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Study On Dynamic Modeling And Characteristics Of Flexible Road Wheel

Posted on:2021-06-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y J DengFull Text:PDF
GTID:1522306800977149Subject:Vehicle Engineering
Abstract/Summary:PDF Full Text Request
Tracked vehicles occupy a very important position in ground mobile platforms and play an important role in the military field because of its good passability.Currently,high mobility has become one of the goals of modern tracked vehicle design and research.The road wheel is an important part of the propulsion device of a tracked vehicle and its performance directly affects the maneuverability,passability and smoothness of the vehicle.Aiming at the shortcomings of traditional road wheels,such as low load efficiency,large mass,and poor vibration damping effect,the research object of this paper is a new type of flexible road wheels,which breaks through the rigid solid structure of traditional road wheels,adopts a catenary composite flexible structure,has a high load-bearing efficiency,good cushioning and vibration-damping performance,and great potential in light weight.In this paper,the dynamic modeling and characteristics of flexible road wheels were studied in depth through the combination of theoretical analysis,numerical simulation and experiments,which provides guidance for the research of comprehensive mechanical properties,structural optimization design and matching vehicle performance with flexible road wheels.The main research contents of this thesis include the following aspects:(1)Outlined the composition,function and performance requirements of tracked vehicle driving system,clarified the structural composition,load bearing and movement mechanism of flexible road wheels;formulated the material application plan of flexible road wheels comprehensively considering the cost,performance and light weight.The static model of the flexible road wheel at any angle and the dynamic model of the flexible road wheel under different working conditions were established,which laid a theoretical foundation for the subsequent research on the static and dynamic characteristics of the flexible road wheel.(2)The static performance of flexible road wheels was studied by finite element analysis and material tests.Through uniaxial tensile and dynamic tests of rubber materials,the parameters of the rubber material’s superelasticity and viscoelasticity were identified.A three-dimensional nonlinear finite element model of flexible road wheel/track shoe contact was established.Based on the established finite element model,the overall stress of the flexible road wheel,the stress of the components and the contact pressure distribution were analyzed and the results were compared with those of the rigid road wheel.(3)Combined with numerical simulation and modal experiment,the vibration modal characteristics of the flexible road wheel was studied and the natural frequency and modal array of the flexible road wheel were analyzed.The influence of the key structure and material parameters of the flexible road wheel on the natural frequency was studied by using the orthogonal test design method.Finally,the modal experiment of the flexible road wheel was carried out.The implicit dynamic method was used to study the deformation and contact pressure distribution of the flexible road wheel under different steady-state rolling conditions.The transient dynamic characteristics of the flexible road wheel impacting the trench was studied by explicit dynamic method,and the influence of the impact speed on the center speed,displacement and acceleration of the hub was also analyzed.(4)Integrating the finite element and multi-body dynamics methods,a rigid-flexible coupling model of the flexible road wheel which considers the "flexibility" of the elastic outer ring was established.The motion characteristics of the flexible road wheel under changing conditions were studied,and the changes in hysteresis angle and forces at the hinge joints were studied.The effects of vehicle speed,load,and number of hinge groups on the vertical vibration of the flexible road wheel were studied,which laid the foundation for exploring the mechanism of the flexible road wheel.(5)Based on the static load simulation of the flexible road wheel,a nonlinear model of the flexible road wheel was established and added to a tracked half-vehicle dynamic model.The effect of the nonlinear stiffness of the flexible road wheel on the dynamic response of the track vehicle was analyzed.The smoothness of tracked vehicles that match flexible road wheels and rigid road wheels on random uneven roads were analyzed comparatively,and the impact of road grade and speed was also studied,which provides a reference for flexible road wheels replacing rigid road wheels and matching tracked vehicles.
Keywords/Search Tags:flexible road wheel, mechanical characteristics, dynamic characteristics, rigid flexible coupling model, finite element method, ride comfort
PDF Full Text Request
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