Inflation Analysis And Software Development For Cord-reinforced Aircraft Tire

Aircraft tires,as the key component of takeoff and landing safety,is known as the pearl on the crown of the tire industry.Currently,domestic aircraft tires lag behind in performance and foreign aircraft tires blockade in design technology.Therefore,aircraft tire design is a "bottleneck" technical problem in China,and it is urgent to break through the technical barriers of foreign aircraft tires and develop high performance tires.This paper focuses on solving the material nonlinear problem of approximately incompressible rubber,the geometric nonlinear problem caused by large structural deformation and the finite element modeling of the cordreinforced rubber composite material.Finally,the inflation analysis for cord-reinforced aircraft tires is realized.The detailed works of this paper are as follows:Firstly,the material constitutive models of aircraft tires are established,including the constitutive models of approximate incompressible hyperelastic rubber and linear elastic cord and bead ring.The Mooney-Rivlin model is used to reflect the hyperelastic properties of rubber,and the volume modulus is introduced to reflect the approximate incompressible properties of the rubber.The linear elastic model is used as the material constitutive model of cord and bead ring.The material parameters of the constitutive model are fitted based on the mechanical test data and the corresponding model stability criterion are given,which lay a foundation for the finite element analysis of cord-reinforced rubber.Secondly,the three-field hybrid finite element equation of hyperelastic rubber is studied.Based on the three-field mixed variational principle,the variational equations of displacement,hydrostatic pressure and volume are derived.After linearization and discretization,the finite element equations of hexahedral and pentahedral elements are acquired.When hyperelastic rubber is subjected to pressure loads,the variation of external force with respect to displacement needs to be considered to obtain the modified stiffness matrix and equivalent external load vector.Finally,the numerical solution of the nonlinear finite element equation is given to realize the nonlinear finite element analysis of hyperelastic rubber.Additionally,the finite element solution of cord-reinforced rubber composite is studied.The finite element modeling of the cord-reinforced rubber composite material is firstly carried out.The approximately incompressible hyperelastic element is used as the rubber matrix element,and the cord plane element is used as the rebar to construct the rebar model to analyze the cord-reinforced rubber.Then,the finite element equations for large deformation of cord and rubber are established respectively.Subsequently,the embedded constraint between rubber and cord element is also established to obtain the finite element equations of cord-reinforced rubber.Eventually,the accuracy of the algorithm is verified by examples.Finally,special inflation analysis software for cord-reinforced aircraft tires is developed independently.The solver of the software is developed according to the above theory and methods,and the corresponding software interface of finite element modeling and solving is also designed.Simultaneously,the constitutive fitting module of hyperelastic and linear elastic materials is realized.The material parameters of the constitutive model are obtained by fitting the tensile test data of Bridgestone tire material.Eventually,the inflatable finite element calculation is carried out for the radial aircraft tire of model 1270×455 R22,and the calculation accuracy of the developed software is verified by comparing with the commercial software.It is advantageous to the promotion of domestic tire research and development ability.