Breaking Behaviour of Wheat Stem Undergoing Multiple Forces Combination Sequence during Threshing Process

During threshing process, wheat stems are easily broken when subjected to the combined forces of continuous tension, bending and compression of threshing bars. To reveal the causes of breakage, it is very significant to study the broken morphology and minimum breaking force of wheat stems undergoing multiple forces combination sequence. In this study, the mechanical characteristics of wheat stems undergoing single and combined forces were tested and analyzed. The results showed that when wheat stems are subjected to single load, the internodes are easiest to be broken under tensile force. When mixed-mode conditions of various forces are applied, the internodes are most easily broken under the combination of cantilever beam bending and three-point tension and the nodes of wheat are most prone to breakage when subjected to three-point compression. Under all loading states, the nodes of wheat are most prone to breakage when subjected to three-point compression. The damaged areas of internodes tend to be broken more easily. Consequently, the research of minimum breaking force of wheat stems undergoing multiple forces combination sequence reveals the substance of the breakage of wheat stems during threshing process.

Keywords:

Breaking force , Broken morphology , Combination way , Minimum force spectrum.