Experimentation and Analysis of Physical Properties Related to Quinoa Straws

To study the cutting mechanical properties of quinoa straw and reduce the cutting force and unit area cutting power consumption of quinoa straw, this study took quinoa from low-altitude areas as the research object. Through observation and experimental analysis of quinoa from low-altitude areas, the relevant external characteristics of quinoa straw were recognized, providing a certain research basis for the development of quinoa-specific harvesting machinery. In the cutting mechanical experiments, a reciprocating cutting test bench for straw was designed. Single-factor experiments were conducted on the moisture content, cutting speed, blade angle, and cutting angle of quinoa straw. Response surface experiments were conducted on cutting speed, blade inclination angle, and cutting inclination angle to reveal the variation laws of the cutting mechanical properties of quinoa straw, providing a scientific basis for the rational formulation of harvesting strategies. In the single-factor experiments, the ultimate cutting stress of the stem and the unit area cutting power consumption decreased with the increase in moisture content; the ultimate cutting stress of the stem and the unit area cutting power consumption decreased first and then increased with the increase in cutting inclination angle; the ultimate cutting stress of the stem decreased with the increase in blade inclination angle, while the unit area cutting power consumption decreased first and then increased; the ultimate cutting stress of the stem and the unit area cutting power consumption decreased first and then remained stable with the increase in average cutting speed. In the response surface experiments, the optimal parameter combination was an average cutting speed of 0.8 m/s, a cutting inclination angle of 9.8°, and a blade inclination angle of 33.2°. The verification test proved that the error was no more than 4%. Under the optimal parameters, the ultimate cutting stress and unit area cutting power consumption of the straw were 9.1% and 2.9%, respectively.