Partner: dr hab. Ewa Turska 

Doktorat
1990  O lokalnym uplastycznieniu otoczenia wierzchołka szczeliny w antypłaskim stanie odkształcenia
 462 
Habilitacja
20151029  Zbieżność i stabilność algorytmów numerycznych w sformułowaniach wielopolowych mechaniki 
Ostatnie publikacje
1.  Wiśniewski K., Turska E.^{♦}, Reduced representations of assumed fields for Hu–Washizu solidshell element, COMPUTATIONAL MECHANICS, ISSN: 01787675, DOI: 10.1007/s00466023022751, Vol.71, pp.957990, 2023 Streszczenie: Mixed eightnode (hexahedron) solidshell elements based on the standard or partial version of the threefield Hu–Washizu (HW) functionals are developed for Green strain. Three reduced representations of the assumed stress/strain fields are selected. They improve effectiveness, yet retaining good accuracy and convergence properties. At the outset, the standard HW functional and the assumed stress/strain representations of the 3D solid element B815P (Weissman in Int J Numer Methods Eng 39:2337–2361, 1996) are used to derive a solidshell element with 51 parameters. To eliminate locking, the ANS method is applied to the thickness strain (Betsch and Stein in Commun Numer Methods Eng 11:899–909, 1995) and to the transverse shear strain (Dvorkin and Bathe in Eng Comput 1:77–88, 1984). It is a correct element which, however, yields too large displacements for coarse meshes and trapezoidal throughthickness shapes. To improve the above formulation, the ζindependent reduced representations of the assumed stress/ strain fields are selected and the transformations to Cartesian components are modified. The thickness strain is enhanced by the EAS method. The element with 35 parameters is derived from the standard/enhanced HW functional, but, to further reduce the assumed fields, partial/enhanced HW functionals are constructed from the 3D potential energy by applying the Lagrange multiplier method only to selected strain components. In the element with 27 parameters, this is applied to the constant inplane strain and to the transverse shear strain while in the element with 19 parameters, to the constant inplane strain only.Two other modifications are implemented to enhance the behavior of these elements: (A) the skew coordinates are used in the reduced representations of the inplane stress/strain (Wisniewski and Turska in Int J Numer Methods Eng 90:506–536, 2012), and (B) the Residual Bending Flexibility correction of the transverse shear stiffness (MacNeal in Comput Struct 8(2):175–183, 1978) is adapted. Finally, the performance of the proposed solidshell HW elements is demonstrated on several linear and nonlinear examples for the linear elastic material and the hyperelastic material. The proposed elements are compared to each other and to the best existing elements of this class. Słowa kluczowe: Eightnode (hexahedron) solidshell elements , Standard or partial Hu–Washizu functionals, Reduced representations of assumed stress/strain , RBF correction Afiliacje autorów:
 140p.  
2.  Wiśniewski K., Turska E.^{♦}, Improved ninenode shell element MITC9i with reduced distortion sensitivity, COMPUTATIONAL MECHANICS, ISSN: 01787675, DOI: 10.1007/s0046601715104, Vol.62, No.3, pp.499523, 2018 Streszczenie: The 9node quadrilateral shell element MITC9i is developed for the ReissnerMindlin shell inematics, the extended potential energy and Green strain. The following features of its formulation ensure an improved behavior: 1. The MITC technique is used to avoid locking, and we propose improved ransformations for bending and transverse shear strains, which render that all patch tests are passed for the regular mesh, i.e. with straight element sides and middle positions of midside nodes and a central node. 2. To reduce shape distortion effects, the socalled corrected shape functions of Celia and Gray (Int J Numer Meth Eng 20:1447–1459, 1984) are extended to shells and used instead of the standard ones. In effect, all patch tests are passed additionally for shifts of the midside nodes along straight element sides and for arbitrary shifts of the central node. 3. Several extensions of the corrected shape functions are proposed to enable computations of nonflat shells. In particular, a criterion is put forward to determine the shift parameters associated with the central node for nonflat elements. Additionally, the method is presented to construct a parabolic side for a shifted midside node, which improves accuracy for symmetric curved edges. Drilling rotations are included by using the drilling Rotation Constraint equation, in a way consistent with the additive/multiplicative rotation update scheme for large rotations. We show that the corrected shape functions reduce the sensitivity of the solution to the regularization parameter γ of the penalty method for this constraint. The MITC9i shell element is subjected to a range of linear and nonlinear tests to show passing the patch tests, the absence of locking, very good accuracy and insensitivity to node shifts. It favorably compares to several other tested 9node elements. Słowa kluczowe: 9node shell element MITC9i, Twolevel approximation of strains, Patch tests, Corrected shape functions, Node shift parameters, Coarse mesh accuracy, Drilling rotations Afiliacje autorów:
 45p.  
3.  Panasz P., Wiśniewski K., Turska E.^{♦}, Reduction of mesh distortion effects for ninenode elements using corrected shape functions, FINITE ELEMENTS IN ANALYSIS AND DESIGN, ISSN: 0168874X, DOI: 10.1016/j.finel.2012.11.003, Vol.66, pp.8395, 2013 Streszczenie: The paper concerns twodimensional ninenode quadrilateral elements based on the Green strain and the twolevel approximations of strains. These approximations reduce locking well for regular meshes but cannot prevent the drop of accuracy when the side and central nodes are shifted from the middle positions. Słowa kluczowe: Twodimensional ninenode elements, Corrected shape functions, Twolevel approximations of strains, Patch tests, Shape distortions Afiliacje autorów:
 35p.  
4.  Wiśniewski K., Turska E.^{♦}, Fournode mixed HuWashizu shell element with drilling rotation, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 00295981, DOI: 10.1002/nme.3335, Vol.90, pp.506536, 2012 Streszczenie: In this paper, enhanced fournode shell elements with six DOFs/node based on the Hu–Washizu (HW) functional are developed for Green strain. The drilling rotation is included through the drilling rotation constraint equation. The key features of the approach are as follows. Słowa kluczowe: fournode mixed shell element with six DOFs/node, pure or partial Hu–Washizu functionals, drilling rotation, optimal representations, skew coordinates Afiliacje autorów:
 40p.  
5.  Wiśniewski K., Wagner W.^{♦}, Turska E.^{♦}, Gruttmann F.^{♦}, Fournode HuWashizu elements based on skew coordinates and contravariant assumed strain, COMPUTERS AND STRUCTURES, ISSN: 00457949, DOI: 10.1016/j.compstruc.2010.07.008, Vol.88, pp.12781284, 2010 Streszczenie: Mixed 4node elements based on the Hu–Washizu (HW) functional are developed for the representation of the assumed strain in the natural basis at the element’s center, i.e. for the contravariant transformation rule. In other aspects, the formulation is identical as in our previous paper [9], to which this note is an addendum. Słowa kluczowe: Fournode finite elements, Hu–Washizu functional, Plane stress, Mixed elements, Skew coordinates, Contravariant assumed strain Afiliacje autorów:
 32p.  
6.  Wiśniewski K., Turska E.^{♦}, Improved fournode HuWashizu elements based on skew coordinates, COMPUTERS AND STRUCTURES, ISSN: 00457949, DOI: 10.1016/j.compstruc.2009.01.011, Vol.87, pp.407424, 2009 Streszczenie: Mixed 4node elements based on the Hu–Washizu (HW) functional are developed for stress and strain representations in various coordinates, including the skew, natural and Cartesian ones. The HW functional is used in incremental form, suitable for nonlinear materials. The key features of our approach are as follows. Słowa kluczowe: 4Node finite elements, Plane stress, Incremental Hu–Washizu functional, Mixed elements, Mixed/enhanced elements, Skew coordinates Afiliacje autorów:
 32p.  
7.  Wiśniewski K., Turska E.^{♦}, Improved fournode HellingerReissner elements based on skew coordinates, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 00295981, DOI: 10.1002/nme.2343, Vol.76, pp.798836, 2008 Streszczenie: Mixed fournode elements based on the Hellinger–Reissner (HR) functional are developed for stress representations in various coordinates, including the skew, natural and Cartesian ones. The twofield HR functional is used in the classical form and in the incremental form suitable for nonlinear materials. Słowa kluczowe: fournode finite elements, incremental Hellinger–Reissner functional, assumed stress element, assumed stress/enhanced strain element, skew coordinates Afiliacje autorów:
 
