On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory

We study the smoothness properties of relaxation function such that a linear viscoelastic material system by Maxwell Boltzmann can be considered of Kelvin Voigt type; assuming that the relaxation function and its derivative decrease rapidly, and that the infinitesimal strain history is an analytical...

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Дата:1999
Автор: Matarazzo, G.
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Опубліковано: Інститут математики НАН України 1999
Назва видання:Нелінійні коливання
Онлайн доступ:http://dspace.nbuv.gov.ua/handle/123456789/177156
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Цитувати:On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory / G. Matarazzo // Нелінійні коливання. — 1999. — Т. 2, № 3. — С. 345-351. — Бібліогр.: 7 назв. — англ.

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spelling irk-123456789-1771562021-02-12T01:25:59Z On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory Matarazzo, G. We study the smoothness properties of relaxation function such that a linear viscoelastic material system by Maxwell Boltzmann can be considered of Kelvin Voigt type; assuming that the relaxation function and its derivative decrease rapidly, and that the infinitesimal strain history is an analytical function, the Cauchy stress tensor of the linear viscoelasticity is well approximated by a constitutive functional of rate type. Вивчаються властивостi гладкостi релаксацiйної функцiї для випадку, коли лiнiйно пружна за Максвеллом Больцманом матерiальна система може розглядатись як система типу Кельвiна Войгта. У припущеннi, що релаксацiйна функцiя та її похiдна швидко спадають, а iнфiнiтезiмальна функцiя деформацiї є аналiтичною, показано, що тензор напруження Кошi в лiнiйнiй теорiї пружностi добре апроксимується складовим (конститутивним) функцiоналом коефiцiєнтного типу. 1999 Article On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory / G. Matarazzo // Нелінійні коливання. — 1999. — Т. 2, № 3. — С. 345-351. — Бібліогр.: 7 назв. — англ. 1562-3076 http://dspace.nbuv.gov.ua/handle/123456789/177156 517.958 en Нелінійні коливання Інститут математики НАН України
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
language English
description We study the smoothness properties of relaxation function such that a linear viscoelastic material system by Maxwell Boltzmann can be considered of Kelvin Voigt type; assuming that the relaxation function and its derivative decrease rapidly, and that the infinitesimal strain history is an analytical function, the Cauchy stress tensor of the linear viscoelasticity is well approximated by a constitutive functional of rate type.
format Article
author Matarazzo, G.
spellingShingle Matarazzo, G.
On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
Нелінійні коливання
author_facet Matarazzo, G.
author_sort Matarazzo, G.
title On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
title_short On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
title_full On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
title_fullStr On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
title_full_unstemmed On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory
title_sort on a relation between memory effects by maxwell - boltzmann and kelvin - voigt in linear viscoelastic theory
publisher Інститут математики НАН України
publishDate 1999
url http://dspace.nbuv.gov.ua/handle/123456789/177156
citation_txt On a relation between memory effects by Maxwell - Boltzmann and Kelvin - Voigt in linear viscoelastic theory / G. Matarazzo // Нелінійні коливання. — 1999. — Т. 2, № 3. — С. 345-351. — Бібліогр.: 7 назв. — англ.
