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Tire Technology—Recent Advances and Future Trends
Published in Anil K. Bhowmick, Current Topics in ELASTOMERS RESEARCH, 2008
The heart of tweel innovation is its deceptively simple looking hub and spoke design that replaces the need for air pressure while delivering performance previously only available from pneumatic tire. The flexible spokes are fused with a flexible wheel that deforms to absorb shock and rebound with unimaginable ease. Without the air needed by conventional tires, tweel still delivers pneumatic-like performance in weight-carrying capacity, ride comfort, and the ability to envelope road hazards. In tweel, the vertical stiffness (which primarily affects ride comfort) and lateral stiffness (which affects handling and cornering) can be optimized independently of each other, enabling new applications not possible for current pneumatic tires. Tweel is in line with a long-term vision and a step towards innovations.
Naturally Occurring Polymers—Plants
Published in Charles E. Carraher, Carraher's Polymer Chemistry, 2017
Michelin engineers have been at the forefront of constructing airless tires for automotive use, developing the PAX run-flat tires. More recently, they have moved to develop airless tires called Tweel tires. They are a strange-looking tire with inner systems of tread that offer degrees of absorbing shocks. The Tweel offers a combination of soft vertical compliance with stiff lateral resistance. It has a thin rubber tread band reinforced by a composite plastic belt supported with V-shaped polyurethane spokes. It is claimed that the Tweel gives increased tread life and greater lateral stiffness. It appears to be noisy at high speeds.
Study of geometric effects on nonpneumatic tire spoke structures using finite element method
Published in Mechanics Based Design of Structures and Machines, 2022
Ravivat Rugsaj, Chakrit Suvanjumrat
Comparative studies and classification of different NPT spoke structures were reported by many researchers (Aboul-Yazid et al. 2015; Shankar, Fazelpour, and Summers 2015; Kucewicz et al. 2017). There is also a need for systematic design methods for NPT mesostructures with high maximum shear strain before yielding or shear flexure. The size optimization of NPT mesostructures was performed to meet the design requirement of 10% shear flexure at 10 MPa of effective shear modulus. The four mesostructures, which are honeycomb, auxetic, sinusoidal auxetic and newly invented S-shape mesostructures, were studied using selected optimization algorithms, namely the particle swarm, genetic algorithm, and response surface methods (Shankar, Fazelpour, and Summers 2015). The two-dimensional finite element model of NPT was analyzed to study the effects of the spoke structure and shear layer on the tire contact pressure, vertical stiffness, stress, mass, and rolling resistance. The four different spoke structures were modeled based on three types of NPT’s concepts including Michelin’s Tweel, Resilient Technologies’ honeycomb-based NPT, Bridgestone’s concept tire and its variation. The models were also divided into two cases (1) with and (2) without composite shear ring, where the shear ring was found to have a great impact on deformed spoke shapes, especially on contact pressure distribution (Aboul-Yazid et al. 2015). The effect of different spoke structure, which is based on the previously selected NPT concepts such as Tweel, Resilient Technologies’, and Bridgestone’s, was further investigated using FEM. The static radial deflection test was performed and the spoke effects on vertical displacement, deformation, contact pressure, and stress distribution were studied and compared (Kucewicz et al. 2017). While these works give a detailed overview of different spoke structures’ behaviors, the deep analysis based on actual NPT material properties is still required.