## 1 Introduction  
China's sugarcane-planted area in 2020 is 1353.38 thousand hectares, accounting for more than 85% of the sugar-planted area [1]. However, the degree of mechanized harvesting of sugarcane in China is very low, with the level of mechanization of sugarcane harvesting in China being around 3.2% in the 2019/2020 crushing season [2]. After the harvest of sugarcane, a large number of sugarcane leaves fall off, and the germination of sugarcane root and field management are seriously affected. Therefore, it is necessary to treat the sugarcane leaves left in sugarcane fields. In countries where the sugar cane industry is more developed, such as Brazil, India and Australia, large cutber combine harvesters with collection trucks are used to harvest the came and shred the leaves, or tractors with disc harrows are used to crush the leaves [3]. Domestic scholars have conducted a lot of research on the technology of returning cane leaves to the field, and have developed a series of sugar cane leaf crushing and returning machines [4; 5; 6]. However, these return machines have problems with their own weight and energy consumption, which can cause serious soil compaction and damage to the perennial roots. Therefore, South China Agricultural University has developed a light electric sugarcane leaf cutting and returning machine [7; 8] which can be remotely controlled and does not damage perennial roots. At present, the third generation electric sugarcane leaf cutting machine has been developed. However, the picking contact mechanism of electric sugarcane leaf cutting and returning machine is still unclear, and there are large gaps in the research on the interaction between the sugarcane leaf and the picking mechanism. Therefore, it is necessary to analyze the picking process of sugarcane leaves in detail. The contact between the picking mechanism and the sugarcane leaf faces the problem of large deformation of the flexible bodies. The common methods for analyzing the interaction between two flexible bodies are the finite element method and the discrete element method. The discrete element method has many problems; there are too many input parameters, the parameters need to be calibrated, and the calculation is huge. In contrast, the finite element method has a small calculation scale and is easy to accomplish. ANSYS/LS-DYNA software is commonly used to analyze non-linear dynamics problems and can describe the stress distribution of flexible bodies under large deformation conditions more accurately, and the simulation can save a lot of cost and time in field experiments. [PERSON] et al. [9] modelled the maize stalk in ANSYS and investigated the process of the harvesting mechanism on the stalk. [PERSON] et al. [8] carried out a simulation of the working process of a tracked flexible knife cutting and returning machine with the aid of LS-DYNA, and simulated the cutting of cane leaves by a high-speed rotating nylon flexible knife. [PERSON] et al. [10] used LS-DYNA to establish a finite element model of river ice collision on a pier. The finite element model for calculating the collision force between river ice and a flexible pier was also studied. [PERSON] et al. [11] investigated the high-speed impact energy absorption properties of pure and STF-impregnated Kevlar fabrics using LS-DYNA. [PERSON] et al. [12] used a finite element method to simulate the dynamic characteristics of large deformations during the unfolding of a flexible spinning web. [PERSON] et al. [13] constructed a finite element model of the sugarcane defoliation process using hypermesh and LS-DYNA software. [PERSON] et al. [14] used the explicit analysis method of ANSYS software to simulate the ballistic performance of SiC-UHMWPE flexible laminated structures. [PERSON] et al. [15] conducted a dynamic cutting mechanics simulation based on LS-DYNA for a double-layer flexible model of cereal stalks, and carried out validation experiments using a home-made cutting experiment rig. [PERSON] et al.