Partner: Wojciech Sumelka

Politechnika Poznańska (PL)

Ostatnie publikacje
1.Sumelka W., Nowak M., On a general numerical scheme for the fractional plastic flow rule, MECHANICS OF MATERIALS, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2017.02.005, Vol.116, pp.120-129, 2018

Streszczenie:

This paper presents a general numerical scheme for the fractional plastic flow rule, dedicated to a wide class of materials manifesting the non-normality of plastic flow and induced plastic anisotropy. To determine the vector of the plastic flow, a special numerical procedure has been developed, which is applicable for any smooth and convex yield function. The obtained approximation is verified based on an analytical solution. The paper also presents a set of numerical results for the generalised Drucker–Prager model

Słowa kluczowe:

Non-normality, Plastic anisotropy, Fractional calculus, Return mapping algorithm

Afiliacje autorów:

Sumelka W.-Politechnika Poznańska (PL)
Nowak M.-IPPT PAN
40p.
2.Szymczyk M., Nowak M., Sumelka W., Numerical Study of Dynamic Properties of Fractional Viscoplasticity Model, SYMMETRY, ISSN: 2073-8994, DOI: 10.3390/sym10070282, Vol.10, No.282, pp.1-17, 2018

Streszczenie:

The fractional viscoplasticity (FV) concept combines the Perzyna type viscoplastic model and fractional calculus. This formulation includes: (i) rate-dependence; (ii) plastic anisotropy; (iii) non-normality; (iv) directional viscosity; (v) implicit/time non-locality; and (vi) explicit/stress-fractional non-locality. This paper presents a comprehensive analysis of the above mentioned FV properties, together with a detailed discussion on a general 3D numerical implementation for the explicit time integration scheme.

Słowa kluczowe:

fractional viscoplasticity, rate dependence, plastic anisotropy, non-normality, directional viscosity, explicit/implicit non-locality

Afiliacje autorów:

Szymczyk M.-Politechnika Poznańska (PL)
Nowak M.-IPPT PAN
Sumelka W.-Politechnika Poznańska (PL)
30p.
3.Sumelka W., Nowak M., Non-normality and induced plastic anisotropy under fractional plastic flow rule: a numerical study, INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, ISSN: 0363-9061, DOI: 10.1002/nag.2421, Vol.40, pp.651-675, 2016

Streszczenie:

In this paper, an implementation of fractional plastic flow rule in the framework of implicit and explicit procedures is under consideration. The fractional plastic flow rule is obtained from a generalisation of the classical plastic flow rule utilising fractional calculus. The key feature of this new concept is that in general, the non-associative flow is obtained without necessity of additional potential assumption. If needed, the model can cover the anisotropy induced by plastic deformation. Illustrative examples showing the unusual flexibility of this model are also presented.

Słowa kluczowe:

non-normality of plastic flow, fractional calculus, return mapping algorithm

Afiliacje autorów:

Sumelka W.-Politechnika Poznańska (PL)
Nowak M.-IPPT PAN
25p.
4.Glema A., Łodygowski T., Sumelka W., Perzyna P., Numerical Analysis of the Intrinsic Anisotropic Microdamage Evolution in Elasto-Viscoplastic Solids, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789508097543, Vol.18, No.3, pp.205-231, 2008

Streszczenie:

The objective of the present article is to show the formulation for elastic-viscoplastic material model accounting for intrinsic anisotropic microdamage. The strain-induced anisotropy is described by the evolution of the intrinsic microdamage process — defined by the second-order microdamage tensor. The first step of the possibility of identification procedure (calibration of parameters) are also accounted and illustrated by numerical examples.

Słowa kluczowe:

microdamage, anisotropy

Afiliacje autorów:

Glema A.-other affiliation
Łodygowski T.-other affiliation
Sumelka W.-Politechnika Poznańska (PL)
Perzyna P.-IPPT PAN