotely.According to structure analysis,strain sensors are deployed in the key area of ship lock gates.These operations realize real-time online monitoring,and achieve a series of effective results.The research contents of this paper can be concluded as follow:(1)According to ship lock gate and its operating principle,the three dimensional model is established.Combining with finite element method,the structure of ship lock gate is analyzed by ANSYS-Workbench software.Next,the stress concentration of ship lock gate operational process is ensured and the theoretical foundation of sensor arrange project is provided.(2)In this paper,it came up with the general framework and realization method of strain monitoring system.And a software combining back-end process control moder and front-end display interface is designed by Labview language.And the real-time collection,transmission,display and store of ship lock gate are realized.(3)This paper adopts arithmetic mean filtering,weighted average filtering and wavelet thresholding to smooth and denoise for stress and strain data.And then the extreme value of stress is calculated.At last,comparing with the allowable stress threshold of ship lock gate structural material,and then determine whether the stress change of ship lock miter gate is within a reasonable range.(4)The frequency and time frequency characters of stress and strain data are analyzed by fast Fourier transform and short time Fourier.And then excitation frequency of each stage tare obtained.At last,the vibration hidden danger in the operational process of ship lock gate is evaluated by comparing with the first six order inherent frequency of ship lock gate.