The Research On The Performance Of Tracked Vehicle Under Soft Ground Condition

The tracked vehicle has a special structure,with high ground specific pressure,high tractive force,high load-bearing capacity and other characteristics,which is suitable for long periods of heavy load driving operation on various special substrates.Its driving performance is an important indicator to measure its safety and stability.Based on the theory of track-ground mechanics,this paper conducts geomechanical experiments to obtain geomechanical property parameters and build a geomechanical property model for the soil in the oil tea plantation area of Zhentou Town,Liuyang City,Changsha City,Hunan Province.Combined with vehicle dynamics research,this paper uses the multi-body dynamics modelling and simulation software RecurDyn to build a tracked work vehicle model and carry out multi-conditions driving simulation analysis to study the driving performance of tracked work vehicles on special substrates.The main research and conclusions of this paper are as follows:(1)Soil pressure-sinkage experiment and triaxial shear experiment were carried out on soils from oil tea plantations in Zhentou Town,Liuyang City,Changsha City,Hunan Province.Based on the Bekker model,the pressure-sinkage experiment was carried out,and a specific soil pressure model was constructed,so as to obtain the soil pressure parameters,including the settlement index,cohesive deformation modulus and frictional deformation modulus.Based on Coulomb model,soil shear strength was analyzed and undrained and unconsolidated(UU)tests were carried out.According to the axial strain-principal stress difference data,a specific soil shear model was derived,and shear parameters such as internal friction angle and cohesion force were obtained.These ensure the reliability of simulation substrate model building.(2)Refer to the woodland track work vehicles on the market to establish the track operation vehicle simulation model,and conduct structural analysis and dynamic research.The driving speed,driving resistance,traction force and driving torque of the vehicle were analyzed,and the driving steering process of the vehicle was studied to obtain the theoretical turning radius of the vehicle.The slope driving stability of the vehicle was analyzed to obtain ultimate caster angle for longitudinal slopes and ultimate roll angles for transverse slopes.These provide data support for the verification of virtual prototypes.(3)Multibody dynamics simulation software Recurdyn was used to create vehicleground systems.According to the specific simulation research of flat ground,longitudinal slope,cross slope,turning and obstacle crossing conditions,the vehicle simulation performance parameters were obtained.The simulation data and theoretical data were compared to verify the effectiveness of the simulation.Through multi-condition simulation,it is concluded that the crawler work vehicle has stable straight driving on flat ground under specific soft substrate conditions,and can stably pass the longitudinal slope of 30° working condition,the cross slope of 20° working condition,the vertical wall 100 mm high,and the 400 mm wide trench.When the theoretical turning radius is 1054 mm,the actual turning radius is 1273 mm.It has the basic performance of driving in soft soil conditions in Hunan.This study fully considers the influence of the special characteristics of the substrate on the driving performance of the vehicle,and can accurately evaluate and feedback the safety,stability and passing performance of the vehicle driving operation,which has important application value for the popular development of agricultural and forestry mechanisation and the improvement of tracked vehicles.