**Project:
****Trajectories of particles in sliding contacts.**

**Client:** SKF Engineering & Research Centre B. V.
(The Netherlands)

**Researcher:**
**George
K. Nikas** (Imperial College London, Mechanical Engineering
Department).

**Supervisor: **Dr Stathis Ioannides (SKF and
Imperial College London).

**Project
duration: **1 month (1996).

**Computer
software developed:** program **TRAJECTOR**.
Computation of the trajectories of solid
micro-particles in concentrated bearing contacts. Compiled in Fortran.
Code length: 231 lines. Latest version: 1.1.1. Registered user: SKF.

**Summary**

This project was about the computation of the trajectory of a single particle in a 2-dimensional flat contact, given the distribution of tangential velocities of the contact surfaces. A particle in a flat contact is modelled as a platelet and, because of the surface velocity distribution, such a platelet generally rotates and translates according to the local velocity vectors. An integration is done on the bases of the particle-platelet to calculate the resultant velocity for the particle as a rigid body. Because the surface velocities are known at specific numerical grid points and the grid density may not be sufficiently high for accurate calculations of the particle motion, an interpolation is done among grid points using two methods: bi-linear and bi-cubic interpolation. Then, the velocity integration is carried out and the translation of the particle is calculated, until the particle exits the contact. The aim of this project is to compute the particle trajectory and then to estimate the surface material removed from the abrasive action of the particle.