A Non-Linear Deformation Model for Particle Impact Process

  • Toivo PAPPEL∗, Priit PÕDRA, Neeme JÄRVPÕLD Department of Mechatronics, Tallinn University of Technology
Keywords: erosion, particle impact, contact pressure, contact deformations

Abstract

Mathematical formulation of the particle impact processes is important in many different areas, such as the assessment of pneumatic transportation efficiency, the development theories of abrasive erosion and material shot peening, etc.
The aim of this paper is to analyse the possibilities of application of a non-linear normal deformation model to the particle impact process. Total and residual indentation depth and the normal force component applied to target material surface in the course of particle impact were calculated by the method above. Maximum pressure on target material, the radius of the impact crater and radial stresses were evaluated. Principal stresses under the impact crater were found.
Analytical results were compared with the experimental data, given in the Gommel’s work, where the restitution coefficient, maximum pressure on target material surface and the residual depth of indentation produced by particle impact were practically measured. The spherical steel particles and the target material with different hardnesses of (285 – 790) VHN and (190 – 725) VHN respectively along with particle velocities of 3 m/s – 70.5 m/s and the impact angle of 90° were used in these experiments. It was shown that in case of soft particles the discrepancy between experimental and calculated results is rather significant. This can be explained by the presence of plastic deformations and respective increase of the contact area in real impacts, not considered in theory. The correlation between the experimental and calculated results is much better in the cases of harder particles. It has been shown that the non-linear normal deformation model is applicable for particle impact processes characterisation under different impact angles in the cases when plastic deformation are avoided during the impact.

Published
2009-03-12
Section
METALS, ALLOYS, COATINGS