series Нелінійні коливання
work_keys_str_mv AT matarazzog onarelationbetweenmemoryeffectsbymaxwellboltzmannandkelvinvoigtinlinearviscoelastictheory
first_indexed 2025-07-15T15:11:13Z
last_indexed 2025-07-15T15:11:13Z
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fulltext т. 2 •№ 3 • 1999 УДК 517 . 958 ON A RELATION BETWEEN MEMORY EFFECTS BY MAXWELL BOLTZMANN AND KELVIN VOIGT IN LINEAR VISCOELASTIC THEORY∗ ПРО ЗВ’ЯЗОК МIЖ ЕФЕКТАМИ ПАМ’ЯТI ЗА МАКСВЕЛЛОМ БОЛЬЦМАНОМ ТА КЕЛЬВIНОМ ВОЙГТОМ В ЛIНIЙНIЙ ТЕОРIЇ ПРУЖНОСТI G. Matarazzo Univ. Salerno, 84084, Fisciano (Salerno), Italy We study the smoothness properties of relaxation function such that a linear viscoelastic material system by Maxwell Boltzmann can be considered of Kelvin Voigt type; assuming that the relaxation function and its derivative decrease rapidly, and that the infinitesimal strain history is an analytical function, the Cauchy stress tensor of the linear viscoelasticity is well approximated by a constitutive functional of rate type. Вивчаються властивостi гладкостi релаксацiйної функцiї для випадку, коли лiнiйно пружна за Максвеллом Больцманом матерiальна система може розглядатись як система типу Кельвi- на Войгта. У припущеннi, що релаксацiйна функцiя та її похiдна швидко спадають, а iн- фiнiтезiмальна функцiя деформацiї є аналiтичною, показано, що тензор напруження Кошi в лiнiйнiй теорiї пружностi добре апроксимується складовим (конститутивним) функцiоналом коефiцiєнтного типу. 1. As is posed in evidence in the study of the quasistatic problem in linear viscoelasticity theory [1,2] the crucial point for a good and exaustive formulation of viscoelastic materials theories [3,4] consists in the determination of general and physically admissible conditions [5] so that materials with more fading or negligible memory effects can be classified by a good approximation as particular viscoelastic materials; these conditions must be in accordance with the structural properties [6, 7] of viscoelastic materials and with the pattern that describes them. This problem is resolved partially in [5, 6], were have been formulated conditions, with the above properties, so that materials of linear elastic type can be considered as particular linear viscoelastic materials. Purpose of the present paper is to prove that materials of linear rate type can be considered as particular viscoelastic materials; if stronger smoothness hypotheses of relaxation and Boltzmann functions are verified and if the infinitesimal strain history is an analytic function, it is possible to approximate the constitutive functional of linear viscoelasticity theory by a particular constitutive equation of Kelvi Voigt type. It is interesting to observe that the coefficient of the memory term of this constitutive * This research has been performed under the auspices of the G.N.F.M. of the C.N.R. and has been partially supported by Italian Ministry of University and Technology Research M.U.R.S.T. c© G. Matarazzo, 1999 345 relation is equal to the value of the dynamic viscosity tensor, when the frequency w approaches to zero, where this tensor has an eliminable discontinuity in virtue of the assumed hypothe- ses [5]. Finally we conclude proving an existence and uniqueness theorem for the quasistatic problem of material systems expounded by the above functional; the solution is determined as limit of a solution of the quasistatic problem for a strictly viscoelastic material system when w → 0 [6]. 