Asymmetric relaxation and compliance matrices in linear viscoelasticity

Zusammenfassung Die Beschränkungen, welche die Symmetrie des Materials den Nachgiebigkeitsmatrizen anisotroper viskoelastischer Stoffe auferlegt, werden ohne Bezug auf thermodynamisch bedingte Symmetrien abgeleitet. Experimente zur Überprüfung der thermodynamischen Theorien lassen sich auf die Unterschiede gründen, die zwischen den mit oder ohne Annahmen über Matrix-Symmetrie erhaltenen Formen bestehen. Transversale Isotropie und kubische Symmetrie werden im Detail behandelt.

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This paper was prepared under Contract No. 562(10) with the Office of Naval Research.     

On monotonicity in parametric linear complementarity problems

This paper generalizes the answers that were given by R.W. Cottle to questions that were originally raised by G. Maier.Essentially, we give necessary and sufficient conditions for some notions of monotonicity of solutions for the parametric linear complementarity problem. Our proofs are direct ones and not algorithmic, as Cottle's proofs are, and also cover a broader class of matrices.     

On monotonicity and boundedness properties of linear multistep methods

In this paper an analysis is provided of nonlinear monotonicity and boundedness properties for linear multistep methods. Instead of strict monotonicity for arbitrary starting values we shall focus on generalized monotonicity or boundedness with Runge-Kutta starting procedures. This allows many multistep methods of practical interest to be included in the theory. In a related manner, we also consider contractivity and stability in arbitrary norms.

     

On the monotonicity properties of additive representation functions, II

For a set A of positive integers and any positive integer n, let R₁(A,n), R₂(A,n) and R₃(A,n) denote the number of solutions of a+a^′=n with the additional restriction a,a^′∈A; a,a^′∈A,a<a^′ and a,a^′∈A,a≤a^′ respectively. In this paper, we specially focus on the monotonicity of R₃(A,n). Moreover, we show that there does not exist any set A⊂N such that R₂(A,n) or R₃(A,n) is eventually strictly increasing.     

Radial symmetry and monotonicity for an integral equation

In this paper we study radial symmetry and monotonicity of positive solutions of an integral equation arising from some higher-order semilinear elliptic equations in the whole space Rn. Instead of the usual method of moving planes, we use a new Hardy-Littlewood-Sobolev (HLS) type inequality for the Bessel potentials to establish the radial symmetry and monotonicity results.     

Strong monotonicity of operator functions

LetA, B be bounded selfadjoint operators on a Hilbert space. We will give a formula to get the maximum subspace such that is invariant forA andB, and . We will use this to show strong monotonicity or strong convexity of operator functions. We will see that when 0≤A≤B, andB−A is of finite rank,A ^t ≤B ^t for somet>1 if and only if the null space ofB−A is invariant forA.     

On the monotonicity of some functionals in the family of univalent functions

LetS denote the class of regular and univalent functions in |z|<1 with the normalizationf(0)=0,f′(0)=1. Denoted _f=inf _f∈s {|α||f(z)≠ α, |z|<1} and letS(d)={f¦f∈S,d _f=d, 1/4≦d≦1}. The analytic functionf(z) is univalent in |z|<1 if and only if $$log\frac{{f(z) - f(\zeta )}}{{z - \zeta }} = \sum\limits_{m,n = 0}^\infty {d_{mn} z^m \zeta ^n } $$ converges in the bicylinder |z|<1, |ξ|<1. LetC _mn =√mnd _mn andC _nn (d)= Max _fεS(d){Re(C _nn )}. The paper deals with the monotonicity ofc _nn(d) and related functionals.     

Complete monotonicity of some functions involving polygamma functions

In the present paper, we establish necessary and sufficient conditions for the functions x^α|ψ⁽ⁱ⁾(x+β)| and α|ψ⁽ⁱ⁾(x+β)|−x|ψ⁽ⁱ⁺¹⁾(x+β)| respectively to be monotonic and completely monotonic on (0,∞), where i∈N, α>0 and β≥0 are scalars, and ψ⁽ⁱ⁾(x) are polygamma functions.     

Shock structure in viscoelasticity of relaxation type

We are concerned with the shock structure in viscoelasticity of rate type. The existence of a shock profile, which in the vanishing relaxation limit becomes an elastic shock, is demonstrated by an explicit construction of the solution of viscoelastic equations provided that the equilibrium stress–strain relation is governed by a parabolic law. For a more general stress–strain law which does not differ substantially from a parabolic one, the solution is obtained from a perturbation expansion.     

一些特殊函数的完全单调性

欧拉Gamma函数是一种非常重要的函数,在数学的许多分支以及物理、工程等学科中都有着十分重要的作用.而完全单调性以及对数完全单调性是Gamma函数的重要性质.主要证明了一些包含Gamma函数和Psi函数在内的特殊函数的完全单调性和对数完全单调性,并由此推出了一些重要的不等式.     

A monotonicity property of bessel functions

Some monotonicity results are given for the remainder terms in the asymptotic expansion for x → ∞ of the function J_v(x)J_v+n(x) + Y_v(x Y_v+n(x), v ε R, n ε Z.     

Stability and exponential stability in linear viscoelasticity

In this survey paper, we discuss the decay properties of the semigroup generated by a linear integro-differential equation in a Hilbert space, which is an abstract version of the equation ${\partial_{tt}}u(t) - \Delta u(t) + {\int_0^\infty} \mu(s) \Delta u(t - s) {\rm{d}}s = 0$ describing the dynamics of linearly viscoelastic bodies.     

On the continuous dependence in linear anisotropic viscoelasticity on exterior domains

Adoperando il metodo della funzione peso, si dimostrano teoremi di unicità e dipendenza continua per le soluzioni della teoria dinamica della viscoelasticità lineare anisotropa nei domini esterni.     

Complete monotonicity and logarithmically complete monotonicity properties for the gamma and psi functions

We present some complete monotonicity and logarithmically complete monotonicity properties for the gamma and psi functions. This extends some known results due to S.-L. Qiu and M. Vuorinen.