P. R. Ding
,
D. Y. Ju
,
T. Lnouc and E. de Vries( 1) MSC Japan Ltd.
,
Osaka
,
Japan 2) Saitama Institute of Technology
,
Saitama
,
Japan 3) Kyoto Universily
,
Kyoto
,
Japan 4) MacNeal - Schwendler (E. D. C. ) B. V.
,
Gouda
,
The Netherlands)
金属学报(英文版)
A method to simulate processes of forging and subsequent heat treatment of an axial symmetric rod is formulated in eulerian description and the feasibility is investigated. This method uses finite volume mushes for troching material deformation and an automatically refined facet surface to accurately trace the free surface of the deforming material.In the method,the deforming work piece flows through fixed finite volume meshes using eulerian formulation to describe the conservation laws,Fixed finite volume meshing is particularly suitable for large three-dimensional deformation such as forging because remeshing techniques are not required, which are commonly considered to be the main bottelencek in the ssimulations of large defromation by using the finite element method,By means of this finite volume method, an approach has been developed in the framework of "metallo-thermo-mechanics" to simulate metallic structure, temperature and stress/strain coupled in the heat treatment process.In a first step of simulation, the heat treatment solver is limited in small deformation hypothesis,and un- coupled with forging. The material is considered as elastic-plastic and takes into account of strain, strain rate and temperature effects on the yield stress.Heat generation due to deformation,heat con- duction and thermal stress are considered.Temperature - dependent phase transformation,stress-in- duced phase transformation,latent heat,transformation stress and strain are included.These ap- proaches are implemented into the commerical commercial computer program MSC/SuperForge and a verification example with experimental date is given as comparison.
关键词:
finite volume method
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N. Tada
,
T. Kitamura
,
R. Ohtani and E. Nakayama (Department of Engineering Physics and Mechanics
,
Graduate School of Engineering
,
Kyoto University
,
Yoshida-hommachi
,
Sakyo-ku
,
Kyoto
,
606-8501
,
Japan)
金属学报(英文版)
Creep-fatigue test was carried out using smooth round bar specimens of Type 304 stainless steel. Cavities and small cracks on the cross-section of the specimen were carefully observed by a scanning laser microscope. Moreover, direct current electrical potential method (DC-EPM) was applied in order to evaluate non-destructively the distribution of internal cracks. The distribution evaluated by DC-EPM agreed well with the actual one.
关键词:
creep-fatigue
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null
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