2. Let β be a linear viscoelastic and homogeneous material system described by the following constitutive functional: T (x, t) = G0(x)E(x, t) + +∞∫ 0 G′(x, s)Et(x, s)ds = = G∞(x)E(x, t) + +∞∫ 0 [G(x, s)−G∞(x)] Ėt(x, s)ds, (1) T (x, t) = T T (x, t), (x, t) ∈ Ω× [0,+∞) = Q, where T (x, s) is the Cauchy stress tensor, G(x, s) and G′(x, s) are respectively the relaxation and Boltzmann fourth-order Cartesian tensors, G0(x) and G∞(x) denote respectively the instantaneous and equilibrium elastic moduli, that are so defined: G0(x) = lim s→0 G(x, s) = G(x, s)− s∫ 0 G′(x, τ)dτ, G∞(x) = lim s→+∞ G(x, s) = G0(x) + +∞∫ 0 G′(x, τ)dτ ; E(x, t) = 1 2 [ ∇u+ (∇u)T ] , where u(x, t) denotes the displacement vector, is the second-order infinitesimal strain tensor, whileEt(x, s) = E(x, t− s), s ∈ [0,+∞) with respect to every fixed t ∈ [0,+∞), denotes the history of the infinitesimal strain tensor at instant t; finally Ω is an open and bounded domain of R3 with sufficiently regular boundary ∂Ω. We assume that the following hypotheses are verified ∀x ∈ Ω: sG′(x, s) ∈ L1(0,+∞), G(x, ·)−G∞(x) = − ∞∫ s G′(τ)dτ ∈ H1,1(0,+∞) ∩H1,2(0,+∞), lim s→+∞ s2 [G(x, s)−G∞(x)] = 0; G(x, s) = −G(x,−s) G′(x, s) = G′(x,−s) ∀s ∈ [0,+∞). (2) 346 ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 If and only ifG0(x) = G∞(x), then, for all t > 0 lim a→+∞ +∞∫ −at a [ G ( x, t+ y a ) −G∞(x) ] [sin y − y cos y y2 ] dy = 0, where y = a(s− t) and a > 0. 1. It is assumed that G′(x, ·) is continuous ∀x ∈ Ω while G′′(x, ·) is piecewise continuous; furthermore G′(x, ·) verifies Dini condition in every point of discontinuity and in a neighbourhood of such pointsG′′(x, ·) is bounded. 2. The fourth-order symmetric tensors G0(x) and G∞(x) are positive definite and continuous in Ω; furthermore G(x, ·) and G′(x, ·) are continuous in Ω with respect to every fixed s. We remark that conditions (3)1,2,3 are all verified if we suppose: ∃ α ≥ 3: lim s→∞ sα+1G′(s) = 0. (3) By the assumed hypotheses we can state the following: Theorem 1. If hypoteses (2) hold and if (3) holds by a suitable value of α and ifE(x, t− s) ∈ ∈ H1,1(0,+∞)∩H1,2(0,+∞) ∀x ∈ Ω is an analytic function, then the body β is of Kelvin Voigt type, i.e.: T (x, t) = G∞(x)E(x, t) +K(x)Ė(x, t) ∀(x, t) ∈ Ω× [0, dpα), dpα < +∞, (4) whereK(x) = +∞∫ 0 [G(x, s)−G∞(x)]ds is such that: β1A : A > −A : +∞∫ 0 sG′(x, s)dsA = A : K(x)A > β2A : A > 0 ∀x ∈ Ω, ∀A ∈ Sym(V ) \ {0}, (5) and β1, β2 are positive constants. Proof. By Maclaurin formula we have: Et(x, s) = E(x, t) + (−s)Ė(x, t) + σ(x, s2) ∀x ∈ Ω, (6) where lim s→0 σ(x, s) s2 = 0. Using (6) we can rewrite (1)1, by a suitable value of t, in this manner: T (x, t) = G0(x)E(x, t) + t∫ 0 G′(x, s) [ E(x, t)− sĖ(x, t) ] ds+ + +∞∫ t G′(x, s) [ E(x, t)− sĖ(x, t) + σ(x, s2) ] ds; (7) ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 347 remarking that, in the assumed hypotheses, it is possible to replace the limit of the integral with the integral of the limit, and that, within a linear theory, we have that: lim t→+∞ G′(x, s) [ E(x, t)− sĖ(x, t) + σ(x, s2) ] = 0 ∀x ∈ Ω; if we pass to the limit of the last integral of (7) with