Papers by Author: Ju Ping Ren

Abstract: A 3D model of molecular dynamics for nanoceramic SiC is adopted to simulate the hot pressing sintering and preparation process of SiC, and mechanical properties such as density, hardness and elastic modulus are calculated. Finite element model of indentation is established based on the mechanical performance parameters from MD simulation. Conical indenter is adopted in indentation simulation. The FEM simulation results show that: Maximum equivalent stress appears at the place of indenter tip, and equivalent stress curves are appeared hemispherical. As indentation depth increases, the stress increased. As the distance of away from the indenter increases, the displacement in equivalent displacement nephogram gradually decreased until zero. During unloading process, elastic restitution is occurred. The elastic restitution in the area of below the indenter is obviously. Residual stress in the center of indentation is maximal after unloading.

Abstract: The microstructure evolution during sintering and preparation of nanoceramic materials is studied by molecular dynamics (MD) simulation. A 3D model for nanoceramic crystal body including mainly crystal planes of (100) and (110) is developed. This model is used to simulate the hot pressing of nanoceramic, especially for SiC, by rapid heating-up and cooling-down under certain pressure. In this model, the Tersoff potential function is used to simulate the interatomic force between atoms. The microstructure during melting process and crystallizing process are investigated by analyzing energy evolution, pair correlation function and the graph of instantaneous place of the atoms. The results show that the microstructure is amorphous after melting, and crystal planes of (100) and (110) are different in density, melting point and microstructure, showing anisotropy.

Abstract: With the increase of the quantity demanded, stone products with high quality, really artsy and diversification become more and more best-selling. The special-shaped stone machining equipments with numerical control, single machine intelligent, high speed, high efficiency and multi-function combination must be manufactured to produce these stone products. In this paper, 3D design and project optimization for special-shaped stone composite machining center are carried by Solid Works and innovative design. Model analysis of the crossbeam in this machining center is carried by ANSYS and the maximum deformation value in the crossbeam is found. The crossbeam structure is optimized by comparison and analysis. The design and manufacture of special-shaped stone combined machining center is very helpful for development of manufacturing.