Faculty of Mathematics

University of Duisburg-Essen

Email: Patrizio Neff

Tel. +49 0201 183 4243

Personal Website

Research field: Modelling & Simulation

- A review on wave propagation modeling in band-gap metamaterials via enriched continuum models
Madeo, A. and Neff, P. and Barbagallo, G. and D’Agostino, M.V. and Ghiba, I.-D.

ADVANCED STRUCTURED MATERIALS Volume: 69 (2017) - A variant of the linear isotropic indeterminate couple-stress model with symmetric local force-stress, symmetric nonlocal force-stress, symmetric couple-stresses and orthogonal boundary conditions
Ghiba, I.-D. and Neff, P. and Madeo, A. and Münch, I.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 22 (2017) - Analysis of the deformation of cosserat elastic shells using the dislocation density tensor
Bîrsan, M. and Neff, P.

ADVANCED STRUCTURED MATERIALS Volume: 69 (2017) - Hyperelastic bodies under homogeneous Cauchy stress induced by non-homogeneous finite deformations
Mihai, L.A. and Neff, P.

INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS Volume: 89 (2017) - Integrability conditions between the first and second Cosserat deformation tensor in geometrically nonlinear micropolar models and existence of minimizers
Lankeit, J. and Neff, P. and Osterbrink, F.

ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK Volume: 68 (2017) - Modeling Phononic Crystals via the Weighted Relaxed Micromorphic Model with Free and Gradient Micro-Inertia
Madeo, A. and Collet, M. and Miniaci, M. and Billon, K. and Ouisse, M. and Neff, P.

JOURNAL OF ELASTICITY (2017) - New thoughts in nonlinear elasticity theory via Hencky’s logarithmic strain tensor
Neff, P. and Martin, R.J. and Eidel, B.

ADVANCED STRUCTURED MATERIALS Volume: 69 (2017) - On the Convexity of Nonlinear Elastic Energies in the Right Cauchy-Green Tensor
Yang Gao, D. and Neff, P. and Roventa, I. and Thiel, C.

JOURNAL OF ELASTICITY Volume: 127 (2017) - On the role of micro-inertia in enriched continuum mechanics
Madeo, A. and Neff, P. and Aifantis, E.C. and Barbagallo, G. and D'Agostino, M.V.

PROCEEDINGS OF THE ROYAL SOCIETY A: MATHEMATICAL, PHYSICAL AND ENGINEERING SCIENCES Volume: 473 (2017) - Rank-one convexity implies polyconvexity for isotropic, objective and isochoric elastic energies in the two-dimensional case
Martin, R.J. and Ghiba, I.-D. and Neff, P.

PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH SECTION A: MATHEMATICS Volume: 147 (2017) - Real wave propagation in the isotropic-relaxed micromorphic model
Neff, P. and Madeo, A. and Barbagallo, G. and D'Agostino, M.V. and Abreu, R. and Ghiba, I.-D.

PROCEEDINGS OF THE ROYAL SOCIETY A: MATHEMATICAL, PHYSICAL AND ENGINEERING SCIENCES Volume: 473 (2017) - The geometrically nonlinear Cosserat micropolar shear-stretch energy. Part II: Non-classical energy-minimizing microrotations in 3D and their computational validation***
Fischle, A. and Neff, P.

ZAMM ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK (2017) - The geometrically nonlinear Cosserat micropolar shear–stretch energy. Part I: A general parameter reduction formula and energy-minimizing microrotations in 2D
Fischle, A. and Neff, P.

ZAMM ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK Volume: 97 (2017) - The relaxed-polar mechanism of locally optimal Cosserat rotations for an idealized nanoindentation and comparison with 3D-EBSD experiments
Fischle, A. and Neff, P. and Raabe, D.

ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK Volume: 68 (2017) - Transparent anisotropy for the relaxed micromorphic model: Macroscopic consistency conditions and long wave length asymptotics
Barbagallo, G. and Madeo, A. and d'Agostino, M.V. and Abreu, R. and Ghiba, I.-D. and Neff, P.

