dr hab. inż. Andrzej Drescher


Doktorat
1968Badanie własności reologicznych gruntów spoistych 
promotor -- prof. dr hab. inż. Zenon Mróz, IPPT PAN
139 
Habilitacja
1976Badanie mechanizmów plastycznego płynięcia materiałów ziarnistych 
Promotor prac doktorskich
1.1980Skłodowski Marek  Zmodyfikowana metoda holograficznego pomiaru sumy naprężeń głównych w modelach elastooptycznych 

Ostatnie publikacje
1.Boukpeti N., Mróz Z., Drescher A., Modeling rate effects in undrained loading of sands, Canadian Geotechnical Journal, ISSN: 0008-3674, DOI: 10.1139/t03-077, Vol.41, No.2, pp.342-350, 2004

Streszczenie:

The present technical note extends the previous work by the authors concerned with formulation of a constitutive model of elastoplastic response of sands (Superior sand model) and its application to the analyses of static liquefaction and instability states in triaxial compression and extension occurring in the undrained deformation of saturated granular materials. To account for time-dependent behavior and strain rate effects, an elastic, viscoplastic extension of the model to triaxial compression is proposed. The constitutive equations derived are used to predict the model response in different loading histories. In particular, strain rate and stress rate effects and undrained creep deformation for specified stress components are discussed in detail. Comparison of model predictions with available experimental data also is provided.Key words: saturated sand, constitutive model, elastic–viscoplastic behavior.

Afiliacje autorów:

Boukpeti N.-University of Western Australia (AU)
Mróz Z.-IPPT PAN
Drescher A.-other affiliation
2.Mróz Z., Boukpeti N., Drescher A., Constitutive model for static liquefaction, International Journal of Geomechanics, ISSN: 1532-3641, DOI: 10.1061/(ASCE)1532-3641(2003)3:2(133)#sthash.LLxWvMhd.dpuf, Vol.3, No.2, pp.133-144, 2003

Streszczenie:

A general, three-dimensional formulation of the elastoplastic refined Superior sand constitutive model is presented. The model is aimed at realistic simulation of liquefaction phenomena occurring in loose saturated granular materials under monotonic static loading. The isotropic hardening/softening is related to plastic deformation and distance to a reference yield surface. The nonassociated flow rule is used with the closed yield surface introduced previously in the Superior sand model. The refined model accounts for the different response of materials with different deposition densities. The model prediction of drained and undrained plane-strain compression is presented and compared with the response in triaxial compression/extension loading. Static and kinematic instability states also are discussed.

Afiliacje autorów:

Mróz Z.-IPPT PAN
Boukpeti N.-University of Western Australia (AU)
Drescher A.-other affiliation
3.Boukpeti N., Mróz Z., Drescher A., A model for static liquefaction in triaxial compression and extension, Canadian Geotechnical Journal, ISSN: 0008-3674, DOI: 10.1139/t02-066, Vol.39, No.6, pp.1243-1253, 2002

Streszczenie:

The response of the elastoplastic refined Superior sand constitutive model in undrained triaxial compression and extension tests is presented. The model is aimed at realistic simulation of liquefaction occurring in loose, saturated, granular materials under monotonic static loading. The yield surface introduced previously in the original Superior sand model is modified, and a non-associated flow rule is used. The isotropic hardening–softening is related to plastic deformation and distance to a reference yield curve. The refined model accounts for the different response of materials with different deposition densities. The model prediction of undrained triaxial compression and extension tests is compared with experimental results. The higher tendency for liquefaction response in extension is well described. Instability and phase-transformation states also are discussed, and the energy of liquefaction is quantified.Key words: static liquefaction, constitutive model, triaxial tests, liquefaction energy.

Afiliacje autorów:

Boukpeti N.-University of Western Australia (AU)
Mróz Z.-IPPT PAN
Drescher A.-other affiliation
4.Drescher A., Parcie i przepływ materiałów ziarnistych w wysokich zbiornikach, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.51, pp.1-255, 1979
5.Drescher A., Badanie mechanizmów plastycznego płynięcia materiałów ziarnistych (Praca habilitacyjna), Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.27, pp.1-206, 1975
6.Mróz Z., Drescher A., Hueckel T., Doskonalenie metod badania parametrów płynięcia materiałów ziarnistych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.54, pp.1-130, 1973
7.Drescher A., O pewnych rozwiązaniach kinematycznych płaskiego płynięcia ośrodków rozdrobnionych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.31, pp.1-38, 1972
8.Hueckel T., Drescher A., Nieliniowy opis deformacji sprężysto - plastycznych ciał rozdrobnionych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.65, pp.1-35, 1972
9.Drescher A., Zagadnienia doświadczalnej weryfikacji modelu ciała rozdrobnionego o wzmocnieniu gęstościowym, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.9, pp.1-77, 1971
10.Kwaszczyńska K., Mróz Z., Drescher A., Analysis of compression of short cylinders of Coulomb material, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, ISSN: 0020-7403, DOI: 10.1016/0020-7403(69)90001-0, Vol.11, No.2, pp.145-158, 1969

