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Traction (engineering)
Traction, traction force or tractive force is a force used to generate Motion (physics), motion between a body and a tangential surface, through the use of either dry friction or shear force. It has important applications in vehicles, as in ''tractive effort''. ''Traction'' can also refer to the ''maximum'' tractive force between a body and a surface, as limited by available friction; when this is the case, traction is often expressed as the ratio of the maximum tractive force to the normal force and is termed the ''coefficient of traction'' (similar to coefficient of friction). It is the force which makes an object move over the surface by overcoming all the resisting forces like friction, normal loads (load acting on the tiers in negative ''Z'' axis), air resistance, rolling resistance, etc. Definitions Traction can be defined as: In vehicle dynamics, tractive force is closely related to the terms tractive effort and drawbar pull, though all three terms have different definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitude (mathematics), magnitude and Direction (geometry, geography), direction of a force are both important, force is a Euclidean vector, vector quantity. The SI unit of force is the newton (unit), newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include Elasticity (physics), elastic, frictional, Normal force, contact or "normal" forces, and gravity, gravitational. The rotational version of force is torque, which produces angular acceleration, changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtexture
Road surface textures are deviations from a planar and smooth surface, affecting the vehicle/tyre interaction. Pavement texture is divided into: microtexture with wavelengths from 0 mm to , macrotexture with wavelengths from to and megatexture with wavelengths from to . Microtexture Microtexture (MiTx) is the collaborative term for a material's crystallographic parameters and other aspects of microstructure: such as morphology, including size and shape distributions; chemical composition; and crystal orientation and relationships While vehicle suspension deflection and dynamic tire loads are affected by longer wavelength ( roughness), road texture affects the interaction between the road surface and the tire footprint. Microtexture has wavelengths shorter than 0.5 mm. It relates to the surface of the binder, of the aggregate, and of contaminants such as rubber deposits from tires. The mix of the road material contributes to dry road surface friction. Typically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equilibrium Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. Tides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-lock Braking System
An anti-lock braking system (ABS) is a Automotive safety, safety anti-Skid (automobile), skid Brake, braking system used on aircraft and on land motor vehicle, vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maintaining Traction (mechanics), tractive contact with the road surface and allowing the driver to maintain more control over the vehicle. ABS is an automated system that uses the principles of threshold braking and cadence braking, techniques which were once practiced by skillful drivers before ABS was widespread. ABS operates at a much faster rate and more effectively than most drivers could manage. Although ABS generally offers improved vehicle control and decreases stopping distances on dry and some slippery surfaces, on loose gravel or snow-covered surfaces ABS may significantly increase braking distance, while still improving steering control. Since ABS was introduced in production v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tire Wear
A tire (North American English) or tyre (Commonwealth English) is a ring-shaped component that surrounds a Rim (wheel), wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide Traction (engineering), traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface. The materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric, and wire, along with carbon black and other chemical compounds. They consist of a tire tread, tread and a body. The tread provides Traction (engineering), traction while the body provides containment for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siping (rubber)
Siping is a process of cutting thin slits across a rubber surface to improve traction in wet or icy conditions. Siping was invented and patented in 1923 under the name of John F. Sipe. The story told on various websites is that, in the 1920s, Sipe worked in a slaughterhouse and grew tired of slipping on the wet floors. He found that cutting slits in the tread on the bottoms of his shoes provided better traction than the uncut tread. Another story is that he was a deckhand and wanted to avoid slipping on a wet deck. Tires John Sipe's invention was unsuccessful. It was applied to solid rubber tires, rather than pneumatic tires, and so the tires had poor wet grip anyway, owing to their limited contact patch. It was his son, Harry E. Sipe, who popularised the use of sipes in the US for the new low-pressure balloon tires around 1939. The process was not applied to vehicle tires on a large scale until the 1950s, when superior tread compounds were developed that could stand up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Patch
