A. Dragon


Doktorat
1976Mechanika ośrodków kruchoplastycznych z wewnętrznymi parametrami zniszczenia 
promotor -- prof. dr hab. inż. Zenon Mróz, IPPT PAN
272 
Ostatnie publikacje
1.Dragon A., Fenomenologiczne kryterium lokalnego zapoczątkowania makropękania w ośrodku plastyczno - kruchym (skałopodobnym), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.17, pp.1-38, 1980
2.Dragon A., Mróz Z., A continuum model for plastic-brittle behaviour of rock and concrete, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/0020-7225(79)90058-2, Vol.17, No.2, pp.121-137, 1979

Streszczenie:

The present work deals with a continuum model for time-independent behaviour of progressively fracturing solids. The rate theory with fracture parameter is discussed and applied to rock-like materials. In particular, elastic-brittle and plastic-brittle idealizations are considered with the fracturing affecting elastic and plastic strains, respectively. The elastic-brittle model incorporates, however, the plasticity-like concept of varying fracture surface. Also the idea of a limit (failure) locus is introduced as the stress-path dependent condition, instead of being prescribed a priori. The plasticity model attempts to cover both stable and unstable portions of the stress-strain relation while the fracture parameter is coupled with irreversible volumetric dilatancy. The general model is applicable to wider class of engineering materials, ƒ. ex. to metals in advanced yielding accompanied with microfracturing.

Afiliacje autorów:

Dragon A.-other affiliation
Mróz Z.-IPPT PAN
3.Dragon A., Mróz Z., A model for plastic creep of rock-like materials accounting for the kinetics of fracture, International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, ISSN: 1365-1609, DOI: 10.1016/0148-9062(79)91200-2, Vol.16, No.4, pp.253-259, 1979

Streszczenie:

The constant stress creep behaviour of rocks is studied. A model is presented employing assumption that time-dependent microcracking is responsible for the macroscopic viscoplastic deformation. Irreversible volumetric creep is included as the main concern is the material behaviour for stress-levels over the ‘discontinuity’ locus which is identified with the initial yield point. A modified formalism of plasticity theory is used with a scalar crack-density parameter. The steady-state and tertiary creep stages (up to failure) are described by the simplified theory. identification of material parameters is discussed and an example of creep curves for the case of homogeneous biaxial compression is given to illustrate applicability of the model.

Afiliacje autorów:

Dragon A.-other affiliation
Mróz Z.-IPPT PAN
4.Dragon A., Mróz Z., On the plastic-brittle behaviour of rock and concrete, Mechanics Research Communications, ISSN: 0093-6413, DOI: 10.1016/0093-6413(76)90106-3, Vol.3, No.5, pp.429-434, 1976
5.Dragon A., Mechanika ośrodków krucho-plastycznych z wewnętrznymi parametrami zniszczenia (Praca doktorska), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.12, pp.1-146, 1976
6.Dragon A., Metody wyznaczania naprężeń i odkształceń w górotworze, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.44, pp.1-22, 1975
7.Dragon A., Kontynualny model ośrodka z parametrem przebudowy struktury (zastosowanie do opisu skał i betonów), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.64, pp.1-53, 1974