Researchs Based On IGES Three-dimensional Model And MCNP Interface

MCNP is a general-purpose Monte Carlo N-particle that can be used for neutron,photon, electron,or coupled neutron/photon/electron transport. It's used widely,but it is very complicated to construct its simulation model. The process of inputting INP file is very fussy in building geometry model of MCNP.The paper mainly researched,based on IGES semantic model, how to obtain data information of graphic model from IGES data file as data resource and processed these data to obtain character parameters needed by graph.Realizing automatic building of model for engineering emulation computing and automatic converting it into input file of MCNP.So it greatly improved the efficiency of the building of geometry model in Monte Carlo computing program.The main contain is as followed:(1)The general develoment process of CAD/CAM is reviesed.The purpose and significance of this article are discussed.(2)According to the development and the main content of the IGES standard,the author detailedly studies the structure,from,topological relation of the graphics,definition of geometry information element of the IGES data file.And an example of IGES data file is giving in SolidWorks environment.(3)The geometry sculpting including two dimension and three dimension model is studied.The major purpose of the research is that how to definite and memorize the integrated information and how convenient to construct the model.(4) From building of instance model to creation of corresponding IGES data files,obtaining parameter data through topology relations and geometry description.With VC++,converting it into INP file recognizable for MCNP,adding contents of density,importance and so on in INP file,making calculation of MCNP file directly. (5)Conclusion and reseraching directions of the future are simmarized. By analyzing the theoretics and the example,the study of the parameter in this paper is feasible.