8.  Wiśniewski K., Kowalczyk P., Turska E., Analytical DSA for explicit dynamics of elasticplastic shells, COMPUTATIONAL MECHANICS, ISSN: 01787675, DOI: 10.1007/s0046600600683, Vol.39, No.6, pp.761785, 2007 Streszczenie: The paper presents an analytical constitutive design sensitivity analysis (DSA) algorithm for explicit dynamics of elasticplastic finite rotation shells. Two explicit dynamical algorithms for finite rotation shells are presented, and the DSA is developed for the one formulated in terms of the rotation vector and its time derivatives, {ψ,ψ˙,ψ¨}. The hypoelastic constitutive model based on the GreenMcInnisNaghdi stress rate is used to derive an incremental algorithm in terms of ‘backrotated’ objects. The associative deviatoric HuberMises plasticity modified by plane stress conditions is implemented in the form suitable for finite rotation/small elastic strain increments. The analytical DSA is developed for the abovespecified problem, with the design derivatives calculated w.r.t. material parameters. Designdifferentiation of the dynamic algorithm and the scheme of handling the history data and the predicted values in differentiation, which is crucial in computing correct derivatives, are described. Besides, we show how to avoid Newton loops in the DSA algorithm, when such a loop is present in the constitutive algorithm. Numerical examples show that, despite a great complexity of the solution algorithm for the finiterotation elasticplastic shells, it is feasible to compute analytical design derivatives of very good accuracy. Słowa kluczowe: Explicit dynamics, Finite rotation shell, Elasticplastic material, Analytical Design Sensitivity Analysis for constitutive parameters Afiliacje autorów:
 
