Study On Static Model Of Non-pneumatic Tire Contacting With Ground And Its Application On Structure Optimization

Compared with traditional pneumatic tire,non-pneumatic tire(NPT)has significant advantages in many aspects.As main components,the structure design and optimization of shear band and spokes have been the focus of researches.And mechanical models can guide structure design by exploring the deformation characteristics of NPT.In this paper,based on the structure and deformation characteristics,the shear band of NPT is simplified into a circular Timoshenko beam,and the spokes are simplified into circumferentially distributed springs.Differential equations,which describe the deformations of NPT contacting with road,are derived based on the principle of virtual work.And the mechanical model of a NPT with linear spokes is established.The accuracy of the model is verified by the finite element method.Then the model is applied to explore the influence of structure parameters on tire deformation when the NPT is in contact with road.Considering the nonlinearity of spoke stiffness of non-pneumatic tire,the descriptions of the spoke stiffness in former model are modified and a mechanical model of the NPT with nonlinear spokes is established.The solutions of the model are obtained by iterative compensations,and the accuracy is verified comprehensively.The new model contains more structure parameters and material parameters,which can simulate the structure characteristics of the NPT more realistically.An optimization procedure is set up by the application of the established mechanical model,with 205/55R16 as the benchmark tire.In the optimization procedure,a NPT is in static contact with a flat road.The maximum value of the contact pressure is used as the optimization goal.With reference to the MultiStart method in the Matlab global optimization toolbox,a method of "batch calculation + optimization of selected start points" is designed,which can reduce the optimization time without losing the calculation accuracy.The global optimal solution under the current requirements are obtained finally,which can help reduce the difficulty of structure design and the workload of subsequent performance optimization.