# Alfafa Stalk Crushing Simulation Test and Parameter Optimization Method
## 1 Introduction  
Stalk crushing is a crucial aspect of the forage industry as it directly impacts the quality of the subsequent feed. In recent years, there has been extensive research on the utilization of straw powder and grass powder, leading to the specialized production of stem crushing. Meeting the market demand for efficient stem crushing machinery has become increasingly pressing, prompting researchers to conduct comprehensive studies in this field [1, 2].  
A growing body of evidence suggests that a reasonable crushing structure plays an important role in the crushing quality of materials. [PERSON] et al. [3] developed a bionic blade to enhance the efficiency and quality of banana straw crushing. Through determining the optimal combination of parameters, they achieved a straw crushing qualification rate of 93.89%. [PERSON] et al. [1] conducted a corn bale crushing test using a fatigue testing machine. The results of the test demonstrated that the crushing process consists of two stages: compression and shearing. It was observed that the crushing force of the corn bale increases with an increase in both water content and blade angle. Furthermore, there was an interaction between the water content and the blade inclination angle. [PERSON] et al. [4] explored the crushing effect of corn ears under different rotational speeds of the cutter and different apertures of the sieve, and determined the optimal parameter combination when the efficiency is highest. To address the issue of the absence of precise discrete element models in the simulation analysis of corn straw crushing, [PERSON] et al. [5] developed bonding models with various structures, and corn straw particle models with different properties. They utilized Hertz-Mindlin combined with bonding technology to establish these models and calibrated the relevant parameters. The accuracy of the discrete element model wasvalidated through physical testing and simulation optimization design methods. In their research on the crushing problem, the scholars aimed to explore the relevant laws of the crushing process and determine more appropriate parameters. As the fields of crushing and types of materials continue to expand, extensive research will be conducted on crushing devices in the next few years. The aim is to enhance crushing quality and to minimize energy consumption through identifying the optimal structure and cutter for various material types and crushing needs.  
Most studies in the field of material crushing have only focused on the study of the difference in performance of a certain structure before and after optimization. However, there are few relevant studies on the horizontal comparison of multiple common crushing structures.  
To investigate the crushing effect of different structures of crushing devices on alfalfa, five different crushing tool structures were developed in this study, and the influence of different rotation speeds and different crushing results on the crushing effect was explored through the discrete element method. Through conducting range analysis, the study identified the primary and secondary influencing factors, as well as the optimal parameter combination. At the same time, a modal analysis was performed on the frame to ensure that resonances are avoided during operation. The findings of this study can serve as a valuable reference for the design of forage crushing devices.