The contact patch is the portion of a vehicle's tire that is in actual contact with the road surface. It is commonly used in the discussion of pneumatic (i.e. pressurized) tires, where the term is used strictly to describe the portion of the tire's tread that touches the road surface. The term “footprint” is used almost synonymously. Solid wheels also exhibit a contact patch which is generally smaller than the pneumatic “footprint”. Contact patch size The contact patch is the only connection between the road and the vehicle. Pneumatic rubber tires The size and shape of the contact patch, as well as the pressure distribution within the contact patch, are important to the ride qualities and handling characteristics of a vehicle. Since the wear characteristics of tires is a highly competitive area between tire manufacturers, a lot of the research done concerning the contact patch is considered highly proprietary and, therefore, very little is published on the subject. Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-track
A half-track is a civilian or military vehicle with wheels at the front for steering and continuous tracks at the back to propel the vehicle and carry most of the load. A half-track combines the soft-ground traction of a tank with the Car handling, handling of a wheeled vehicle. Performance The main advantage of a half-track over a fully-wheeled vehicle is that its tracks reduce the pressure on any given area of the ground by spreading the vehicle's weight over a larger area, giving it greater mobility over soft terrain like mud and snow. A further advantage is that it does not require either the tank steering systems, complex steering mechanism of a fully tracked vehicle or skill in tracked steering, relying instead on a familiar steering wheel connected to its front wheels to direct the vehicle; maneuverability is augmented in some cases by track braking tied to the steering wheel. The main disadvantage is the increased maintenance to maintain track tension, and the reduced l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Track
Continuous track or tracked treads are a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tyres on an equivalent vehicle, enabling continuous tracked vehicles to traverse soft ground with less likelihood of becoming stuck due to sinking. Modern continuous tracks can be made with soft belts of synthetic rubber, reinforced with steel wires, in the case of lighter agricultural machinery. The more common classical type is a solid chain track made of steel plates (with or without rubber pads), also called caterpillar tread or tank tread, which is preferred for robust and heavy construction vehicles and military vehicles. The prominent treads of the metal plates are both hard-wearing and damage resistant, especially in comparison to rubber tyres. The aggressive treads of the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drifting (motorsport)
Drifting is a driving technique where the driver purposely Understeer and oversteer, oversteers, with loss of traction, while maintaining control and driving the car through the entirety of a corner or a turn. The technique causes the rear slip angle to exceed the front slip angle to such an extent that often the front wheels are pointing in the opposite direction to the turn (e.g. car is turning left, wheels are pointed right or vice versa, also known as opposite lock or Countersteering#Other uses, counter-steering). Drifting is traditionally performed using three methods: clutch kicking (where the clutch is rapidly disengaged and re-engaged with the intention of upsetting the grip of the rear wheels), weight transfer (using techniques such as the Scandinavian flick), and employing a handbrake turn. This sense of ''drift'' is not to be confused with the ''four wheel drift'', a classic cornering technique established in Grand Prix motor racing, Grand Prix and sports car racing. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Chains
Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide increased traction when driving through snow and ice. Snow chains attach to the drive wheels of a vehicle or special systems deploy chains which swing under the tires automatically. Although named after steel chain, snow chains may be made of other materials and in a variety of patterns and strengths. Chains are usually sold in pairs and often must be purchased to match a particular tire size (tire diameter and tread width), although some designs can be adjusted to fit various sizes of tire. Driving with chains reduces fuel efficiency, and can reduce the allowable speed of the automobile to approximately , but increase traction and braking on snowy or icy surfaces. Some regions require chains to be used under some weather conditions, but other areas prohibit the use of chains, as they can damage road surfaces. History Snow chains were invented in 1904 by Harry D. Weed in Canastota, New York. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tire Tread
The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded. The word tread is often used casually to refer to the pattern of grooves molded into the rubber, but those grooves are correctly called the tread pattern, or simply the pattern. The grooves are not the tread, they are in the tread. This distinction is especially significant in the case of racing slicks, which have much tread but no grooves. Tires Street tires The grooves in the rubber are designed to allow water to be expelled from beneath the tire and prevent hydroplaning. The proportion of rubber to air space on the road surface directly affects its traction. Design of tire tread has an effect upon noise generated, especially at freeway speeds. Generally there is a tradeoff of tread friction capability; deeper pattern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
