Abstract
Using the same experimentl method reported in the previous thesis, a series of factor tests were carried out.
The soil stress and the resistance force were analyzed.
The main results are the following:
(1) Elastic blade and spring-supported blade showed greater horizontal resistance than the rigid blade. This is caused by the greater compressive tendency of soil just in front of the blade.
(2) Decrease of blade length causes slight increase of horizontal resistance, which comes from the increase of cutting resistance and too much decrease of shearing action.
(3) Increase in width of the unit blade (totally, the same width) requires a little greater resistance.
(4) Because of the clogging of the furrow slice between the unit blades and increase of compression of the furrow slice, decrease in depth of unit blades causes much increase in resistance.
(5) As for the shape of the cutting edge, shorter edge line (especially the vertical part) causes smaller resistance.
(6) Smaller γ angle causes increase in resistance, which comes from greater cutting and frictional resistance.
