AN ORTHOGONAL UNIFORM/PARABOLIC SURFACE PRESSURE HALF-SPACE ELEMENT FOR THE ANALYSIS OF NON-HERTZIAN CONTACT
An orthogonal uniform/parabolic surface pressure half-space element is derived for the analysis of non-Hertzian contact. Restriction is made to parabolic variation of the surface gap in the contact in one orthogonal direction. The surface pressure is integrated analytically over the surface element to obtain influence co-efficeints, e.g. for the normal surface displacement. The coefficients are assembled into matrices leading to a linear system of equations. After solving the parabolic pressure variation is transformed to an equivalent semi-elliptic one coinciding with Hertzian line contact. Adjustments are introduced to approximate the finite size of the bodies in contact. The theoretical predictions are compared to experiments involving the non-Hertzian contact between cylinders of finite lengths.
A contact problem for the elastic quarter space
Abstract The problem of the contact between a smooth, rigid indenter and an elastic quarter space is solved using integral transform techniques. The indenter can have an arbitrary plan form and can extend to the edge of the quarter space. Numerical results are given when a rigid, right-circular body is pressed into the top surface of the quarter space, while keeping its axis parallel to the surface and perpendicular to the edge.
State estimation for integrated vehicle dynamics control
This paper discusses a vehicle controller and a state estimator that was implemented and tested in a vehicle equipped with a combined braking and chassis control system to improve handling. The vehicle dynamics controller consists of a feed forward body roll compensation and a feedback stability controller. The estimator is based on a non-linear vehicle model combined with an extended Kalman filter. The Kalman filter is also connected to an algorithm, which estimates the tyre-road friction coefficient. The developed estimator was tested in a vehicle. Good results were achieved for normal and extreme driving manoeuvers.