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES Volume: 120 (2017) - A new view on boundary conditions in the Grioli-Koiter-Mindlin-Toupin indeterminate couple stress model
Madeo, A. and Ghiba, I.-D. and Neff, P. and Münch, I.

EUROPEAN JOURNAL OF MECHANICS, A/SOLIDS Volume: 59 (2016) - Comparison of isotropic elasto-plastic models for the plastic metric tensor Cp = FTp Fp
Neff, P. and Ghiba, I.-D.

LECTURE NOTES IN APPLIED AND COMPUTATIONAL MECHANICS Volume: 81 (2016) - Complete band gaps including non-local effects occur only in the relaxed micromorphic model
Madeo, A. and Neff, P. and d'Agostino, M.V. and Barbagallo, G.

COMPTES RENDUS - MECANIQUE Volume: 344 (2016) - Dev-Div- and DevSym-DevCurl-inequalities for incompatible square tensor fields with mixed boundary conditions
Bauer, S. and Neff, P. and Pauly, D. and Starke, G.

ESAIM - CONTROL, OPTIMISATION AND CALCULUS OF VARIATIONS Volume: 22 (2016) - First evidence of non-locality in real band-gap metamaterials: Determining parameters in the relaxed micromorphic model
Madeo, A. and Barbagallo, G. and D'Agostino, M.V. and Placidi, L. and Neff, P.

PROCEEDINGS OF THE ROYAL SOCIETY A: MATHEMATICAL, PHYSICAL AND ENGINEERING SCIENCES Volume: 472 (2016) - Geometry of Logarithmic Strain Measures in Solid Mechanics
Neff, P. and Eidel, B. and Martin, R.J.

ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS Volume: 222 (2016) - Injectivity of the Cauchy-stress tensor along rank-one connected lines under strict rank-one convexity condition
Neff, P. and Mihai, L.A.

JOURNAL OF ELASTICITY (2016) - Loss of ellipticity for non-coaxial plastic deformations in additive logarithmic finite strain plasticity
Neff, P. and Ghiba, I.-D.

INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS Volume: 81 (2016) - Minimal geodesics on GL(n) for left-invariant, right-O(n)-invariant riemannian metrics
Martin, R.J. and Neff, P.

JOURNAL OF GEOMETRIC MECHANICS Volume: 8 (2016) - Numerical treatment of a geometrically nonlinear planar Cosserat shell model
Sander, O. and Neff, P. and Bîrsan, M.

COMPUTATIONAL MECHANICS Volume: 57 (2016) - On some fundamental misunderstandings in the indeterminate couple stress model. A comment on recent papers of A.R. Hadjesfandiari and G.F. Dargush
Neff, P. and Münch, I. and Ghiba, I.-D. and Madeo, A.

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES Volume: 81 (2016) - On the Convexity of Nonlinear Elastic Energies in the Right Cauchy-Green Tensor
Yang Gao, D. and Neff, P. and Roventa, I. and Thiel, C.

JOURNAL OF ELASTICITY (2016) - On the dislocation density tensor in the Cosserat theory of elastic shells
Bîrsan, M. and Neff, P.

ADVANCED STRUCTURED MATERIALS Volume: 60 (2016) - On the sum of squared logarithms inequality and related inequalities
Dannan, F.M. and Neff, P. and Thiel, C.

JOURNAL OF MATHEMATICAL INEQUALITIES Volume: 10 (2016) - Rediscovering GF Becker's early axiomatic deduction of a multiaxial nonlinear stress-strain relation based on logarithmic strain
Neff, P. and Münch, I. and Martin, R.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 21 (2016) - Reflection and transmission of elastic waves in non-local band-gap metamaterials: A comprehensive study via the relaxed micromorphic model
Madeo, A. and Neff, P. and Ghiba, I.-D. and Rosi, G.

JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS Volume: 95 (2016) - Soliton-like solutions based on geometrically nonlinear Cosserat micropolar elasticity
Böhmer, C.G. and Neff, P. and Seymenoğlu, B.

WAVE MOTION Volume: 60 (2016) - The Exponentiated Hencky Strain Energy in Modeling Tire Derived Material for Moderately Large Deformations
Montella, G. and Govindjee, S. and Neff, P.

JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY, TRANSACTIONS OF THE ASME Volume: 138 (2016) - The exponentiated Hencky-logarithmic strain energy: Part III—coupling with idealized multiplicative isotropic finite strain plasticity
Neff, P. and Ghiba, I.-D.

CONTINUUM MECHANICS AND THERMODYNAMICS Volume: 28 (2016) - The sum of squared logarithms inequality in arbitrary dimensions
Borisov, L. and Neff, P. and Sra, S. and Thiel, C.

LINEAR ALGEBRA AND ITS APPLICATIONS (2016) - A first regularity result for the Armstrong-Frederick cyclic hardening plasticity model with Cosserat effects
Chełmiński, K. and Neff, P. and Owczarek, S.

JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS Volume: 423 (2015) - An ellipticity domain for the distortional Henckylogarithmic strain energy
Ghiba, I.-D. and Neff, P. and Martin, R.J.

PROCEEDINGS OF THE ROYAL SOCIETY A: MATHEMATICAL, PHYSICAL AND ENGINEERING SCIENCES Volume: 471 (2015) - Band gaps in the relaxed linear micromorphic continuum
Madeo, A. and Neff, P. and Ghiba, I.-D. and Placidi, L. and Rosi, G.

ZAMM ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK Volume: 95 (2015) - Existence Theorem for Geometrically Nonlinear Cosserat Micropolar Model Under Uniform Convexity Requirements
Neff, P. and Bîrsan, M. and Osterbrink, F.

JOURNAL OF ELASTICITY Volume: 121 (2015) - On the generalised sum of squared logarithms inequality
Pompe, W. and Neff, P.

JOURNAL OF INEQUALITIES AND APPLICATIONS Volume: 2015 (2015) - Poincaré meets Korn via Maxwell: Extending Korn's first inequality to incompatible tensor fields
Neff, P. and Pauly, D. and Witsch, K.-J.

JOURNAL OF DIFFERENTIAL EQUATIONS Volume: 258 (2015) - Some remarks on the monotonicity of primary matrix functions on the set of symmetric matrices
Martin, R.J. and Neff, P.

ARCHIVE OF APPLIED MECHANICS Volume: 85 (2015) - The exponentiated Hencky-logarithmic strain energy. Improvement of planar polyconvexity
Ghiba, I. D. and Neff, P. and Silhavy, M.

INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS Volume: 71 (2015) - The Exponentiated Hencky-Logarithmic Strain Energy. Part I: Constitutive Issues and Rank-One Convexity
Neff, P. and Ghiba, I.-D. and Lankeit, J.

JOURNAL OF ELASTICITY Volume: 121 (2015) - The exponentiated Hencky-logarithmic strain energy. Part II: Coercivity, planar polyconvexity and existence of minimizers
Neff, P. and Lankeit, J. and Ghiba, I.-D. and Martin, R. and Steigmann, D.

ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK Volume: 66 (2015) - The relaxed linear micromorphic continuum: Existence, uniqueness and continuous dependence in dynamics
Ghiba, I.-D. and Neff, P. and Madeo, A. and Placidi, L. and Rosi, G.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 20 (2015) - The relaxed linear micromorphic continuum: Well-posedness of the static problem and relations to the gauge theory of dislocations
Neff, P. and Ghiba, I.D. and Lazar, M. and Madeo, A.

