## 1 Introduction
[25] studied the surface morphology of soil animals, designed a stripe-like non-smooth surface, and carried out friction and wear tests. The results showed that the wear resistance of several non-smooth surfaces was better than that of smooth surfaces. [PERSON] et al. [26] studied the abrasive wear behavior of the subsoiler shovel blade with a bionic rib geometry structure. The experimental results showed that the bionic geometry structure could change the motion state of the abrasive material and effectively reduce the wear severity of the surfaces. The research mentioned above successfully adopted bionic engineering technology, that by learning the surface morphology of soil animals and applying them to optimize the surface of a bionic geometrical structure, effectively enhances the wear resistance performance of agricultural machinery. In the investigations of abrasive wear behavior, the discrete element method is an important numerical simulation approach to solve the discrete problem of materials [25]. The wear of the sample surface is caused by the continuous impact and friction of a large number of particles. The numerical simulation of abrasive wear with the discrete element method could be comprehensively used to investigate the movement of particles, reveal the wear mechanism of different geometrical structured surfaces, obtain the microscopic wear behavior of the worn surface, quantitatively calculate the abrasion loss, display the geometric characteristics of the worn surface, and predict the wear area of the sample surface [27]. For example, [PERSON] [28] used the discrete element method to simulate the soil abrasive wear behavior of the bionic geometric structure surface and analyzed its wear mechanism. It was proved that the rebound angle after the contact between the abrasive material flow and the wear surface had a great influence on the worn surface. [PERSON] et al. [29] developed the discrete element model of the semi-autogenous mill, then studied the main factors that affected the grinding performance of the semi-autogenous mill by EDEM numerical simulation. [PERSON] et al. [30] and [PERSON] et al. [31] used the discrete element method to analyze the wear characteristics of ball mill liner, and effectively predicted the main wear area. In the bionic design on the geometrical structure by learning from wear-resistant organisms carried out by [32; 33; 34], the abrasive wear performance of the bionic non-smooth geometric structure surface was studied by the discrete element method, and the wear resistance mechanism was analyzed. It was found that the wear resistance of the bionic non-smooth geometric structure surface was better than that of an ordinary smooth surface. _Procambarus clarkii_ is also known as red crayfish or freshwater crayfish. In order to adapt to its surrounding living environment, this species of soil animal needs to continuously excavate caves in the abrasive soil for most of its lifetime. The time duration of a single burrowing activity of _Procambarus clarkii_ could last as long as 8 h, and the single excavation depth could reach 40 cm. The external surface of the exoskeleton of its Cephalothorax could still remain intact after such long time of contact with the soil particles. Many studies have shown that the external surface of _Procambarus clarkii_ has excellent wear resistance performance [35; 36; 37]. In this study, bionics engineering was used as the technical approach, and the surface morphology of the cephalothorax exoskeleton of _Procambarus clarkii_ was adopted as the bionic prototype. The geometrical structure characteristics were analyzed and extracted, and the bionic non-smooth geometrical structure surface model was established. The abrasive wear test and EDEM simulation investigations were carried out to explore the abrasive wear performance and wear resistance mechanism under the impact action of abrasive particles, which provides a theoretical basis for the bionic design of agricultural machinery with improved wear resistance performance.