1. | Olszak W., Ostrowska-Maciejewska J., The plastic potential in the theory of anisotropic elastic-plastic solids, ENGINEERING FRACTURE MECHANICS, ISSN: 0013-7944, DOI: 10.1016/0013-7944(85)90072-4, Vol.21, No.4, pp.625-632, 1985Abstract:In the paper the yield condition is proposed for the most general anisotropic material. It is one of the possible generalizations of the Huber-Mises-Hencky yield condition for the case of anisotropy. The body considered is anisotropic elastically as well as plastically. It is assumed that the plastic anisotropy tensor is a definite function of the elastic anisotropy tensor. The corresponding flow function is a part of the strain energy and its value remains unchanged when all normal components of stress are increased by the same value. The theory of the eigen states for fourth order tensors is used. The plastic anisotropy tensor proposed has the same deviatoric eigen states as the elastic anisotropy tensor. The proposed yield condition reduces to that of Huber-Mises-Hencky when the anisotropy is vanishingly small. The method presented in this paper can be also applied to describe other types of plastic anisotropy tensor. Affiliations:Olszak W. | - | IPPT PAN | Ostrowska-Maciejewska J. | - | IPPT PAN |
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2. | Nowacki W., Olszak W., Misztal F.♦, Szymanowski W.♦, Nałęcz M.♦, Wydział IV - Nauk Technicznych w 25-leciu Polskiej Akademii Nauk, Nauka Polska, ISSN: 0028-1271, Vol.XXVI, No.5, pp.23-29, 1978 | |
3. | Bychawski Z., Olszak W., Rheological approach to crack propagation and fracture mechanisms, ENGINEERING FRACTURE MECHANICS, ISSN: 0013-7944, DOI: 10.1016/0013-7944(76)90092-8, No.8, pp.1-267, 1976Abstract:The paper is concerned with a nonlinear description of the kinetics of crack propagation in bodies exhibiting rheological properties. The analysis is based on the concept of a time-dependent cohesion modulus for an ageing nonlinear viscoelastic material. A simple model of an infinite thin plate with a rectilinear crack is considered. The discussion is followed by some conclusions. Affiliations:Bychawski Z. | - | IPPT PAN | Olszak W. | - | IPPT PAN |
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4. | Olszak W., Perzyna P., Physical theory of viscoplasticity for small deformations, Mechanics Research Communications, ISSN: 0093-6413, DOI: 10.1016/0093-6413(74)90062-7, Vol.1, No.4, pp.187-190, 1974 | |
5. | Olszak W., Plastizitäts-und energetische Kennzeichnungskriterien für rheologisch reagierende Stoffe, ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, ISSN: 0044-2267, DOI: 10.1002/zamm.19730531227, Vol.53, No.12, pp.T77-T77, 1973 | |
6. | Olszak W., Perzyna P., On thermal effects in viscoplasticity, ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK ZAMP, ISSN: 0044-2275, DOI: 10.1007/BF01590623, Vol.20, No.5, pp.676-680, 1969 | |
7. | Olszak W., Perzyna P., Les equations constitutives et phenomenes de relaxation dans les milieux elasto/visco-plastiques, Rendiconti del Seminario Matematico e Fisico di Milano, ISSN: 0370-7377, DOI: 10.1007/BF02924479, Vol.38, No.1, pp.12-18, 1968Abstract:The paper consists of two parts. The first part is devoted to a discussion of the constitutive equations describing the dynamic properties of soils. In the second part, the relaxation problem in an elastic/visco-plastic soil is considered. Affiliations:Olszak W. | - | IPPT PAN | Perzyna P. | - | IPPT PAN |
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8. | Olszak W., Sur la théorie des phénomènes visco-plastiques, Rendiconti del Seminario Matematico e Fisico di Milano, ISSN: 0370-7377, DOI: 10.1007/BF02924478, Vol.38, pp.9-11, 1968Abstract:The lecture presents a synthetic survey on the theory of viscoplasticity (reflecting the rate-sensitive dynamic properties of materials). Some examples of its applications are also discussed (relaxation phenomena occurring in elastic/visco-plastic media as well as the propagation of stress waves in such continua). Besides, we generalize the existing theories by introducing a nonstationary yield condition (variable with time). Finally we propose a further generalization of the yield criterion based on the notion of the conserved (accumulated) as well as the dissipated energy. Affiliations: | |
