Prof. Wojciech Szczepiński, PhD, DSc


Habilitation thesis
1963Zagadnienie wzmocnienia w uogólnionym płaskim stanie naprężenia ośrodka plastycznego742
 
Professor
1971Title of professor
Other
1976Corresponding Member of Polish Academy of Sciences
1989Member of Polish Academy of Sciences

Supervision of doctoral theses
1.1978Petryk Henryk  Ustalone płaskie przepływy ośrodków idealnie plastycznych ze swobodnym brzegiem 
2.1977Woźniak Małgorzata  Równowaga graniczna skarp ziemnych. Próba rozwiązywania zagadnień przestrzennych. 
3.1976Trąmpczyński Wiesław  Mechanika procesów urabiania gruntów jako zagadnienie teorii plastyczności 
4.1974Duytien Dao  Próba twardości Rockwella jako problem teorii plastyczności 
5.1971Białkiewicz Jerzy  Efekty dynamiczne w procesach obróbki plastycznej metali 
6.1970Turski Karol  Badanie wpływu odkształcenia plastycznego na zachowanie się metalu przy różnych drogach wtórnych obciążenia 
7.1969Dietrich Lech  Teoretyczna i doświadczalna analiza nośności granicznej w zagadnieniach kontaktowych 
8.1968Drescher Ewa  Eksperymentalna analiza dynamicznego zniszczenia elementów o złożonym kształcie 
9.1967Miastkowski Józef  Wpływ historii obciążenia na powierzchnię plastyczności 

Recent publications
1.Kotulski Z., Szczepiński W., On a model for prediction of the movements of a crowd in narrow exits, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.53, No.4, pp.347-361, 2005
2.Szczepiński W., Miastkowski J., On Experimental Studies of Yield Surfaces of Metals; a more general approach, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.42, pp.1-29, 1993
3.Szczepiński W., Wesołowski Z., On Certain Methods of determining the Ellipses and Ellipsoids of the positioning Accuracy of Robot Manipulators, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.5, pp.1-24, 1992
4.Kotulski Z., Szczepiński W., On Two Methods of Determining the Ellipses and Ellipsoids of Positioning Accuracy of Robot Manipulators, Prace IPPT - IFTR Reports, ISSN: 2299-3657, DOI: 10.1007/BF00787907, No.15, pp.1-32, 1992
Abstract:

When analysing the problem of the positioning accuracy of robot manipulators it is important to know how far random deviations of the hand may be from the desired position if the joint positioning errors possess a normal distribution. Two methods of determining the ellipses and ellipsoids of probability concentration are compared. The first of them is based on the standard procedure of the probability calculus. The second approximate method consists in finding at first the polygon or polyhedron of the positioning accuracy, and then in finding the ellipse or ellipsoid with principal axes and second order moments coinciding with those of the polygon or polyhedron, respectively. Examples of application demonstrate that these two methods give very close results.

Affiliations:
Kotulski Z.-IPPT PAN
Szczepiński W.-IPPT PAN
5.Szczepiński W., A more Fundamental Approach to the Interpretation of Photoelastic Data, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.16, pp.1-35, 1991
6.Szczepiński W., Mechanics of ductile fracture treated as a problem of the theory of plasticity, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/0749-6419(90)90027-C, Vol.6, No.1, pp.11-27, 1990
Abstract:

Slip-line solutions are presented in an attempt to analyse the role of internal strain concentrations in the mechanics of ductile fracture. Interaction between variously oriented cracks leading to local microfractures is examined. Examples of simple experimental modelling substantiate theoretical analysis.

Affiliations:
Szczepiński W.-IPPT PAN
7.Szczepiński W., Analiza dokładności ustawiania kątów orientacji końcówki roboczej manipulatorów, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.45, pp.1-41, 1989
8.Szczepiński W., Analiza pól tolerancji dokładności pozycjonowania manipulatorów, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.29, pp.1-64, 1988
9.Szczepiński W., Analiza dokładności pozycjonowania manipulatorów robotów o ruchach przestrzennych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.54, pp.1-48, 1988
10.Miastkowski J., Szczepiński W., Doświadczalna analiza powierzchni wpływu plastycznego odkształcenia na wytrzymałość zmęczeniową metali, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.6, pp.1-14, 1980
11.Szczepiński W., Statically Admissible Stress Fields for Plastic Design of Connections of Steel Structures, Journal of Structural Mechanics, ISSN: 0783-6104, DOI: 10.1080/03601217908905311, Vol.7, No.1, pp.35-53, 1979
Abstract:

The technique of statically admissible plastic stress fields is used in the plastic design of complex connections -of steel structures. An appropriate stress field gives a safe estimate of the shape of the connection design. Complex three-dimensional stress fields are composed of elementary subfields. Thus the procedure of plastic design consists in appropriate arrangement of subfields into a complex system of stresses.