QUARTERLY JOURNAL OF MECHANICS AND APPLIED MATHEMATICS Volume: 68 (2015) - Wave propagation in pantographic 2D lattices with internal discontinuities
Madeoa, A. and Corte, A.D. and Greco, L. and Neff, P.

PROCEEDINGS OF THE ESTONIAN ACADEMY OF SCIENCES Volume: 64 (2015) - Wave propagation in relaxed micromorphic continua: modeling metamaterials with frequency band-gaps
Madeo, A. and Neff, P. and Ghiba, I.D. and Placidi, L. and Rosi, G.

CONTINUUM MECHANICS AND THERMODYNAMICS Volume: 27 (2015) - Well-posedness for dislocation based gradient visco-plasticity with isotropic hardening
Kraynyukova, N. and Nesenenko, S. and Neff, P. and Chełmiński, K.

NONLINEAR ANALYSIS: REAL WORLD APPLICATIONS Volume: 25 (2015) - A Logarithmic Minimization Property of the Unitary Polar Factor in the Spectral and Frobenius Norms
Neff, P. and Nakatsukasa, Y. and Fischle, A.

SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS Volume: 35 (2014) - A Riemannian approach to strain measures in nonlinear elasticity
Neff, P. and Eidel, B. and Osterbrink, F. and Martin, R.

COMPTES RENDUS - MECANIQUE Volume: 342 (2014) - A unifying perspective: The relaxed linear micromorphic continuum
Neff, P. and Ghiba, I.-D. and Madeo, A. and Placidi, L. and Rosi, G.

CONTINUUM MECHANICS AND THERMODYNAMICS Volume: 26 (2014) - Counterexamples in the theory of coerciveness for linear elliptic systems related to generalizations of Korn's second inequality
Neff, P. and Pompe, W.

ZAMM ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK Volume: 94 (2014) - Existence of minimizers in the geometrically non-linear 6-parameter resultant shell theory with drilling rotations
Bîrsan, M. and Neff, P.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 19 (2014) - New Poincaré-type inequalities
Bauer, S. and Neff, P. and Pauly, D. and Starke, G.

COMPTES RENDUS MATHEMATIQUE Volume: 352 (2014) - On an extension of the first Korn inequality to incompatible tensor fields on domains of arbitrary dimensions
Neff, P. and Pauly, D. and Witsch, K.-J.

COMPUTATIONAL METHODS IN APPLIED SCIENCES Volume: 34 (2014) - On Grioli's minimum property and its relation to Cauchy's polar decomposition
Neff, P. and Lankeit, J. and Madeo, A.

INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE Volume: 80 (2014) - On the convexity of the function C → f(det C) on positive-definite matrices
Lehmich, S. and Neff, P. and Lankeit, J.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 19 (2014) - Shells without drilling rotations: A representation theorem in the framework of the geometrically nonlinear 6-parameter resultant shell theory
Bîrsan, M. and Neff, P.

INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE Volume: 80 (2014) - The Armstrong-Frederick cyclic hardening plasticity model with Cosserat effects
Chełmiński, K. and Neff, P. and Owczarek, S.

JOURNAL OF DIFFERENTIAL EQUATIONS Volume: 256 (2014) - The minimization of matrix logarithms: On a fundamental property of the unitary polar factor
Lankeit, J. and Neff, P. and Nakatsukasa, Y.

LINEAR ALGEBRA AND ITS APPLICATIONS Volume: 449 (2014) - Existence theorems in the geometrically non-linear 6-parameter theory of elastic plates
Bîrsan, M. and Neff, P.

JOURNAL OF ELASTICITY Volume: 112 (2013) - Sum of squared logarithms-an inequality relating positive definite matrices and their matrix logarithm
Bîrsan, M. and Neff, P. and Lankeit, J.

JOURNAL OF INEQUALITIES AND APPLICATIONS Volume: 2013 (2013) - Unique continuation for first-order systems with integrable coefficients and applications to elasticity and plasticity
Lankeit, J. and Neff, P. and Pauly, D.

