Engineering Transactions, 53, 4, pp. 397–414, 2005
10.24423/engtrans.451.2005

Analyses of Plane Stress Discontinuity Lines Systems in Oyane Porous Media

W. Bodaszewski
Kielce University of Technology
Poland

The paper presents the results of numerical analyses of certain properties of plane stress discontinuity lines systems, which are specific for the Oyane condition, and do not appear when one assumes other yield conditions, such as Huber-Mises or Tresca conditions. The results have been obtained by applying general algorithms that do not require for-emulating any individual relationships. The algorithms aid solving problems for any boundary conditions, of practically any type, which can be met in the problems of construction of dis-continuous statically admissible fields, mainly the limit fields. In the assumed formulation, the solution consists in finding initially the fields arising around isolated nodes of stress discontinuity lines, and then integrating the fields into two-dimensional complex fields. Application of these algorithms makes it possible to quickly find all the existing solutions of the stress discontinuity lines around the nodes, at the same time eliminating the need of forecasting (guessing the solution), which until recently was the main difficulty in solving each new complex field. Physical justification of the Oyane condition is beyond the scope of this work.
Keywords: shape design; limit analysis; numerical methods
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Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).

References

W. SZCZEPIŃSKI Plastic design of machine parts [in Polish] PWN, Warszawa, 1968.

M. OYANE, S. SHIMA, Y. KONO, Theory of plasticity for porous metals, Bull. JSME, 16, 1254–1262, 1973.

I. MARKIEWICZ, Numerical determination of statically admissible link systems of stress discontinuity lines in limit the Huber-Mises's fields [in Polish], PhD thesis, Warsaw University of Technology, 1996.

J. MIELNICZUK, Plasticity of porous materials. Theory and the limit load capacity, Poznań University of Technology, 2000.

J. MIELNICZUK, R. MOSTOWSKI, Designing porous structural elements by the use of the limit analysis method [in Polish], WSP Zielona Góra 2000.

W. SZCZEPIŃSKI, J. SZLAGOWSKI, Plastic design of complex shape structures, Ellis Horwood & PWN, Warszawa – Chichester 1990.

W. BODASZEWSKI, A. BUCZYŃSKI, Domain existence limit stress discontinuity system in Oyane porous media, 34th Solid Mechanics Conference, SolMech 2002.

W. BODASZEWSKI, Stress discontinuity line structures in yield zones satisfying the Huber–Misses condition [in Polish], Engng. Trans., part 1 36, 1, 29–54, 1988; part 2 37, 3, 415–442, 1989.

W. BODASZEWSKI, Algorithms of the method of statically admissible discontinuous stress fields (SADSF), Engng. Trans., (Part I – 3/2004, remaining 3 parts – in print).

W. BODASZEWSKI, The software package KNPN for approximated shaping of complex plastic structures, VIII Symposium on Stability of Structures, Łódź University of Technology, 25–30, 1997.

Internet website www.sadsf.net




DOI: 10.24423/engtrans.451.2005