BS ISO 8855:2011 pdf download.Road vehicles – Vehicle dynamics and road-holding ability – Vocabulary.
BS ISO 8855 defines the principal terms used for road vehicle dynamics. The terms apply to passenger cars, buses and commercial vehicles with one or more steered axles, and to multi-unit vehicle combinations.
2 Axis system
2.1 reference frame
geometric environment in which all points remain fixed with respect to each other at all times
2.2 Inertial reference frame
Newtonian reference frame
reference frame (2.1) that is assumed to have zero linear and angular acceleration and zero angular velocity
NOTE In Newtonian physics, the Earth is assumed to be an inertial reference frame.
2.3 axis system
set of three orthogonal directions associated with A land Z axes
NOTE A right-handed axis system is assumed throughout this International Standard, where: Z = Xx).
2.4 coordinate system
numbering convention used to assign a unique ordered trio (x, v, z) of values to each point in a reference frame (2.1), and which consists of an axis system (2.3) pIus an origin point
2.5 ground plane
horizontal plane in the inertial reference frame (2.2), normal to the gravitational vector
2.6 road surface
surface supporting the tyre and providing friction necessary to generate shear forces in the road plane (2.7)
NOTE The surface may be flat, curved, undulated or of other shape
2.7 road plane
plane representing the road surface (2.6) within the Lyre contact patch
NOTE I For an uneven road, a different road plane may exist at each tyre contact patch
NOTE 2 For a planar road surface. the road plane Is coincident with the road surface, For road surfaces with surface contours having a wavelength similar to or less than the size of the tyre contact patch, as in the case of many ride events.
it is intended that an equivalent road plane be determined. Determination of the equivalent road plane is dependent on the requirements of the analysis being performed. The equivalent road plane may not be coincident with the actual road surface at the contact centre (4.1.4).BS ISO 8855 pdf download.