Results 261 to 270 of about 1,274,604 (303)
Some of the next articles are maybe not open access.
Fractional relaxation and the time-temperature superposition principle
Rheologica Acta, 1994Relaxation processes in complex systems like polymers or other viscoelastic materials can be described by equations containing fractional differential or integral operators. In order to give a physical motivation for fractional order equations, the fractional relaxation is discussed in the framework of statistical mechanics.
W. G. Gl�ckle, T. F. Nonnenmacher
openaire +1 more source
Time ? Temperature superposition for thermorheologically complex materials
Polymer Mechanics, 1975The shift factoraT for thermorheologically complex bodies is a function not only of temperature T but also of the deformation time t. A method is given for determining the vertical shift factor on the basis of macro-tests within the experimental time window.
openaire +1 more source
Creep of Geotextiles Using Time–Temperature Superposition Methods
Journal of Geotechnical and Geoenvironmental Engineering, 2004The objective of this study is to evaluate the creep deformations, creep failure, and residual tensile strength of geosynthetics using accelerated time-temperature procedures and procedures consistent with rapid tensile testing. The study proposes new definitions for the quantification of creep, of creep failure, and of the reference strength for ...
Jorge G. Zornberg +2 more
openaire +1 more source
Time-temperature superposition and linear viscoelasticity of polybutadienes
Macromolecules, 1995A series of monodisperse polybutadienes has been used to perform mechanical relaxation measurements from the flow regime to the glassy state. Results on loss shear moduli have been analyzed within the framework of a coupling model. It has been found to represent well the frequency dependence in the glassy and terminal zones using a segmental motion ...
Palade, L., Verney, Vincent, Attané, P.
openaire +2 more sources
Time-temperature superposition for block copolymers
1971The proposition is made that simple time-temperature superposition should not be valid for block copolymers exhibiting multiple mechanical transitions; and an explanation of the time temperature behavior, which is more consistent with the behavior of the individual phases, is presented in terms of an equivalent mechanical model.
openaire +1 more source
Time-Temperature Superposition in Heterophase Block Copolymers
1973The viscoelastic behavior of a styrene-butadiene-styrene block copolymer cast from several different solvents was studied in order to examine the validity of the time-temperature superposition principle in heterophase polymers. It is found that stress-relaxation isotherms over a wide temperature range can be easily superposed into smooth master curves.
A. Kaya, G. Choi, M. C. Shen
openaire +1 more source
Stress relaxation and time/temperature superposition of polypropylene fibres
Polymer, 1995The viscoelastic properties of polypropylene fibres are investigated in a single-step stress relaxation test for small strains at temperatures between −50 and + 30 °C, thus well encompassing the glass transition temperature. For the analysis of the curves a formal two-component (TC) model is applied, which comprises an elastic and a viscoelastic ...
F WORTMANN, K SCHULZ
openaire +1 more source
Time–Temperature Superposition of Phase Separating Polymer Blend Films
High Performance Polymers, 2000We have examined the structure formations in symmetric blend films of polystyrene and poly(methyl methacrylate) during phase separation and coalescence in the melt. We qualitatively verify the principle of time–temperature superposition by observing morphology development in which characteristic structures develop independently of annealing ...
D A Winesett +4 more
openaire +1 more source
Geometric Interpretation of Linear Viscoelasticity and Time-Temperature Superposition
AIP Conference Proceedings, 2008Dynamic moduli data are considered as a curve on the plane of loss tangent and storage modulus. The curve can be parameterized by the material frequency which is defined as the arc length of the curve. The relationship between real frequency and the material frequency determines the horizontal and vertical shift factors.
Kwang Soo Cho +6 more
openaire +1 more source
Time-Temperature Superposition in Linear and Non-linear Domain
Materials Today: Proceedings, 2016Long-term behavior of polymers and their composites is related mainly to their time-dependent mechanical properties, i.e. material functions or master curves, usually obtained by time-temperature superposition (tTS) principle. The “weakest” point utilizing tTS lies in “manual or hand” shifting procedure, which can lead to over- or under-estimated life ...
Alen Oseli +3 more
openaire +1 more source