Cornering force

Tire tread element displacement and the resulting cornering force

Cornering force or side force is the lateral (i.e. parallel to the road surface) force produced by a vehicle tire during cornering.[1]

Cornering force is generated by tire slip and is proportional to slip angle at low slip angles. The rate at which cornering force builds up is described by relaxation length. Slip angle describes the deformation of the tire contact patch, and this deflection of the contact patch deforms the tire in a fashion akin to a spring.

As with deformation of a spring, deformation of the tire contact patch generates a reaction force in the tire; the cornering force. Integrating the force generated by every tread element along the contact patch length gives the total cornering force. Although the term, "tread element" is used, the compliance in the tire that leads to this effect is actually a combination of sidewall deflection and deflection of the rubber within the contact patch. The exact ratio of sidewall compliance to tread compliance is a factor in tire construction and inflation pressure.

The diagram is misleading because the reaction force would appear to be acting in the wrong direction. It is simply a matter of convention to quote positive cornering force as acting in the opposite direction to positive tire slip so that calculations are simplified, since a vehicle cornering under the influence of a cornering force to the left will generate a tire slip to the right.

The same principles can be applied to a tire being deformed longitudinally, or in a combination of both longitudinal and lateral directions. The behaviour of a tire under combined longitudinal and lateral deformation can be described by a Traction Circle.

See also

References

  1. ^ Pacejka, Hans B.. Tire and Vehicle Dynamics (2nd ed.). Society of Automotive Engineers. ISBN 0 7680 1702 5. 

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • cornering force — The forces exerted on a tire by the slip angle when moving around a curve. Also see ultimate cornering force …   Dictionary of automotive terms

  • ultimate cornering force — The maximum steady state cornering or side force generated by the tires when a vehicle is driven around a skidpad with the speed increased gradually until if it were increased further the vehicle would slide off course …   Dictionary of automotive terms

  • force — [1] A push or a pull that causes objects to change their motion. [2] It is a vector quantity, with a particular direction and forces must be combined with special vector rules. [3] In the SI (international system of units), it is measured in… …   Dictionary of automotive terms

  • Cornering Brake Control — or CBC is an automotive safety system developed by BMW.[citation needed] It is a further development and expansion of the anti lock braking system, designed to distribute braking force during braking whilst cornering. See also Anti lock Braking… …   Wikipedia

  • cornering stiffness — the negative of the rate of change of lateral force with respect to change in slip angle, usually evaluated at zero slip angle …   Mechanics glossary

  • G-force — (also G force, g load) is a measurement of an object s acceleration expressed in g s. It is proportional to the reaction force that an object experiences as a result of this acceleration or, more correctly, as a result of the net effect of this… …   Wikipedia

  • Bicycle and motorcycle dynamics — A computer generated, simplified model of bike and rider demonstrating an uncontrolled right turn. An …   Wikipedia

  • Motorcycle tyre — A rear motorcycle tyre for street use Studded front tyre with sp …   Wikipedia

  • Bundorf analysis — A Bundorf analysis is a way of describing the characteristics of a vehicle that govern its understeer balance. The understeer is measured in units of degrees of additional yaw per g of lateral acceleration.An imaginary exampleHence the total… …   Wikipedia

  • Weight transfer — In automobiles, weight transfer (often confused with load transfer) refers to the redistribution of weight supported by each tire during acceleration (both longitudinal and lateral). This includes braking, or deceleration (which can be viewed as… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.