Skip to main content
Article thumbnail
Location of Repository

An investigation into the mechanics of agricultural discs

By Abdullah Ali Al-Ghazal

Abstract

A prediction model based upon Mohr-Coulomb soil mechanics theory has been developed to predict the interaction between the soil and agricultural discs of different geometries and operating angles to both vertical and tilted discs. The model is based on two forms of soil failure. The magnitude of each form of failure is depen- dent upon a passive reaction on the concave side of the disc and a vertical bearing reaction on the convex side of the disc. The predicted results are in close agreement with the results of the experimental studies. Disc geometry is one of the most important factors to be considered in evaluating the soil reaction acting upon a disc tool. A theoretical analysis of the disc geometry was therefore carried out. The analysis of the disc geometry makes it possible to determine the factors required for the predicted forces acting on a disc tool. The experimental studies were conducted in a sandy loam soil at a moisture content in the friable range, under controlled soil bin conditions. The work was carried out at full-scale with 3 dimensional force measuring apparatus developed primarily for this investigation. The discs studied had a range of disc angles between 150 and 600 and a range of tilt angles between 0 and 35. The depth of cut ranged from 80 mm to 140 mm and at speeds between 0.75 m/s and 1.5 m/s. The disturbance area of the soil caused by the rotating soil cutting disc is calculated to define the disturbed area for any combination of disc angle, disc diameter, gang spacing and depth of work in order to accurately calculate specific resistance. Disturbance and soil inversion were investigated using transparent discs and soil tracers, with a variety disc and tilt angles in order to quantify inversion and mixing

Publisher: Cranfield University
Year: 1989
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/5043
Provided by: Cranfield CERES

Suggested articles

Citations

  1. (1967). A model of vibratory soil cutting. Society of Automotive Engineers. Paper no. 670750, presented at the Farm construction and Industrial Machinery Meeting,
  2. (1986). An analysis of the geometric and soil working parameters of a curved vertical disc. doi
  3. (1975). An extended octagonal ring transducer for use in tillage studies. doi
  4. Design of soil engaging implements. doi
  5. (1930). Dynamic properties of soil affecting implement design.
  6. (1960). Further work on the relationship between rake angle and the performance of simple cultivation implements.
  7. (1939). Improvement of cisc tools.
  8. (1936). Measurement of forces on soil tillage tools.
  9. (1965). Mechanics of soil as influenced by model tillage tools.
  10. (1982). National Institute of Agricultural Engineering, Silsoe, doi
  11. (1954). Pitfalls in applying the science of mechanics to tractor and implements.
  12. Principles and procedures of statistics. doi
  13. (1961). Report 12,8th Meeting of the Wind Tunnel and Model Testing Panel, 20th - 25th February. Rome Meyerhof,
  14. (1963). Soil force analysis as applied to tillage equipment.
  15. (1969). Soil mechanics.
  16. (1944). Technical features of tillage tools.
  17. (1931). The dynamics of soil I. An explanation of the dynamic properties of soils by means of colloidal films.
  18. (1956). The geometry of discs and soil relationships.
  19. (1980). The influence of velocity and disc angle on the kinematic parameter of discs. doi
  20. (1976). The irregularity of soil disturbance depth by circular and rotating tillage tools. doi
  21. (1932). The physical properties of soil, of interest to agricultural engineering.
  22. (1970). Three-dimensional interference between two tillage tools. Unpublished Ph.
  23. (1963). Wheatland disc plough investigations. II. Disc forces.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.