CERES > School of Applied Sciences (SAS) > Staff publications - School of Applied Sciences >

Please use this identifier to cite or link to this item: http://dspace.lib.cranfield.ac.uk/handle/1826/6186

Document Type: Article
Title: Theoretical analysis of the spatial variability in tillage forces for fatigue analysis of tillage machines
Authors: Abo Al-kheer, A.
Eid, M.
Aoues, Y.
El-Hami, A.
Kharmanda, M. G.
Mouazen, Abdul Mounem
Issue Date: 2011
Citation: A. Abo Al-kheer, M. Eid, Y. Aoues, A. El-Hami, M.G. Kharmanda, A.M. Mouazen, Theoretical analysis of the spatial variability in tillage forces for fatigue analysis of tillage machines, Journal of Terramechanics, Volume 48, Issue 4, August 2011, Pages 285-295.
Abstract: This paper presents a new theoretical model to describe the spatial variability in tillage forces for the purpose of fatigue analysis of tillage machines. The proposed model took into account both the variability in tillage system parameters (soil engineering properties, tool design parameters and operational conditions) and the cyclic effects of mechanical behavior of the soil during failure ahead of tillage tools on the spatial variability in tillage forces. The stress-based fatigue life approach was used to determine the life time of tillage machines, based on the fact that the applied stress on tillage machines is primarily within the elastic range of the material. Stress cycles with their mean values and amplitudes were determined by the rainflow algorithm. The damage friction caused by each cycle of stress was computed according to the Soderberg criterion and the total damage was calculated by the Miner's law. The proposed model was applied to determine the spatial variability in tillage forces on the shank of a chisel plough. The equivalent stress history resulted from these forces were calculated by means of a finite element model and the Von misses criterion. The histograms of mean stress and stress amplitude obtained by the rainflow algorithm showed significant dispersions. Although the equivalent stress is smaller than the yield stress of the material, the failure by fatigue will occur after a certain travel distance. The expected distance to failure was found to be df=0.825×106km. It is concluded that the spatial variability in tillage forces has significant effect on the life time of tillage machines and should be considered in the design analysis of tillage machines to predict the life time. Further investigations are required to correlate the results achieved by the proposed model with field tests and to validate the proposed assumptions to model the spatial variability in tillage forces
URI: http://dx.doi.org/10.1016/j.jterra.2011.05.002
http://dspace.lib.cranfield.ac.uk/handle/1826/6186
Appears in Collections:Staff publications - School of Applied Sciences

Files in This Item:

File Description SizeFormat
Theoretical_Analysis_of_the_Spatial_Variability_in_Tillage_Forces-2011.pdf1.02 MBAdobe PDFView/Open

SFX Query

Items in CERES are protected by copyright, with all rights reserved, unless otherwise indicated.