Search results for "UE"

showing 10 items of 55990 documents

A Model for Low-Cycle Fatigue in Micro-Structured Materials

2019

A microscale formulation for low-cycle fatigue degradation in heterogeneous materials is presented. The interface traction-separation law is modelled by a cohesive zone model for low-cycle fatigue analysis, which is developed in a consistent thermodynamic framework of elastic-plastic-damage mechanics with internal variables. A specific fatigue activation condition allows to model the material degradation related to the elastic-plastic cyclic loading conditions, with tractions levels lower than the static failure condition. A moving endurance surface, in the classic framework of kinematic hardening, enables a pure elastic behaviour without any fatigue degradation for low levels of cyclic tra…

010101 applied mathematics020303 mechanical engineering & transportsMaterials science0203 mechanical engineeringMechanics of MaterialsMechanical EngineeringMicromechanicsGeneral Materials ScienceLow-cycle fatigue02 engineering and technology0101 mathematicsComposite material01 natural sciencesKey Engineering Materials
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A Thermodynamically Consistent CZM for Low-Cycle Fatigue Analysis

2018

A cohesive zone model for low-cycle fatigue analysis is developed in a consistent thermodynamic framework of elastic-plastic-damage mechanics with internal variable. A specific fatigue activation condition allows to model the material degradation related to the elastic-plastic cyclic loading conditions, with tractions levels lower than the damage activation condition. A moving endurance surface, in the classic framework of kinematic hardening, enables a pure elastic behavior without any fatigue degradation for low levels loading conditions.

010101 applied mathematics020303 mechanical engineering & transportsMaterials science0203 mechanical engineeringMechanics of MaterialsMechanical EngineeringThermodynamicsGeneral Materials ScienceLow-cycle fatigue02 engineering and technology0101 mathematics01 natural sciencesStrength of materialsKey Engineering Materials
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The convective eigenvalues of the one–dimensional p–Laplacian as p → 1

2020

Abstract This paper studies the limit behavior as p → 1 of the eigenvalue problem { − ( | u x | p − 2 u x ) x − c | u x | p − 2 u x = λ | u | p − 2 u , 0 x 1 , u ( 0 ) = u ( 1 ) = 0 . We point out that explicit expressions for both the eigenvalues λ n and associated eigenfunctions are not available (see [16] ). In spite of this hindrance, we obtain the precise values of the limits lim p → 1 + ⁡ λ n . In addition, a complete description of the limit profiles of the eigenfunctions is accomplished. Moreover, the formal limit problem as p → 1 is also addressed. The results extend known features for the special case c = 0 ( [6] , [28] ).

010101 applied mathematicsApplied Mathematics010102 general mathematicsp-LaplacianLimit (mathematics)0101 mathematicsEigenfunction01 natural sciencesAnalysisEigenvalues and eigenvectorsMathematicsMathematical physicsJournal of Mathematical Analysis and Applications
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Symmetric and finitely symmetric polynomials on the spaces ℓ∞ and L∞[0,+∞)

2018

We consider on the space l∞ polynomials that are invariant regarding permutations of the sequence variable or regarding finite permutations. Accordingly, they are trivial or factor through c0. The analogous study, with analogous results, is carried out on L∞[0,+∞), replacing the permutations of N by measurable bijections of [0,+∞) that preserve the Lebesgue measure.

010101 applied mathematicsCombinatoricsMathematics::CombinatoricsLebesgue measureSymmetric polynomialGeneral Mathematics010102 general mathematics0101 mathematicsInvariant (mathematics)Bijection injection and surjection01 natural sciencesMathematicsMathematische Nachrichten
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A singularly perturbed Kirchhoff problem revisited

2020

Abstract In this paper, we revisit the singularly perturbation problem (0.1) − ( ϵ 2 a + ϵ b ∫ R 3 | ∇ u | 2 ) Δ u + V ( x ) u = | u | p − 1 u in  R 3 , where a , b , ϵ > 0 , 1 p 5 are constants and V is a potential function. First we establish the uniqueness and nondegeneracy of positive solutions to the limiting Kirchhoff problem − ( a + b ∫ R 3 | ∇ u | 2 ) Δ u + u = | u | p − 1 u in  R 3 . Then, combining this nondegeneracy result and Lyapunov-Schmidt reduction method, we derive the existence of solutions to (0.1) for ϵ > 0 sufficiently small. Finally, we establish a local uniqueness result for such derived solutions using this nondegeneracy result and a type of local Pohozaev identity.

