Papers by Keyword: Micro Scale

Abstract: Cloud forming by solid explosive dispersal plays a decisive factor for twice-detonating FAE. The study of the flow field of internal cloud field can be more intuitive to understand the whole process of the formation of cloud diffusion, and it also has an important role to the delay time setting of secondary detonating fuze. Internal parameters of spreading cloud are difficult to obtain even through by the experiment method, but numerical analysis and simulations method can get the parameter. In this paper, we use experimental and simulation methods to study fuel dispersal process, aims to establish an effective and reliable mathematical models of cloud dispersal, and get the model data coinciding with the real situation.

Abstract: The sliding frictional contact problem for a laterally graded half-plane has been considered. Two finite element (FE) models, in macro and micro scales have been developed to investigate the effective parameters in contact mechanics of laterally graded materials loaded by flat and triangular rigid stamps. In macro scale model, the laterally graded half-plane is discretized by piecewise homogeneous layers for which the material properties are specified at the centroids by Mori-Tanaka method. In micro scale model, functionally graded material (FGM) structure has been modeled as ideal solid quadrant particles which are spatially distributed in a homogeneous matrix. Boundary conditions and loading is the same in both models. The microstructure has modeled as rearrangement and sizes changing of particles are possible to provide the possibility of crack nucleation investigation in non-singular regions. Analyses and comparison of the results showed that micro and macro scale results are in very good agreement. Also, increasing the grains aspect ratio and using optimum distribution of grains decrease stress distribution roughness on the surface. Therefore, the possibility of surface cracking far from stamp’s edges decreased.

Abstract: This paper provides an overview of advances in the surface metrology field, concerning surface creation, measurement need, instrumentation, characterisation methods and standard development. It indicates industry requirements and further developments for micro and nano scalar surface metrology.