t→ +∞, finally by a suitable value of α in (3) and by the analiticity hypothesis of Et(x, s) we have that: T (x, t) = G∞(x)E(x, t)− +∞∫ 0 sG′(x, s)dsĖ(x, t) = G∞(x)E(x, t)+ + +∞∫ 0 [G(x, s)−G∞(x)] dsĖ(x, t) ∀ (x, t) ∈ Ω× [0, dpα), dpα < +∞, (8) that implies (4) setting K(x) = +∞∫ 0 [G(x, s)−G∞(x)] ds; finally (5) is a consequence of theorem IV of [5], because we get ∀x ∈ Ω β1A : A > A : lim w→0 Ĝc(x, w)A = −A : +∞∫ 0 sG′(x, s)dsA = = A : +∞∫ 0 [G(x, s)−G∞(x)] dsA > β2A : A, where Ĝc(x, w) = +∞∫ 0 [G(x, s)−G∞(x)] coswsds is the dynamic viscosity tensor. By the above theorem, the theorem I VI of [5] and the definitions I, II of [6] we are able to complete the examination of viscoelastic materials, that have stronger or weaker or negligible memory, formulating the following definitions: Definition 1. A continuum material system expressed by the constitutive functional (1) is said strictly viscoelastic if and only if, in hypotheses (2), the following conditions are verified: i)G(x, ·)−G0(x) 6∈ L1(0,+∞) ∀x ∈ Ω,G(x, s) = GT (x, s) ∀(x, s) ∈ Ω× [0,+∞); ii) there exist two constants µ1 > µ2 > 0, such that: µ1A : A > A : [G0(x)−G∞(x)]A > µ2A : A ∀A ∈ Sym(V ) \ {0} and ∀x ∈ Ω, where Sym(V ) is the second-order Cartesian symmetric tensor space of R3; iii) the dynamic viscosity tensor Ĝc(x, w) = +∞∫ 0 [G(x, s)−G∞(x)] coswsds is positive definite and bounded, i.e. there exist two constants β1 > β2 > 0, independent of w, such that: β1A : A > A : Ĝs(x, w)A > β2A : A ∀A ∈ Sym(V ) \ {0}, ∀ w ∈ (−∞,+∞) and ∀ x ∈ Ω; 348 ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 particularly, ∀x ∈ Ω, we have: β1A : A > A : lim w→0 Ĝc(x, w)A = −A : +∞∫ 0 sG′(x, s)dsA = = A : +∞∫ 0 [G(x, s)−G∞(x)] dsA > β2A : A and lim w→±∞ Ĝc(x, w) = 0; iv) ∀x ∈ Ω, ∀A ∈ Sym(V ) \ {0}, ∃ν1, ν2 > 0 such that: A : [ G0(x) + Ĝ ′ c(x, w) ] A = A : [ G∞(x) + wĜs(x, w) ] A ≥ ν1A : A ∀ w ∈ R, w2A : Ĝc(x, w)A = −wĜ ′ s(x, w) ≥ ν2A : A ∀ w 6= 0, where Ĝ ′ c(x, w) = +∞∫ 0 G′(x, s) coswsds, Ĝs(x, w) = +∞∫ 0 [G(x, s)−G∞(x)] sinwsds, Ĝ ′ s(x, w) = +∞∫ 0 G′(x, s) sinwsds and ν1, ν2 don’t depend on w, particularly, ∀x ∈ Ω, we have: A : lim w→0 [ G0(x) + Ĝ ′ c(x, w) ] A = A : lim w→0 [ G∞(x) + wĜs(x, w) ] A = = A : G∞(x)A ≥ ν1A : A, A : lim w→±∞ [ G0(x) + Ĝ ′ c(x, w) ] A = A : lim w→±∞ [ G∞(x) + wĜs(x, w) ] A = = A : G0(x)A > ν1A : A. Definition 2. If and only if G(x, ·) − G0(x) 6∈ L1(0,+∞) ∀x ∈ Ω, a continuum material system described by the constitutive functional (1) is a linear viscoelastic body of Kelvin Voigt type, if by hypotheses of theorem 1 the following conditions are verified: i) T (x, t) = G∞(x)E(x, t)+K(x)Ė(x, t) ∀(x, t) ∈ Ω× [0, dpα), dpα < +∞, whereK(x) = = +∞∫ 0 [G(x, s)−G∞(x)] ds is such that: β1A : A > A : lim w→0 Ĝc(x, w)A = −A : +∞∫ 0 sG′(x, s)dsA = = A : +∞∫ 0 [G(x, s)−G∞(x)] dsA > β2A : A ∀ x ∈ Ω, ∀A ∈ Sym(V ) \ {0} and β1, β2 are positive constants; ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 349 ii)G(x, s) = GT (x, s) ∈ Ω× [0,+∞). Definition 3. If hypotheses (2) hold, and if and only if G(x, ·)−G∞(x),G(x, ·)−G0(x) ∈ ∈ L1(0,+∞) ∀x ∈ Ω, body β is of linear elastic type, i.e. T (x, t)−G0(x)E(x, t) = G∞(x)E(x, t) ∀ t ∈ [0, Tc) where Tc < +∞; if and only if T (x) = G0(x)E(x) = G∞(x)E(x) then body β is linear elastic. 