9.  Wiśniewski K., Turska E., Enhanced Allman quadrilateral for finite drilling rotations, COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, ISSN: 00457825, DOI: 10.1016/j.cma.2005.11.003, Vol.195, pp.60866109, 2006 Streszczenie: The paper concerns a fournode quadrilateral element based on Allman shape functions undergoing finite (unrestricted) drilling rotations, and aims at improving its accuracy and facilitating its implementation. Słowa kluczowe: New Allman shape functions for finite drilling rotations, Enhanced Assumed Displacement Gradient method for formulations with rotations, Enhanced Allman finite elements Afiliacje autorów:
 
10.  Wiśniewski K., Kowalczyk P., Turska E., On the computation of design derivatives for Huber–Mises plasticity with non‐linear hardening, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 00295981, DOI: 10.1002/nme.678, Vol.57, No.2, pp.271300, 2003 Streszczenie: This paper concerns design sensitivity analysis (DSA) for an elasto–plastic material, with material parameters depending on, or serving as, design variables. The considered constitutive model is Huber–Mises deviatoric plasticity with non‐linear isotropic/kinematic hardening, one which is applicable to metals. Słowa kluczowe: design sensitivity analysis, elasto–plastic material with non‐linear hardening, parallel finite element code Afiliacje autorów:
 
11.  Sokołowski M., TurskaKłębek E., On the Approximate Evaluation of Interaction of Cracks in Elastic Media, Rozprawy Inżynierskie, ISSN: 0867888X, Vol.31, No.1, pp.115150, 1983 Streszczenie: A method of approximate analysis is presented concerning the state of stress, and the stress intensity factors in particular, in elastic media subject to a plane state of strain and containing arbitrary arrays of cracks. In the case when ·the crack distribution is not too dense, the method proposed makes possible the determination of the required stress parameters in a manner resembling that used in solving the statically indeterminate systems of structural mechanics. Afiliacje autorów:
 
12.  Turska E., Stacjonarny ruch szczeliny w polu sił skupionych, Prace IPPT  IFTR Reports, ISSN: 22993657, No.21, pp.136, 1981 
Lista rozdziałów w ostatnich monografiach
1. 637  Wiśniewski K., Turska E.^{♦}, Analysis of Shells, Plates, and Beams: A State of the Art Report, rozdział: On Transverse Shear Strains Treatment in NineNode Shell Element MITC9i, Springer, pp.421440, 2020  
2. 613  Wiśniewski K., Turska E.^{♦}, Recent Developments in the Theory of Shells, rozdział: On Performance of NineNode Quadrilateral Shell Elements 9EAS11 and MITC9i, Springer, pp.711725, 2019  
3. 507  Wiśniewski K., Turska E.^{♦}, Shelllike Structures. Advanced Theories and Applications, rozdział: Selected topics on mixed/enhanced fournode shell elements with drilling rotation, Springer International Publishing, 572, pp.247288, 2017  
4. 51  Wiśniewski K., Turska E.^{♦}, Shelllike Structures. Nonclassical Theories and Applications, rozdział: Recent Improvements in HuWashizu Shell Elements with Drilling Rotations, Springer, pp.391412, 2011 
Abstrakty konferencyjne
1.  Wiśniewski K., Turska E.^{♦}, Recent improvements to ninenode shell element MITC9 with drilling rotations, SSTA 2017, Shell Structures: Theory and Applications, 20171011/1013, Gdańsk (PL), Vol.4, pp.399402, 2018 Streszczenie: The paper describes our improved 9node quadrilateral shell element MITC9i, which is derived for the ReissnerMindlin shell kinematics, the extended potential energy functional and Green strain. 1. The MITCi technique is used to avoid locking and it is based on the improved transformations proposed in (Wisniewski & Panasz 2013) for a membrane element. Here, these transformations are extended to bending/twisting and transverse shear shell strains. 2. To reduce the shape distortion effects, the socalled corrected shape functions (CSF) of (Celia & Gray 1984) are used instead of the isoparametric ones, and we propose the method of computation the shift parameters for nonflat shell elements. 3. The drilling rotations are included via the drilling Rotation Constraint and the penalty method. This rotation is used in the multiplicative/additive update scheme valid for large (unrestricted) rotations. The effect of the MITC9i technique and the CSF is that all three patch tests are passed, also for shifted side nodes along the straight edges and for arbitrary shifts of an interior node. The MITC9i shell element was subjected to a range of linear and nonlinear numerical tests described in (Wisniewski & Turska 2017); here we provide additional examples illustrating its accurate and robust behavior. Słowa kluczowe: 9node shell element MITC9,twolevel approximation of strains, corrected shape functions, node shift parameters, drilling rotations Afiliacje autorów:
 
