Wind-deviation Detection Technique And Numerical Simulation Research Of Railway Catenary In Wind Area

Wind safety of electrified railway catenary in strong wind area is of great significance to the requirement of railway transportation safety and efficiency. A novel visual detection technique to detect the wind-deviation of key positions of contact suspension and transverse vibration of column was presented. Combined with static and dynamic FEM simulation results, as well as the flow field analysis conclusions, wind-deviation response mechanism of catenary was studied with different conditions such as anchor mode.Wind deviation detection of railway catenary based on machine vision method was investigated and achieved. Static detecting points are arranged for column vibration detection and dynamic detecting points were distributed at key positions of contact suspension for wind-deviation detection with the help of area CCD camera set on top of catenary column. Detection of transverse, vertical deviation and rotational angle of contact line, catenary wire and dropper can be realized through target matching at static and dynamic testing points, as well as camera motion compensation of observation datum. As for detection algorithm, target projection feedback model of static point was built under camera coordinate system with the moving camera observation datum. The maximum deflection and rotation angle of column at camera height were obtained based on cantilever beam model under worst wind condition, from which the detecting error structure of datum instability was analyzed. Detecting algorithm of column vibration and absolute wind-deviation of dynamic targets was then constructed and optimized. As for image processing algorithm, automatic threshold segmentation method based on improved RGB characteristic operator and intensity-adaptive color image segmentation based on contrast stretching were presented, both of which had good adaptability to complex illumination conditions and background interference. Target offset and rotation were respectively calculated with area method and geometry method uing the segmented image.Wind-deviation simulation model was studied respectively adopting theory method and numerical simulation. Theoretically, sag and wind-deviation of free hanging system and full-compensated chain suspension system were deduced according to statical calculation based on averaged wind velocity. The wind-deviation theoretical model was modified considering the dynamic dropper reation force along the span. Numerically, a novel finite element model of multi-layered wire strand for catenary system was proposed incorporating both material elasticity theory and geometric compatability, which not only can predict its mechanical behavior precisely, but also can reduce solution degrees in the maximal degree. Geometric nonlinearity equations for flexible, large-spanned cable structure of contact suspension was built. The coupled catenary analyzing system was created considering the constraint relations between contact suspension and support structure, which can reflect different wind-deviation response in different anchor mode. Stochastic wind field was generated using WAWS as input load.Adopting the proposed visual detection technique and numerical simulation model, wind-deviation response of catenary targets and wind-flow structure with topography and geomorphology in site taken into account were futher studied through field test, theoretical calculation, finite element simulation and areodynamical simulation. A series of conclusions were obtained about the wind-deviation response with different working conditions. It can be concluded that the proposed visual detection technology can realize real-time wind-deviation detection at key positions of contact suspension and vibration detection of catenary column in strong wind. The established theoretical and numerical simulation model can be helpful in reflecting the wind-deviation behavior of coupled catenary system, and thus provide data support and technical assurance for electrified railway construction, application and maintanance in wind area.