Dynamic modelling and analysis for a flexible brush sampling mechanism

Sampling asteroid soil is one of the main tasks of asteroid exploration projects. The dynamic analysis for sampling with a flexible brush is of great interest in aerospace engineering. It is a typical dynamic problem of multi-body systems, including the flexibility of structure, granular material, the contact impact among the rigid bodies, flexible bodies, and granular matters, as well as the contact detection algorithm. To solve such a problem, this paper presents a strong coupling modelling method for the rigid bodies and the large deformed beams in interaction with the granular matter to simulate the sampling process. The absolute nodal coordinate (ANCF) Euler–Bernoulli beam element is adopted to discretize the flexible beams, while the motions of the rigid bodies and the particles are described by the Cartesian coordinates. A multi-level contact detection method is proposed to improve the simulation efficiency. The nonlinear continuous impact force model and velocity-based friction model are employed to describe the normal contact force and the tangential friction force, respectively. The coupling dynamic equations are solved simultaneously to achieve high precision. The dynamic model is verified via comparison with the commercial software on a benchmark problem. Finally, the dynamic performance of the flexible brush sampling mechanism is investigated, and the effects of structural parameters on sampling results are analysed.