Energy absorption during compression and impact of dry elastic-plastic spherical granules |
| |
Authors: | Sergiy Antonyuk Stefan Heinrich Jürgen Tomas Niels G Deen Maureen S van Buijtenen J A M Kuipers |
| |
Affiliation: | 1. Institute of Solids Process Engineering and Particle Technology, Hamburg University of Technology, Denickestr. 15, 21073, Hamburg, Germany 2. Institute of Process Engineering, Otto-von-Guericke-University of Magdeburg, Universitaetsplatz 2, 39106, Magdeburg, Germany 3. Institute for Mechanics Processes and Control Twente, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
|
| |
Abstract: | The discrete modelling and understanding of the particle dynamics in fluidized bed apparatuses, mixers, mills and others are
based on the knowledge about the physical properties of particles and their mechanical behaviour during slow, fast and repeated
stressing. In this paper model parameters (modulus of elasticity, stiffness, yield pressure, restitution coefficient and strength)
of spherical granules (γ-Al2O3, zeolites 4A and 13X, sodium benzoate) with different mechanical behaviour have been measured by single particle compression
and impact tests. Starting with the elastic compression behaviour of granules as described by Hertz theory, a new contact
model was developed to describe the force-displacement behaviour of elastic-plastic granules. The aim of this work is to understand
the energy absorption during compression (slow stressing velocity of 0.02 mm/s) and impact (the impact velocity of 0.5–4.5 m/s)
of granules. For all examined granules the estimated energy absorption during the impact is found to be far lower than that
during compression. Moreover, the measured restitution coefficient is independent of the impact velocity in the examined range
and independent of the load intensity by compression (i.e. maximum compressive load). In the case of repeated loading with
a constant load amplitude, the granules show cyclic hardening with increasing restitution coefficient up to a certain saturation
in the plastic deformation. A model was proposed to describe the increase of the contact stiffness with the number of cycles.
When the load amplitude is subsequently increased, further plastic deformation takes place and the restitution coefficient
strongly decreases. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|