Browse Topic: Tires
Unlike internal combustion engine (IC Engine) vehicles, the rapidly growing electric vehicle (EV) market demands tyres with superior yet often conflicting performance characteristics. The increased weight of EVs, due to their heavy batteries, necessitates robust tyres with reinforcement and higher inflation pressure. Conversely, increased wear due to higher initial torque and the need for lower rolling resistance to extend range, combined with the requirement for better grip for improved handling, call for advanced compound and tread pattern designs. EV tyres need to be stiffer, lighter, and low hysteresis, making it very hard to reduce low-frequency (20-200 Hz) interior noise that was previously masked by engine noise. This study investigates the low-frequency (20-200 Hz) structural-borne interior noise performance of EV tyres using both experimental and simulation tools. By wisely tuning the tyre's stiffness, mass, and damping properties, the necessary noise targets can be achieved
Tire noise reduction is important for improving ride comfort, especially in electric vehicle due to lack of engine noise and majority of the noise generated in-cabin is from tire-road interaction. Therefore, the tire tread pattern contribution is one of the important criteria for NVH performance apart from other structurally generated noise and vibration. In this work a GUI-based pitch sequence optimization tool is developed to support tire design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. The key point to be considered in this pitch sequence is that it should be reducing the tonal sound and equally spread i.e., the same pitch cannot be concentrated on one side which may lead to non-uniformity. So, the restriction is that
Model-based optimal control has been widely adopted for vehicular stability enhancement. However, existing schemes still suffer from unmodelled external disturbances such as road adhesion variations, which leads to significant performance degradation. The recent progress in X-by-wire chassis brings promising solution to address this challenge. Utilizing independent steering along with distributed driving systems, this paper proposes a vehicular control programs that actively distribute tire forces in both longitudinal and lateral directions to minimize the impact of external parameter perturbations. Firstly, an adhesion disturbance modeling approach integrating composite slip and single-wheel reachability analysis is developed to accurately characterize the feasible region of tire forces under adhesion disturbances. Secondly, based on the disturbance propagation mechanism, the sensitivity differences of various tire force distribution strategies to key vehicle states are systematically
Tire is the only part of the aircraft that contacts the ground, which not only bears the vertical load and lateral load of the whole aircraft, but also provides adequate ground friction to decelerate the aircraft when braking, so the tires are important parts for aircraft take-off and landing. Besides safety concerns, tire physical properties such as vertical, lateral stiffness as static performance and rolling relaxation length, yawed rolling cornering force as dynamic performance are often required by aircraft manufacturers for analyzing aircraft maneuverability. Besides analysis or similarity by experience from other aircraft projects, tires are often qualified by a number of tests, both static and dynamic, to ensure the safety of tires and acquire tire physical performance data.
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