Design Of Gezhouba 3# Shiplock Miter Gate Vibration Status Monitoring System

As Yangtze River's fast-developing shipping industry in recent years,Gezhouba ship-locks' annual throughput witness a rapid growth.Accordingly,its key role to the shipping function of Yangtze River's golden waterway is increasingly clear.Ship lock gates can experience resonance with the increase of opening and closing frequencies by external forces resulted in the surge,the dynamic water load and the huge water pressure on both sides of the gate body under the working condition of low speed and heavy load for a long time,and the stress concentration may occur when the vibration frequency is equal to the inhere frequency of the gate,which could have devastating impacts on the ship lock gate's structure and navigation safety,and leading to serious social consequences as well as economic losses.However,the approach to monitoring and evaluating large-scale metallic structure,especially the underwater structure vibration status seems increasingly important.In this article,taking the Gezhouba 3#ship lock gate as an example and considering complex underwater conditions,piezoelectric acceleration sensors were used as the detecting element based on the results of modal analysis.The vibration state of top pivot and bottom sealing plate were intensively monitored.And this article compiled a software to collect and process the acceleration information.Consequently,a series of effective outcomes are presented as follow:(1)According to the structure and working process of ship lock gates,and established a three-dimensional mechanical model of gates under opening and closing state.Considering the actual working condition and force case,applied boundary constraint condition,and carried on modal analysis to obtain natural frequency and vibration mode of ship lock gates so that the stress concentration area and the vibration source can be mastered.The results showed that the stress concentration was appeared in the top and bottom povit.(2)In this article,it came up with the general framework and realization method of vibration status monitoring system.The Labview program based on the piezoelectric acceleration sensor and the optical F-P acceleration sensor were designed respectively to collect and display and store real time vibration signals.(3)Vibration signals of the ship lock gate were measured by the piezoelectric acceleration sensor.And were used to calculate the displacement information through the signal processing method.Finally,the results of vibration signal measurement and processing are evaluated.The study illustrated that the vibration state of the top pivot reflects the degree of fluctuation of the gate and the vibration amplitude of the bottom sealing plate reflects its resistance performance and its possibility of breaking off.