Abstract:
A catapult experimental device was designed to study the impact behavior and erosion mechanism of rhomboid particles impacting on metallic surfaces. Through the observation by high-speed camera, the motion trajectories of particles at different impact velocity
vi, impact angle
αi and orientation angle
θi were captured. A coupled numerical model (FEM-SPH) based on Lagrange method was established to deeply analyze the impact behavior of angular particle and deformation of crater profile. The results show that the initial orientation angle
θi, and the impact angle
αi, which were the major factors, determined the erosion mechanism. For agiven impact angle
αi, there existed a critical orientation angle
θcri; if
θi<
θcri, the particle tumbled forwards, while for initial orientation angles
θi>
θcri, the particle tumbled backwards after the impact. It also has been revealed that the rotation of particle highly influenced on the erosion mechanism. For example, a forwards rotating particle usually resulted in " ploughing” action, while " machining” action can be observed in a backward impact process. In addition, the impact angle
α and orientation angle
θ had a great influence on kinetic energy loss of particle. In general, impacts at critical initial orientation corresponded to the peak value of kinetic energy loss.