Theory of Viscoelasticity

Christensen, Richard M.; Freund, L. B.

doi:10.1115/1.3408900

Cited by 511 publications

(329 citation statements)

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“…Therefore, linear viscoelastic parameters (Aklonis & MacKnight, 2005;Christensen, 2010) such as complex shear modulus |G*| and phase angle δ, can be obtained over a wide range of temperatures and frequencies, based on a standard testing procedure. In the present study, most of DSR testing was made with a parallel-plate geometry with an 8 diameter and 2 mm gap for temperatures between − 10°C and + 40°C and a 25 diameter and 1 mm gap from + 30°C to + 80°C.…”

Section: Experimental Methodsmentioning

confidence: 99%

Effect of short-term ageing temperature on bitumen properties

Hofko

Falchetto

Grenfell

et al. 2017

Road Materials and Pavement Design

102

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Properties of asphalt mixtures after ageing are fundamental parameters in determining longterm performance (e.g. durability) of these materials. With increasing popularity of reduced temperature mixtures, such as warm-mix asphalt, WMA, the question remains how a reduction in short-term ageing affects the properties after long-term ageing of bituminous materials. This paper aims to improve our understanding of the effect of asphalt manufacturing temperature on ageing and the resulting mechanical properties of bituminous binder by studying the effect of short-and long-term ageing of different bitumen samples as a function of short-term ageing temperatures. For this purpose, round robin experiments were conducted within the RILEM technical committee (TC) 252 chemo-mechanical characterisation of bituminous materials by 10 laboratories from 5 countries using four binders of the same grade (70/100 pen) from different crude sources. The short-term ageing was carried out using the standard procedure for rolling thin film oven test (RTFOT), but varying the temperatures. Long-term ageing was carried out using the standard procedure for pressure aging vessel (PAV) in addition to RTFOT. For the mechanical characterisation, rheological data were determined by using the dynamic shear rheometer (DSR) and conventional tests, with needle penetration and softening point using the ring and ball method. The results show that although different short-term ageing temperatures showed a significant difference in the mechanical properties of the binders, these differences vanished after long-term ageing with PAV.Keywords: bitumen; DSR; long-term ageing; short-term ageing; asphalt; RTFOT; PAV IntroductionAs an organic material, bitumen undergoes changes in its mechanical characteristics, chemical composition and microstructure due to environmental effects over its lifetime (Glotova, Gorshkov, Kats, Shapiro, & Yureva, 1980;Lee, Tia, Ruth, & Page, 1997;Mills-Beale et al., 2012;Yao, Dai, & You, 2015). Loss of volatile components at elevated temperatures and oxidation are two main factors for these changes. In terms of mechanical properties, bitumen tends to become stiffer, more elastic and brittle over time. Road Materials and Pavement Design109 SARA (saturates, aromatics, resins and asphaltenes) fractions can be observed with an increasing amount of asphaltenes and decreasing amount of aromatics over time Lu & Isacsson, 2002). These changes are generally summarised under the term "ageing". Bitumen ageing can be split up into short-term and long-term ageing. In the case of hot mix asphalt, short-term ageing occurs during asphalt mix production, transport and compaction at the construction site, all of which happens within hours. It is characterised by relatively high temperatures ( > 130°C) and thus, high oxidation rates. Long-term ageing occurs in asphalt pavements in the field as a result of exposure to traffic and climatic conditions during its service life. Compared to short-term ageing, long-term ageing is a slow oxidation process tha...

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Section: Experimental Methodsmentioning

confidence: 99%

Effect of short-term ageing temperature on bitumen properties

Hofko

Falchetto

Grenfell

et al. 2017

Road Materials and Pavement Design

102

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“…In certain situations, e.g. for viscoelastic materials with an incompressibility constraint [5], it is not possible to eliminate the stress from the equations, hence the development of stable mixed elements for linear elasticity is a promising important step towards the resolution of related problems. On the other hand, mixed methods are in general robust in certain limiting situations [6][7][8], in the incompressibility limit for the elasticity equations.…”

Section: Variational Formulations Of the Elasticity Equationsmentioning

confidence: 99%

Symmetric Matrix Fields in the Finite Element Method

Awanou

2010

Symmetry

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The theory of elasticity is used to predict the response of a material body subject to applied forces. In the linear theory, where the displacement is small, the stress tensor which measures the internal forces is the variable of primal importance. However the symmetry of the stress tensor which expresses the conservation of angular momentum had been a challenge for finite element computations. We review in this paper approaches based on mixed finite element methods.

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“…Since in this case relaxation tests are not available, one needs to utilize the relation between creep compliance and relaxation modulus (Christensen, 1982;Park and Kim, 1999) …”

Section: Glass Particles/fibersmentioning

confidence: 99%

“…The constitutive equation for a linear viscoelastic material can be written in terms of Stieltjes integral equation of the form (Christensen, 1982) …”

Section: Theoretical Background For Viscoelastic Materialsmentioning

confidence: 99%

Hierarchical micromechanical modeling of the viscoelastic behavior coupled to damage in SMC and SMC-hybrid composites

Anagnostou

Chatzigeorgiou

Chemisky

et al. 2018

Composites Part B: Engineering

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThe aim of this paper is to study, through a multiscale analysis, the viscoelastic behavior of glass reinforced sheet molding compound (SMC) composites and SMC-hybrid composites mixing two types of bundle reinforcement: glass and carbon fibers. SMC exhibit more than two distinct characteristic length scales, so that a sequence of scale transitions is required to obtain the overall behavior of the composite. An analytical procedure is used consisting of properly selected well-established micromechanical methods like the Mori-Tanaka (MTM) and the composite cylinders (CCM) accounting for each scale transition. After selecting a representative volume element (RVE) for each scale, the material response of any given length scale is described on the basis of the homogenized behavior of the next finer one. This hierarchical approach is appropriately extended to the viscoelastic domain to account for the time dependent overall response of the SMC composite material. The anisotropic damage has been introduced through a micromechanical model considering matrix penny-shape microcrack density inside bundles. The capabilities of the hierarchical modeling are illustrated with various parametric studies and simulation of experimental data for glass-based SMC composites.

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Theory of Viscoelasticity

Cited by 511 publications

References 0 publications

Effect of short-term ageing temperature on bitumen properties

Effect of short-term ageing temperature on bitumen properties

Symmetric Matrix Fields in the Finite Element Method

Hierarchical micromechanical modeling of the viscoelastic behavior coupled to damage in SMC and SMC-hybrid composites

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