3. The quasistatic problem for a strictly viscoelastic body expressed by definition 1 is formulated by the following Dirichlet problem: ∇ · G∞(x)∇u(x, t) + +∞∫ 0 [G(x, s)−G∞(x)]∇u̇t(x, s) ds + b(x, t) = = ∇ · G∞(x)∇u(x, t)+ +∞∫ 0 G′(x, s)∇ut(x, s) ds + b(x, t)=0, (x, t) ∈ Q, (9) u(x, t) ∣∣ ∂Ω = 0, where u(x, t) = u(x, t)− u∞(x), lim t→+∞ u(x, t) = u∞(x), b(x, t) = b(x, t)− b∞(x) and lim t→+∞ b(x, t) = b∞(x). Relating to this problem we have proved [6] the following Theorem 2. If and only if body β is strictly viscoelastic according to definition 1, if b(x, t) ∈ ∈ L1(R;H1,2(Ω)) ∩ L2(R;H1,2(Ω)), b(x, ·) ∈ S∞(R) and has compact support in R, there exists one and only one solution with compact support u(x, t) ∈ H1,1(R;H1,2(Ω))∩H1,2(R;H1,2(Ω)), u(x, ·) ∈ S∞(R), such that: ∫ Ω′ G∞(x)∇u(x, t) + +∞∫ 0 [G(x, s)−G∞]∇u̇t(x, s) ds  : ∇H(x,x′, t)dx′ = = ∫ Ω′ G0(x)∇u(x, t) + +∞∫ 0 G′(x, s)∇ut(x, s) ds ∇H(x,x′, t) dx′ = = ∫ Ω′ b(x, t)H(x,x′, t)dx′ ∀H(x,x′, t) ∈ L∞(−∞,+∞;H1,2(Ω)×H1,2(Ω′)) : H(x,x′, t) ∣∣ ∂Ω = 0, (10) 350 ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 whereH(x,x′, t) is strongly measurable, if x′ 6= x, and S∞(R) denote the class of infinitely many time differentiable functions u(x, t) with respect to t for which there exists a set of constants Cpq, dependent on same function u(x, t) and on numbers p and q, such that:∫ Ω ∣∣∣tp∂(q) t u(x, t) ∣∣∣2 dx < C2 pq, ∫ Ω ∣∣∣tp∂(q) t ∇u(x, t) ∣∣∣2 dx < C2 pq. In [6] we verify that (10) holds if we inversely transform by Fourier the solution of the Fourier transformed problem of (9); this solution is null outside at a compact interval of the time origin, because of a condition of compatibility with the meaning itself of the quasistatic problem. This consideration and definition 2 imply that a solution of the quasistatic problem for a viscoelastic body descrebed by definition 2 must be determined as limit of this Fourier inverse transformed solution when w → 0. Consequently we can state relating to the Dirichlet problem: ∇ · G∞(x)∇u(x, t) + +∞∫ 0 [G(x, s)−G∞(x)] ds∇u̇(x, t) + b(x, t) = = ∇ · G∞(x)∇u(x, t)− +∞∫ 0 sG′(x, s)ds∇u̇(x, t) +b(x, t)=0, (x, t) ∈ Ω× [0, dpα), dpα <∞, (11) u(x, t) ∣∣ ∂Ω = 0, the following Theorem 3. If body β is a linear viscoelastic material system according to definition 2, if b(x, t) ∈ L2(Iα;H1,2(Ω)), where Iα = [0, dpα), is analytic and has compact support, only null solution solves the problem (11). 1. Fichera G. Avere una memoria tenace crea gravi problemi // Arch. Ration. Mech. and Anal. 1979. 70. P. 101 112. 2. Fichera G. Sul principio della memoria evanescente // Rend. Mat. Univ. Padova. 1982. 68. P. 245 259. 3. Coleman B.D., Noll W. Foundation of linear viscoelasticity // Rev. Modern Phisics. 1961. 33. P.239 249. 4. Green A.E., Rivlin R.S. The mechanics of nonlinear material with memory // Arch. Ration. Mech. and Anal. 1957 1958. 1. P. 1 21. 5. Matarazzo G. Symmetry of relaxation function in viscoelasticity // Proc. Int. Sci. Conf. "Asymptotic and Qualitative Methods of Nonlinear Mechanics"(Kiev, August 1997). 6. Matarazzo G. Time unreversal and existence and uniqueness problems in linear viscoelasticity // Ukr. Math. J. (To appear). 7. Rivlin R.S. A note on the Onsager Casimir relations // J. Appl. Math. and Phys. 1973. 24. P. 897 900. Received 22.03.99 ISSN 1562-3076. Нелiнiйнi коливання, 1999, т. 2, № 3 351