Affiliations:
Szczepiński W.-IPPT PAN
12.Szczepiński W., Statyczne dopuszczalne pola naprężeń dla węzłów konstrukcji stalowych, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.44, pp.1-60, 1977
13.Szczepiński W., Szlagowski J., On plastic design of complex machine parts, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, ISSN: 0020-7403, DOI: 10.1016/0020-7403(76)90013-8, Vol.18, No.7-8, pp.365-373, 1976
Abstract:

The technique of statically admissible plastic discontinuous stress fields is used in the plastic design of machine parts of complex shape. If the shape of the part is given the stress field is used to find a lower bound on the bearing capacity. In the case of plastic design an appropriate stress field gives a safe estimate of the shape of the designed part. Complex three-dimensional stress fields are composed of elementary sub-fields, all geometrical and statical parameters of which are tabulated in order to simplify the design procedure. Thus the procedure consists in appropriate arrangement of sub-fields into a complex system of stresses.

Affiliations:
Szczepiński W.-IPPT PAN
Szlagowski J.-Warsaw University of Technology (PL)
14.Szczepiński W., Szlagowski J., Graniczne statycznie dopuszczalne nieciągłe pola naprężeń dla szacowania nośności granicznej. Część IV - Tablica 10, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.3, pp.1-174, 1976
15.Szczepiński W., Szlagowski J., Graniczne statyczne dopuszczalne nieciągłe pola naprężeń dla szacowania nośności granicznej. - Część V, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.9, pp.1-204, 1976
16.Szczepiński W., Szlagowski J., Graniczne statycznie dopuszczalne nieciągłe pola naprężeń dla szacowania nośności granicznej. - Część II, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.11, pp.1-224, 1976
17.Szczepiński W., Szlagowski J., Graniczne statyczne dopuszczalne nieciągłe pola naprężeń dla szacowania nośności granicznej. - Część I, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.20, pp.1-61, 1976
18.Szczepiński W., Szlagowski J., Graniczne statycznie dopuszczalne nieciągłe pola naprężeń dla szacowania nośności granicznej. - Część III, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.21, pp.1-162, 1976
19.Marjanović R., Szczepiński W., On the effect of biaxial cyclic loading on the yield surface of M-63 brass, ACTA MECHANICA, ISSN: 0001-5970, DOI: 10.1007/BF01177669, Vol.23, pp.65-74, 1975
Abstract:

Experimental results for thirtysix thin walled tubular specimens of M-63 brass are presented in a study of the effect of biaxial cyclic loading in the first and second quadrant of the principal stress plane on the shape of the yield surfaces. These results show that tested material strained cyclically beyond the initial yield locus works under a fully elastic regime after a few cycles of the initial transitory period.

Affiliations:
Marjanović R.-other affiliation
Szczepiński W.-IPPT PAN
20.Dietrich L., Szczepiński W., A note on complete solutions for the plastic bending of notched bars, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, ISSN: 0022-5096, DOI: 10.1016/0022-5096(69)90031-3, Vol.17, No.3, pp.171-176, 1969
Abstract:

The complete solutions for the plastic bending of deeply notched bars are presented for certain configurations of the notch. Extensions of the stress fields into the rigid regions have been obtained by superimposing two fields of the type given by J.F.W. Bishop for axially loaded notched bars, or one such a field, on an uniaxially tensioned (or compressed) strip. For other shapes of the notch the method breaks down; it then gives lower bounds on the yield moment.

Affiliations:
Dietrich L.-IPPT PAN
Szczepiński W.-IPPT PAN
21.Szczepiński W., Miastkowski J., Plastic straining of notched bars with intermediate thickness and small shoulder ratio, INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS, ISSN: 0020-7462, DOI: 10.1016/0020-7462(68)90026-7, Vol.3, No.1, pp.83-97, 1968
Abstract:

Upper bounds on the yield point load factor for notched bars with finite thickness and small shoulder ratio c/h, are presented and later compared with experimental results. Five sets of specimens of aluminium alloys were tested. It was found that the yield point load generally coincides with the theoretical upper bound, although the influence of the notch geometry and ductility of the material can be observed.