Streszczenie:

A static solution is presented for the case of compression of short circular cylinders between rough, rigid plates. It is assumed that the material is perfectly plastic, satisfying the Coulomb yield condition and the associated flow law. The stress state is calculated for the edge régime of the Coulomb hexagon for which the Haar-Kármán hypothesis is satisfied. The solution is obtained for several height-diameter ratios, various friction conditions at the cylinder-plate interface and for various angles of internal friction. Results of theoretical solutions are compared with available experimental data. The analysis may be useful in experimental determination of the angle of internal friction and cohesion by compressing short cylinders between rigid plates.

Afiliacje autorów:

Kwaszczyńska K.-IPPT PAN
Mróz Z.-IPPT PAN
Drescher A.-IPPT PAN
11.Mróz Z., Drescher A., Limit Plasticity Approach to Some Cases of Flow of Bulk Solids, Journal of Engineering for Industry, ISSN: 0022-1817, DOI: 10.1115/1.3591573, Vol.91, No.2, pp.357-364, 1969

Streszczenie:

Depending on the stress state, a bulk solid, regarded as the elastic-plastic material, can exhibit workhardening, worksoftening or perfectly plastic properties. During continuing motion, the solid flow can be assumed as incompressible, and the stress field satisfies a condition of critical state which can be identified with the Coulomb yield condition. The model of Coulomb material is introduced; such material satisfies the Coulomb yield condition and the flow law associated with this condition by the plastic potential rule. In general, the Coulomb material is stronger than the considered bulk solid in the critical state. The kinematic approach and the familiar upper bound theorem are applied in order to determine lower bounds on pressure exerted by the flowing material on bin walls and to determine flowability criterion. In the latter section, the flow induced by a horizontally moving rough plate is analyzed and two flow patterns are considered.

Słowa kluczowe:

Flow (Dynamics), Plasticity, Bulk solids, Coulombs, Critical points (Physics), Stress, Surface roughness, Motion, Theorems (Mathematics), Pressure

Afiliacje autorów:

Mróz Z.-IPPT PAN
Drescher A.-IPPT PAN
12.Drescher A., Kwaszczyńska K., On Approximate Description of Non-linear Viscoelastic Material, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.24, pp.1-25, 1968
13.Kwaszczyńska K., Mróz Z., Drescher A., Analiza ściskania krótkich walców z materiału Coulomba, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.29, pp.1-46, 1968
14.Drescher A., Kwaszczyńska K., Mróz Z., Statics and kinematics of the granular medium in the case of wedge indentation, ARCHIWUM MECHANIKI STOSOWANEJ, ISSN: 0373-2029, Vol.19, pp.99-113, 1967
15.Drescher A., Bojanowski W., O wpływie drogi obciążania na własności mechaniczne ośrodka idealnie sypkiego, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.20, pp.1-26, 1967

Prace konferencyjne
1.Boukpeti N., Mróz Z., Drescher A., Rate Effects in the Superior Sand Model, First Japan-U.S. Workshop on Testing, Modeling, and Simulation, 2003-06-27/06-29, Boston (US), DOI: 10.1061/40797(172)6, pp.123-135, 2003

Streszczenie:

This paper aims at analyzing the response of the elasto-viscoplastic model Superior sand proposed by Boukpeti et al. for describing rate effects in undrained loading of loosely-packed granular deposits. The equations governing the model in triaxial compression are solved for three loading histories: constant strain rate, constant stress rate, and creep. The resulting stress-strain-time curves are discussed in the light of material instability states in relation to static liquefaction. It is shown that the classical second-order work rate instability criterion is no longer valid, and a new criterion based on the deformation acceleration is presented.

Afiliacje autorów:

Boukpeti N.-University of Western Australia (AU)
Mróz Z.-IPPT PAN
Drescher A.-other affiliation