Experimental Research on the Bending and Fracture Characteristics of Cotton Stalk

HighlightsA two-factor randomized block design was used to study the influence of experimental factors on indicators.Specific fracture energy can indicate the relationship between mass and power.A cotton stalk model was established using the discrete element method (DEM).Abstract. Effectively chopping of the mixture of mulch film and cotton stalk recycled by machine is the only way to achieve subsequent separation of the materials. Cotton stalk is one of the main components of the mixture. According to the working principle of a chopping device, the bending and fracture characteristics of cotton stalk samples were measured. A two-factor random block design was used to study the effects of moisture content and sample location on the plant on the mechanical characteristics of the stalk samples. According to the results, the specific fracture energy of the stalk samples was calculated. The results showed that the relationship between the moisture content and bending performance of the samples was an inverse proportional function in general. However, when the moisture content was 20% to 30%, the fracture energy in the double-support bending tests was low, which was therefore the most suitable condition for chopping. In addition, a cotton stalk model was established using the discrete element method (DEM), and the optimal parameter combination was determined. Compared with the actual test results, the model error of the peak bending force was 1.20%. This study can support the analysis of chopping device simulation and material preparation in experimental research. Keywords: Bending fracture characteristics, Cotton stalk, Discrete element method, Three-point bending test.