Affiliations:
Szczepiński W.-IPPT PAN
Miastkowski J.-IPPT PAN
22.Szczepiński W., Miastkowski J., An experimental study of the effect of the prestraining history on the yield surfaces of an aluminium alloy, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, ISSN: 0022-5096, DOI: 10.1016/0022-5096(68)90024-0, Vol.16, No.3, pp.153-162, 1968
Abstract:

Experimental results for fifty-six specimens of an aluminium alloy are presented in a study of the effect of the prestraining path on the shape of the yield surfaces. A special experimental technique has been applied, consisting of cutting out flat specimens from the prestrained sheet material. Experimental results show that if two various loading paths have different initial sectors and a common final sector, the influence of these initial sectors on the yield surface is the smaller the longer is the final common sector. A theoretical analysis of that problem on the basis of the kinematic workhardening rule is also presented.

Affiliations:
Szczepiński W.-IPPT PAN
Miastkowski J.-IPPT PAN
23.Dietrich L., Szczepiński W., Plastic yielding of axially-symmetric bars with non-symmetric V-notch, ACTA MECHANICA, ISSN: 0001-5970, DOI: 10.1007/BF01178570, Vol.4, No.3, pp.230-240, 1967
Abstract:

The plastic incipient flow of V-notched axially symmetric bars with different slope of the two generators is considered using theTresca yield criterion and associated flow rule. The experimental results show good agreement with theoretical solutions.

Keywords:

Yield Criterion, Flow Rule

Affiliations:
Dietrich L.-IPPT PAN
Szczepiński W.-IPPT PAN
24.Szczepiński W., Miastkowski J., Plastic Straining of Notched Bars with Intermediate Thickness and Small Shoulder Ratio, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.4, pp.1-15, 1967
25.Dietrich L., Szczepiński W., Plastic Yielding of Axially-symmetric Bars with Non-symmetric V-notch, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.5, pp.1-10, 1967
26.Szczepiński W., Dietrich L., Drescher E., Miastkowski J., Plastic flow of axially-symmetric notched bars pulled in tension, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/0020-7683(66)90037-0, Vol.2, No.4, pp.543-554, 1966
Abstract:

Theoretical and experimental results are presented for plastic flow of axially symmetric notched bars. The slip-line fields have been calculated numerically using the Shield theory of axially symmetric plastic flow. The load factors obtained from the theoretical solutions differ only slightly from those for plane strain conditions. Two sets of specimens were investigated in order to obtain the actual load factors for V-shaped and rounded notches. The agreement between the theory and experimental results is satisfactory. In the last series of experiments the influence of the diameter of the bar outside the notch was investigated and later compared with the theoretically estimated value of that diameter.

Affiliations:
Szczepiński W.-IPPT PAN
Dietrich L.-IPPT PAN
Drescher E.-other affiliation
Miastkowski J.-IPPT PAN
27.Miastkowski J., Szczepiński W., An experimental study of yield surfaces of prestrained brass, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/0020-7683(65)90026-0, Vol.1, No.2, pp.189-194, 1965
Abstract:

Experimental results for twenty-eight tubular specimens of a M-63 brass, subjected to combined biaxial tension, are presented in the study of the effect of prestraining on the shape of the yield surface. Yield surfaces are found for various definitions of the yield locus. The strain increments are also shown in the stress plane in order to compare their orientation with the normality criterion. Moreover, the lengths of elastic and plastic strain increment vectors are compared at different moments of loading.

Affiliations:
Miastkowski J.-IPPT PAN
Szczepiński W.-IPPT PAN
28.Miastkowski J., Szczepiński W., Doświadczalne badanie powierzchni plastyczności wstępnie odkształconego mosiądzu, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.3, No.2, pp.55-66, 1965
Abstract:

Experimental results for twenty-eight tubular specimens of a M63 brass, subjected to combined biaxial tension are presented in the study of the effect of prestraining on the shape of the yield surface. Yield surfaces are found for various definitions of the yield locus. The strain increments are also shown in the stress plane in order to compare their orientation with the normality criterion. Moreover, the lengths of elastic and plastic strain increment vectors are compared at different moments of loading.

Affiliations:
Miastkowski J.-IPPT PAN
Szczepiński W.-IPPT PAN

List of recent monographs
1.
26
Kotulski Z., Szczepiński W., Error Analysis with Applications in Engineering, Series: Solid Mechanics and Its Applications, Springer, 169, pp.1-284, 2010
2.
120
Kotulski Z., Nowicki A., Szczepiński W., Wprowadzenie do teorii fal naprężeń i deformacji w zastosowaniach technicznych i do diagnostyki ultradźwiękowej, BEL Studio (Warszawa), pp.1-271, 2008