Evaluation of Spring Properties of Tire Sidewall under Changes in Inflation Pressure

Tire-Pressure Identification Using Intelligent Tire with Three-Axis Accelerometer

“…That means a change of stiffness will alter the characteristic frequency of the wheel. According to the spring-loaded ring tire model in the vibration model [37,38], the relationship between torsion vibration natural frequency and tire stiffness can be derived as:ftor=12πKθρbl, where f tor is the torsion natural frequency, which can reflect the characteristics of the circumferential vibration; K θ is the rotational spring constant of the sidewall portion per unit length, representing the tire and wheel stiffness; ρ is the density; and b and l are the thickness and half-length, respectively, of the tread ring.…”

“…Another tire model from Akasaka illustrates the relationship between stiffness and tire pressure [39]. The theoretical formula of the rotational spring constant about p is [38]:Kt=g(rB,rc,rD,φD,αD,θ)⋅p+h(h,rB,rD,φD,Vr,Gr), where K t is the rotational spring constant, which is nearly the same as K θ in the spring-loaded ring tire mode; p is the tire pressure; r B , r C , and r D are the tire radius parameters related to special tire positions; φ D , and α D are the angle parameters; θ is the rotational displacement; V r is content rate; G r is the rigidity modulus; and h is the thickness. Equation (2) is used to illustrate the relationship between the stiffness and tire pressure, so there is no need to derive it in detail.…”