9. | Olszak W., Perzyna P., The constitutive equations for elastic/visco-plastic soils, Journal of Mathematical and Physical Sciences, ISSN: 0047-2557, Vol.2, pp.67-72, 1968 | |
10. | Bychawski Z., Olszak W., Energetyczna interpretacja stanów krytycznych w ciałach lepkosprężystych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.2, pp.1-53, 1967 | |
11. | Olszak W., Rychlewski J., Urbanowski W., Plasticity Under Non-Homogeneous Conditions, Advances in Applied Mechanics, ISSN: 0065-2156, DOI: 10.1016/S0065-2156(08)70122-4, Vol.7, pp.131-214, 1962Abstract:The theory of plasticity represents one of the branches of rapidly developing continuum mechanics. The progress consists of both a careful analysis of the basic equations and physical relations and an extension of the range of problems and effective solutions covered by this theory. In real media the non-homogeneity of mechanical properties may be caused by numerous phenomena and its nature may be very diverse. First, it is evident that a universal property of bodies occurring in practice is their microscopic non-homogeneity. It is well- known that there have been many successful1 attempts to include microscopic non-homogeneity in the structure of Continuum Theory. The objective of the chapter, however, is the macroscopic nonhomogeneity that is taking place in regions whose linear dimensions are comparable with the characteristic dimensions of the body under consideration. The nonhomogeneity of mechanical properties may be caused, for instance, by phenomena such as the influence of flow of elementary particles, the action of temperature gradients, a nonhomogeneous hardening of the material, different types of surface working, nonhomogeneity of the composition, and so on. Affiliations:Olszak W. | - | IPPT PAN | Rychlewski J. | - | IPPT PAN | Urbanowski W. | - | IPPT PAN |
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12. | Perzyna P., Olszak W., Propagation of spherical waves in a non-homogeneous elastic-viscoplastic medium, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, Vol.9, pp.509-516, 1961 | |
13. | Olszak W., On some basic aspects of the theory of non-homogeneous loose and cohesive media, ARCHIWUM MECHANIKI STOSOWANEJ, ISSN: 0373-2029, No.6, pp.751, 1960 | |
14. | Olszak W., Perzyna P., Variational theorems in general viscoelasticity, Ingenieur-Archiv, ISSN: 0020-1154, DOI: 10.1007/BF00536117, Vol.28, No.1, pp.246-250, 1959 | |
15. | Olszak W., Mróz Z., Note on the completeness of elastic-plastic solution to certain boundary-value problems for the eccentric ring, ARCHIWUM MECHANIKI STOSOWANEJ, ISSN: 0373-2029, Vol.10, pp.441-444, 1958 | |
16. | Olszak W., Murzewski J.♦, Elasto-plastische Biegung von nicht-homogenen orthotropen Kreisplatten, ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, ISSN: 0044-2267, DOI: 10.1002/zamm.19570370728, Vol.37, No.7-8, pp.277-278, 1957 | |
17. | Olszak W., Mróz Z., Elastic bending of circular plates with eccentric holes /application of the method of inversion/, ARCHIWUM MECHANIKI STOSOWANEJ, ISSN: 0373-2029, Vol.9, No.125, pp.153, 1957 | |
18. | Olszak W., Urbanowski W., The plastic potential and the generalized distorsion energy in the theory of non-homogeneous anisotropic elastic-plastic bodies, ARCHIWUM MECHANIKI STOSOWANEJ, ISSN: 0373-2029, Vol.8, No.4, pp.671-694, 1956 | |
19. | Mutermilch J.♦, Nowacki W., Olszak W., Dziesięciolecie rozwoju konstrukcji inżynierskich w Polsce Ludowej, INŻYNIERIA I BUDOWNICTWO, ISSN: 0021-0315, Vol.11, No.7, pp.198-201, 1954 | |