Wind-induced Response Analysis And Control Of Bridge-type Grab Ship Unloader

Bridge-type grab ship unloader is the most important mechanical equipment used for the bulk cargo handling machinery and equipment in the world,Bridge-type grab ship unloader more works on seaside harbor,where has large windward area,concentrated wind action,height of the barycentre,it can produce resonance,fatigue break-down and overturning accident easily.At present,there is no systematic research on dynamic characteristics and wind-induced vibration control of structure on fluctuating wind load.This paper taking the bridge-type grab ship unloader as the object of study,through the finite element simulation software to analysis the response of static wind and fluctuating wind vibration,get the structure characteristic,and based on structure control theory put forward method of wind vibration control,using simulation to assess the effect of Wind-induced vibration control on this method.Using similarity criterion to design the situation of stress-strain on static wind loading of scale model of bridge-type grab ship unloader,and verify the correctness of simulation analysis structure of ship unloader and wind load,before and after the wind vibration control of ship unloader,overall analysis andverification of its overall characteristics of stress strain test of each structure.The main contents of this paper are as follows:(1)Based on mechanical characteristics of metal structures and main technical parameters of bridge-type grab ship unloader at work,make reasonable simplifications on finite element model of ship unloader,and research on characteristics of static wind response under different working conditions and wind speed load in the two directions,know the longitudinal wind load is much larger than the transverse wind load,and make clear the position of stress concentration and maximum displacement of ship unloader.(2)Based on finite element model of ship unloader to make modal analysis and get main vibration modes and natural frequencies under different working conditions,using MATLAB to make numerical simulation of fluctuating wind,and analysis the dynamic time history of excitation of fluctuating wind load under different working conditions,extract the key position stress and position time history curve,and compared with the result of static wind response analysis.The result shows that when the same basic wind speed under the action of fluctuating wind,the maximum stress and displacement greater than static wind action,it need to consider fluctuating wind load during the design of ship unloader.(3)Based on wind vibration control theory of ship unloader,combined with the overall stress-strain structure which obtained by analysis of static wind response and fluctuating wind vibration response of ship unloader,put a wind vibration control method,make the time history analysis of fluctuating wind load of Ship unloader after wind-induced vibration control through the finite element software,compared with the results of wind vibration before control,get the effect of wind vibration control,the results shows that the wind vibration control effect is good.(4)Based on similarity criterion to design and manufacture scale model of ship unloader,make static wind load test of scale model under different working conditions,and compared with the results of finite element model static wind analysis,the results show that the correctness of simplification of the ship unloader by finite element model and the wind load method;At the same time,make comparative analysis of Stress strain test of fluctuating wind load of scale model before and after wind vibration control under different conditions.It shows the correctness of wind vibration control method and the control effect is good.This paper systematically introduces that simplification of finite element model and static and dynamic structural characteristics under static wind and fluctuating wind loads of ship unloader,on this basis,do research of wind vibration control method of ship unloader,the accuracy of the finite element model simplification,wind load loading and wind-induced vibration control is proved by experiments,it provides a theoretical basis for wind-induced vibration analysis and control studies of bridge-type grab ship unloader with different parameters.