Design and optimization of an astragalus slicing machine using computer simulations and design of experiments

Abstract

To address the problems of fragmentation, uneven thickness, and high loss rates when slicing root and stem Chinese medicinal materials with low moisture and high fiber content, a novel disk-type Astragalus slicing machine was designed. Cutting mechanics and motion parameters were analyzed and optimized using the Discrete Element Method (DEM). Mechanical properties of three-year-old Astragalus roots from Min County, Gansu Province were determined through tensile, compression, and shear tests, and a DEM model of the root system was established. Cutting edge angle, cutter disk speed, and feed rate were selected as key parameters, with maximum cutting force and bond breakage as evaluation indicators. A response surface methodology was applied to optimize these factors. Simulation results indicated optimal performance at a blade angle of 25°, disk speed of 550 r/min, and feed rate of 144 mm/s, yielding a predicted maximum cutting force of 22.3 N. Prototype testing confirmed these findings (22.7 ± 1.1 N, <8 % deviation), achieving a compliance rate of 97.4 %, slice smoothness of 96.2 %, and a loss rate of only 3.5 %. The optimized design effectively balances frictional and centrifugal forces while reducing contact time, improving both slicing quality and efficiency. This study introduces, for the first time, DEM-based mechanical calibration and response surface optimization in the design of slicing equipment for Chinese medicinal roots. The results provide a technical route from modeling to prototype verification and offer a theoretical basis for developing efficient, high-quality slicing equipment for fibrous medicinal materials.