Study On Fatigue Life And Structural Optimization Of Key Components Of Truss Bridge Inspection Vehicle

As its strong bearing capacity and good maneuverability,truss bridge inspection vehicles are widely used in the maintenance and repair of road bridges and other bridges The second rotator is a key component to adjust the working range of the bridge inspection vehicle between the vertical boom and the basic boom.During the work,the hydraulic motor at the second rotator will produce a large impact at the moment of star-up and shutdown.The fatigue life of the second rotator under this impact load needs to be studied.In addition,the domestic bridge inspection vehicle is still conservative in the boom design.and its structure needs to be optimized to complete their lightweight design.Therefore,studying the fatigue life of the second rotator and the optimization of the boom structure under impact loads has guiding significance for improving the reliability of the bridge inspection vehicle.This paper takes QJ16 truss bridge inspection vehicle as the study object,the research content of this paper are as follows:Firstly,in order to obtain the load time history of the second rotator star-up and shutdown impact process,this article uses the gyroscope angular velocity test system to collect the second rotator angular velocity time history of the bridge inspection vehicle under four conditions,and processes the data to obtain the star-up and shutdown process angular acceleration time historySecondly,parameterized model of the whole vehicle was established to extract the twisting point forces at the four twisting points of the second rotator under the initial working conditions.The system carried out the strain test test on the test point of the second rotator,and verified the simplification of the second rotator model.Then,the fatigue-related theory was introduced.Fatigue life and damage cloud diagram under star-up and shutdown impact load.Finally,for the lightweight requirements of the bridge inspection vehicle boom,the design parameters of the connecting frame and the vertical boom are selected as design variables,and the maximum contact stress at the contact position between the vertical arm and the connecting frame slider and the maximum Y-direction displacement of the vertical arm are used as constraints The minimum vertical boom mass is the objective function,and the optimized vertical boom structure reduces weight by 9.4% compared with the traditional design.The fatigue life research methods and boom optimization schemes proposed in this paper have been used in new products,opening up new ways for fatigue life prediction of key components under bridge loading impact loads,and also providing references for other similar practical engineering problems.