Papers by Author: Ke Zhang

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: Theoretical analysis of existing evaluation method of gap roundness error and existing evaluation model of full roundness error is provided. Mathematical model of gap roundness error’s evaluation with least square method is founded based on the evaluation model of full roundness error, which gives a solution of gap roundness error. The results of the simulation analysis and measuring experiment show that mathematical model of gap roundness error’s evaluation with least square method is correct for computing gap roundness error.