010101 applied mathematicsIdentity (mathematics)Reduction (recursion theory)Applied Mathematics010102 general mathematicsUniquenessFunction (mathematics)Limiting0101 mathematics01 natural sciencesAnalysisMathematicsMathematical physicsJournal of Differential Equations
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Global Existence for Nonlinear Parabolic Problems With Measure Data– Applications to Non-uniqueness for Parabolic Problems With Critical Gradient ter…

2011

Abstract In the present article we study global existence for a nonlinear parabolic equation having a reaction term and a Radon measure datum: where 1 < p < N, Ω is a bounded open subset of ℝN (N ≥ 2), Δpu = div(|∇u|p−2∇u) is the so called p-Laplacian operator, sign s ., ϕ(ν0) ∈ L1(Ω), μ is a finite Radon measure and f ∈ L∞(Ω×(0, T)) for every T > 0. Then we apply this existence result to show wild nonuniqueness for a connected nonlinear parabolic problem having a gradient term with natural growth.

010101 applied mathematicsNonlinear systemGeneral Mathematics010102 general mathematicsMathematical analysisNon uniquenessStatistical and Nonlinear Physics0101 mathematics01 natural sciencesMeasure (mathematics)MathematicsVolume (compression)Advanced Nonlinear Studies
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L∞-variational problems associated to measurable Finsler structures

2016

Abstract We study L ∞ -variational problems associated to measurable Finsler structures in Euclidean spaces. We obtain existence and uniqueness results for the absolute minimizers.

010101 applied mathematicsPure mathematicsApplied Mathematics010102 general mathematicsEuclidean geometryMathematics::Metric GeometryUniqueness0101 mathematics01 natural sciencesAnalysisMathematicsNonlinear Analysis
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The uniform convergence of a double sequence of functions at a point and Korovkin-type approximation theorems

2020

Abstract In this paper, we introduce an interesting kind of convergence for a double sequence called the uniform convergence at a point. We give an example and demonstrate a Korovkin-type approximation theorem for a double sequence of functions using the uniform convergence at a point. Then we show that our result is stronger than the Korovkin theorem given by Volkov and present several graphs. Finally, in the last section, we compute the rate of convergence.

010101 applied mathematicsPure mathematicsGeneral MathematicsUniform convergence010102 general mathematicsPoint (geometry)0101 mathematicsType (model theory)01 natural sciencesDouble sequenceMathematicsGeorgian Mathematical Journal
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Inverse problems for $p$-Laplace type equations under monotonicity assumptions

2016

We consider inverse problems for $p$-Laplace type equations under monotonicity assumptions. In two dimensions, we show that any two conductivities satisfying $\sigma_1 \geq \sigma_2$ and having the same nonlinear Dirichlet-to-Neumann map must be identical. The proof is based on a monotonicity inequality and the unique continuation principle for $p$-Laplace type equations. In higher dimensions, where unique continuation is not known, we obtain a similar result for conductivities close to constant.

010101 applied mathematicsunique continuation principleMathematics - Analysis of PDEsinverse problems010102 general mathematicsFOS: MathematicsDirichlet-to-Neumann map35J92 35R300101 mathematics01 natural sciencesp-Laplace equationinversio-ongelmatAnalysis of PDEs (math.AP)
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Efficient generation of restricted growth words

2013

A length n restricted growth word is a word w=w"1w"2...w"n over the set of integers where w"1=0 and each w"i, i>1, lies between 0 and the value of a word statistics of the prefix w"1w"2...w"i"-"1 of w, plus one. Restricted growth words simultaneously generalize combinatorial objects as restricted growth functions, staircase words and ascent or binary sequences. Here we give a generic generating algorithm for restricted growth words. It produces a Gray code and runs in constant average time provided that the corresponding statistics has some local properties.

010102 general mathematicsBinary numberValue (computer science)0102 computer and information sciences[ MATH.MATH-CO ] Mathematics [math]/Combinatorics [math.CO]01 natural sciencesComputer Science ApplicationsTheoretical Computer SciencePrefixCombinatoricsGray code010201 computation theory & mathematics[MATH.MATH-CO]Mathematics [math]/Combinatorics [math.CO]Signal ProcessingPartial word0101 mathematicsConstant (mathematics)ComputingMilieux_MISCELLANEOUSWord (group theory)Information SystemsMathematicsInformation Processing Letters
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