2.  Wiśniewski K., Turska E.^{♦}, Recent results on ninenode shell elements using twolevel approximation of strain, SolMech 2016, 40th Solid Mechanics Conference, 20160829/0902, Warszawa (PL), No.P122, pp.12, 2016 Słowa kluczowe: finite element method, shell elements Afiliacje autorów:
 
3.  Wiśniewski K., Turska E.^{♦}, Recent improvements in mixed/enhanced shell elements with drilling rotation, SolMech 2014, 39th Solid Mechanics Conference, 20140901/0905, Zakopane (PL), pp.2728, 2014  
4.  Wiśniewski K., Turska E.^{♦}, On mixed/enhanced HuWashizu shell elements with drilling rotation, SSTA, 10th Jubilee Conference on Shell Structures  Theory and Applications, 20131016/1018, Gdańsk (PL), DOI: 10.1201/b15684117, Vol.3, pp.469472, 2014 Streszczenie: Mixed/enhanced fournode shell elements with six dofs/node based on the HuWashizu (HW) functional are developed for Green strain. The shell HW functional is derived from the shell potential energy functional instead of from the threedimensional HW functional. Partial HW functionals, differing in the bending/twisting part and the transverse shear part, are obtained. For the membrane part of HW shell elements, a 7parameter stress, a 9parameter strain and a 2parameter EADG enhancement are selected as performing best. The assumed representations of stress and strain are defined in skew coordinates in the natural basis at the element's center. The drilling rotation is included through the drilling Rotation Constraint (RC) equation and the Perturbed Lagrange method. The spurious mode is stabilized using the gamma method. Several versions of shell HW elements are tested using several benchmark examples and the optimally performing element is selected (HW29) in (Wisniewski & Turska 2012). Afiliacje autorów:
 
5.  Wiśniewski K., Turska E.^{♦}, On Shell Elements Derived from HuWashizu Functional, SolMech 2012, 38th Solid Mechanics Conference, 20120827/0831, Warszawa (PL), pp.228229, 2012  
6.  Wiśniewski K., Kowalczyk P., Turska E., DSA for Elasticplastic Shells and Explicit Dynamics, 8th U.S. National Congress on Computational Mechanics, 20050724/0728, Austin, Texas (US), No.1681, pp.1, 2005 Słowa kluczowe: design sensitivity analysis, finite element method, shell structures, elastoplasticity Afiliacje autorów:
 
7.  Wiśniewski K., Kowalczyk P., Turska E., DSA for elasticplastic finite rotation shells under dynamic loads, ICTAM XXI, 21st International Congress of Theoretical and Applied Mechanics, 20040815/0821, Warszawa (PL), No.12679, pp.361, 2004 Słowa kluczowe: Design sensitivity analysis, finite element method, finite rotations, shell elements Afiliacje autorów:
 
8.  Wiśniewski K., Kowalczyk P., Turska E., DSA for elasticplastic finite rotation shells under dynamic loads, ICTAM04, 21st International Congress of Theoretical and Applied Mechanics, 20040815/0821, Warszawa (PL), No.12679, pp.12, 2004 Streszczenie: The paper describes a constitutive algorithm for elasticplastic finite rotation shells and explicit dynamics with design derivatives calculated w.r.t. We show that despite a great complexity of the solution algorithm for the finiterotation elasticplastic shells, it is feasible to compute analytical design derivative of this algorithm, and the yielded sensitivities are of very good accuracy. Słowa kluczowe: design sensitivity analysis, finite elment method, shell structures, dynamics, finite rotations Afiliacje autorów:
