| Tire road frictional drag, an important trace in accident site, is the most importantbasis for transportation accident reconstruction.The uncertainty phenomenon of theaccident vehicle tire road frictional drag in the braking (in the case of cars equippedwith ABS) and turning conditions has been caused lots trouble to the experts abouttraffic safety, trace evidence and traffic accident. Analyzing the explicit-implicitcharacteristics of tire road frictional drag and providing a more reliable basis fortransportation accident reconstruction is still an unresolved issue.Considering the vehicle and road as an integrated system, take the study of thedynamic force of tire, tire friction and wear based on the mechanical of road-tiresinteraction. Fully consideration the association mechanical of influence factors, thisarticle mainly study the vehicle-road system dynamic characteristics, resolve theproblems such as the regional determination and the influence factors about theexplicit-implicit characteristics of tire road frictional drag.(1) According to the viscoelastic properties of tire rubber and fractalcharacteristics of rough road, the actual contact mechanical between the roughpavement and rubber is analysized and the rough road dependedce of actual contactmodel is improved based on the contact theory of rough pavement. Considering themechanical between road tire interact, the loss modulus of the rubber material issimplified, an improved sliding friction model which combined with the characteristicof the tires and the road surface is proposed, the variation of the dynamic slidingfriction which is strongly affected by the rubber and rough road features is obtained.(2) The slip velocity in the tire slip region is accurately calculated based on fullyconsideration of the nonlinear characteristics of the carcass and tread. The dynamictire model combined with the rubber features, road surface characteristics, slidingspeed as well as contact pressure is established, the efficiency of the improved modelis verified by the utilization of the Tire Tester in CarSim. Last, the impact of dynamicsliding friction factor, rubber and road surface (mechanics, materials, workingconditions) characteristics on tire dynamic friction force was evaluated quantitatively.(3) Combined with the simplifid tire dynamic friction model and the vehiclenonlinear dynamic model, a new15DOF vehicle-road nonlinear dynamics model isproposed. The detecting system for car handing stability combined braking andturning is integrated with the application of GPRS and inertial measurementtechnology and the model reliability is verified. In order to analysis the explicit-implicit features of tire road frictional drag in systematic, the dynamicparameters of the vehicle in accident is obtained with the application of PC-Crash, theimpact of various factors on the vehicle dynamic parameters and its differencescharacteristics is analyzed.(4) The microscopic mechanism of the tread rubber wear and abrasion isanalyzed; The discrepancy characteristic of tire force is studied combined with thevehicle-road dynamic nonliner model. With the application of the extendminimization, the differences characteristic of friction energy is analyzed inquantitative. Then, through the energy model of tread wear mass, the tread wear andabrasion performance is evalued, an useful insights into solving the explicit-implicitfeatures of tire prints in systematically is proposed. |
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