Technology of magnetic abrasive finishing in machining of difficult-to-machine alloy complex surface

The technology of magnetic abrasive finishing is one of the important finishing technologies. Combining with low-frequency vibration and ultrasonic vibration, it can attain higher precision, quality and efficiency. The characteristics and the related current research of magnetic abrasive finishing, vibration assisted magnetic abrasive finishing and ultrasonic assisted magnetic abrasive finishing are introduced. According to the characteristics of the difficult-to-machine alloy's complex surface, the important problems for further study are presented to realize the finishing of complex surface with the technology of magnetic abrasive finishing, such as increasing the machining efficiency by enhancing the magnetic flux density of machining gap and compounding of magnetic energy and others, establishing of the control function during machining and the process planning method for magnetic abrasive finishing of complex surface under the space geometry restraint of complex surface on magnetic pole, etc

Integrating Mesh and Meshfree Methods for Physics-Based Fracture and Debris Cloud Simulation

We present a hybrid framework for physics-based simulation of fracture and debris clouds. Previous methods mainly consider bulk fractures. However, in many situations, small fractured pieces and debris are visually important. Our framework takes a hybrid approach that integrates both tetrahedron-based finite element and particlebased meshfree methods. The simulation starts with a tetrahedral mesh. When the damage of elements reaches a damage failure threshold, the associated nodes are converted into mass-based particles. Molecular dynamics is used to model particle motion and interaction with other particles and the remaining elements. In rendering, we propose an algorithm of dynamically extracting a polygonal boundary surface for the damaged elements and particles. Our framework is simple, accurate, and efficient. It avoids the remeshing and stability problems of pure mesh-based techniques and pure meshfree methods and offers high visual realism