COMPTES RENDUS MATHEMATIQUE Volume: 351 (2013) - Uniqueness of integrable solutions to ∇ ζ=G ζ, ζ{pipe}Gamma = 0 for integrable tensor coefficients G and applications to elasticity
Lankeit, J. and Neff, P. and Pauly, D.

ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK Volume: 64 (2013) - Maxwell meets Korn: A new coercive inequality for tensor fields in R N × N with square-integrable exterior derivative
Neff, P. and Pauly, D. and Witsch, K.-J.

MATHEMATICAL METHODS IN THE APPLIED SCIENCES Volume: 35 (2012) - On a canonical extension of Korn's first and Poincaré's inequalities to H(CURL)
Neff, P. and Pauly, D. and Witsch, K.-J.

JOURNAL OF MATHEMATICAL SCIENCES (UNITED STATES) Volume: 185 (2012) - Poroplasticity with cosserat effects
Chełmiński, K. and Neff, P. and Owczarek, S.

ZAMM ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK Volume: 92 (2012) - Well-posedness for Dislocation Based Gradient Viscoplasticity I: Subdifferential Case
Nesenenko, S. and Neff, P.

SIAM JOURNAL ON MATHEMATICAL ANALYSIS Volume: 44 (2012) - A canonical extension of Korn's first inequality to H(Curl) motivated by gradient plasticity with plastic spin
Neff, P. and Pauly, D. and Witsch, K.-J.

COMPTES RENDUS MATHEMATIQUE Volume: 349 (2011) - A micropolar continuum model for large deformation caused by magnetic or electric fields
Münch, I. and Neff, P. and Wagner, W.

PROCEEDINGS OF SPIE - THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING Volume: 7978 (2011) - A viscoelastic thin rod model for large deformations: Numerical examples
Beyrouthy, J. and Neff, P.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 16 (2011) - FETI-DP domain decomposition methods for elasticity with structural changes: P-elasticity
Klawonn, A. and Neff, P. and Rheinbach, O. and Vanis, S.

ESAIM: MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS Volume: 45 (2011) - Transversely isotropic material: Nonlinear Cosserat versus classical approach
Münch, I. and Neff, P. and Wagner, W.

CONTINUUM MECHANICS AND THERMODYNAMICS Volume: 23 (2011) - Existence and uniqueness for rate-independent infinitesimal gradient plasticity with isotropic hardening and plastic spin
Ebobisse, F. and Neff, P.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 15 (2010) - Existence, uniqueness and stability in linear cosserat elasticity for weakest curvature conditions
Jeong, J. and Neff, P.

MATHEMATICS AND MECHANICS OF SOLIDS Volume: 15 (2010) - Parallel simulation of an infinitesimal elasto-plastic Cosserat model
Neff, P. and Müller, W. and Wieners, C.

GAMM MITTEILUNGEN Volume: 33 (2010) - Polyconvex Energies for Trigonal, Tetragonal and Cubic Symmetry Groups
Schröder, J. and Neff, P. and Ebbing, V.

IUTAM SYMPOSIUM ON VARIATIONAL CONCEPTS WITH APPLICATIONS TO THE MECHANICS OF MATERIALS Volume: 21 (2010) - Solving geometrically exact micromorphic elasticity with a staggered algorithm
Klawonn, A. and Neff, P. and Rheinbach, O. and Vanis, S.

GAMM MITTEILUNGEN Volume: 33 (2010) - Stable identification of linear isotropic Cosserat parameters: Bounded stiffness in bending and torsion implies conformal invariance of curvature
Neff, P. and Jeong, J. and Fischle, A.

ACTA MECHANICA Volume: 211 (2010) - The Reissner-Mindlin plate is the γ-limit of Cosserat elasticity
Neff, P. and Hong, K.-I. and Jeong, J.

MATHEMATICAL MODELS AND METHODS IN APPLIED SCIENCES Volume: 20 (2010)