2 edition of An investigation to simulate the linear viscoelastic behavior of an elastomer found in the catalog.
Written in English
|Contributions||Naval Postgraduate School (U.S.)|
|The Physical Object|
|Pagination||1 v. :|
Upon being crosslinked sufficiently, a chemical molecular network (rubber or elastomer) is formed that transforms the polymer into a viscoelastic solid, which does not flow. Like its precursor polymer, the viscoelastic properties are strongly dependent on time or frequency, temperature, pressure, and the presence of swelling solvent or filler. The presented work deals with the creation of a new radial basis function artificial neural network-based model of dynamic thermo-mechanical response and damping behavior of thermoplastic elastomers in the whole temperature interval of their entire lifetime and a wide frequency range of dynamic mechanical loading. The created model is based on experimental results of dynamic mechanical Author: Ivan Kopal, Marta Harničárová, Jan Valíček, Jan Krmela, Ondrej Lukáč.
Elastic and viscoelastic behaviour. When an elastic (not elastomeric, or long range elastic) material is stressed, there is an immediate and corresponding strain response. Figure 43 illustrates this by showing schematically the strain response to a particular stress history. Note that when the stress is removed the strain also returns to zero. This is also a ﬁrst order, linear ordinary differential equa-tion representing a two-parameter (E and!) viscoelastic behavior. For a given stress (or strain), Eq. () can be solved for the corresponding strain (or stress). Notice that springs are used to represent the elastic solid behavior, and there is a limit to how much a spring can File Size: KB.
Elastic behavior versus viscoelastic behavior The difference between elastic materials and viscoelastic materials is that viscoelastic materials have a viscosity factor and the elastic ones don’t. Because viscoelastic materials have the viscosity factor, they . non-linear dynamic behavior that is covered by the models suggested in this thesis. The focus is idea is to create an individual viscoelastic model for each amplitude. For each amplitude, the Since the dynamic properties of rubber are more or less non-linear, it is not entirely appropri
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An investigation to simulate the linear viscoelastic behavior of an elastomer. Item Preview remove-circle An investigation to simulate the linear viscoelastic behavior of an elastomer.
by Citerley, Richard L. Publication date Topics Mechanical engineering CollectionPages: Enter the password to open this PDF file: Cancel OK. File name:. For vibration and shock isolation investigations the conventional engineering representation of an elastomer under shear is a mechanical model with a spring and a dashpot in parallel.
To represent more adequately the dynamic behavior of an elastomer, more complex model configurations are : Richard L. Citerley. Rheological behavior of a filled elastomer consisting of a polyurethane rubber and granular potassium chloride was investigated with both long‐ and short‐term loading producing conditions of torsion, uniaxial tension, and compression.
The volumetric response and the thermo‐rheological behavior of the elastomer was also studied. To represent the observed behavior for moderate Cited by: We explore filler reinforcement (i.e., increase of elastic modulus G‘ due to incorporation of fillers) and Payne effect (i.e., decrease of G‘ at large strain amplitudes) in terms of the matrix molecular weight, filler loading, and time scales used to probe the viscoelasticity of filled melts.
Use of monodisperse non-cross-linked 1,4-polybutadiene (PBD) along with a silica filler allows Cited by: Studies on the nonlinear viscoelastic behaviors of nylon toughened with styrene‐[ethylene‐(ethylene‐propylene)]‐styrene block copolymer (SEEPS) were carried out.
The linear viscoelastic behaviors of nylon blends toughened with (styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer) (SEEPS) elastomer were carried out. silicone elastomer sample. The storage modulus was normalized for comparative purposes.
It can be seen in the figure above that the polystyrene sample has a much longer linear region as compared to the filled elastomer. After finding the linear region, subsequent scans should be conducted at amplitudes within the linear viscoelastic Size: 80KB.
broad consideration of the nonlinear flow behavior of polymers is eschewed herein, with consideration limited primarily to aspects unique to elastomers and filler-reinforced rubber. Linearity and the superposition principle The problem of analyzing viscoelastic mechanical behavior is Author: C.
Roland. depends on time. Linear viscoelastic materials are those for which there is a linear relationship between stress and strain (at any given time). Linear viscoelasticity is a theory describing the behaviour of such ideal materials.
Strain-time curves for various constant stresses are shown in the following figure for a linear viscoelastic Size: KB. In the present study different approaches for determination of the limits of linear viscoelastic (LVE) behavior are considered on examples of some thermoplastic and thermosetting polymers.
Stress or strain level, commonly considered as a limit of LVE behavior, are interrelated time-dependent functions strongly influenced by action of external by: Viscoelastic Behavior Generic Viscoelasticity: exhibition of both viscous and elastic properties, depending on the time scale over which an external stress is applied Specific Effects: Dilatancy: viscosity increases with the rate of shear (“shear-thickening”) Pseudo-plasticity: viscosity decreases with.
The viscoelastic behavior of elastomers manifests itself in numerous ways depending on the application. In seals, the viscoelastic response of an elastomer is complex as it depends upon the specific combination of loading pressures, loading rates, chemical environment, temperature and time of loading, and ultimately long-term effects such as creep or stress relaxation can result in seal by: 1.
The 4e of The Science and Technology of Rubber provides a broad survey of elastomers with special emphasis on materials with a rubber-like elasticity.
As in previous editions, the emphasis remains on a unified treatment of the material, exploring chemical aspects such as elastomer synthesis and curing, through recent theoretical developments and characterization of equilibrium and dynamic properties.
elastomer material reacts with a varying response depending on the strain rate. Dynamic testing was proposed to enable the creation of a viscoelastic portion of the overall elastomer material model.
The hyperelastic + viscoelastic material model will represent the nonlinear elastic and strain-rate dependencies of the overall material Size: KB. The goal of present article is to simulate the behavior of viscoelastic materials. By using ABAQUS software, we can simulate the behavior of viscoelastic materials, conditional to calculate storing shear module and wasting module of viscoelastic materials by the test.
First, we give descriptions required parameters such as shear module and loss factor in order to anticipate the behavior of Author: Nader Mohammadi, Mehrdad Nasirshoaibi. Linear viscoelasticity is the simplest response of a viscoelastic material.
When A classical approach to the description of the linear viscoelastic behavior of real aiming to simulate the evolution of the linear relaxation modulus of real materials. Thus, the Burgers model isFile Size: KB.
The linear viscoelastic model presented in this work is based on a linear elastic model for the MUDEA extended to account for viscous effects by the elastic–viscoelastic correspondence principle. The model is easily implemented because it is based on explicit expressions which can be evaluated numerically by any computer algebra by: 4.
Examples and Applications of Viscoelastic Materials Some of the properties of viscoelastic materials are their ability to creep, recover, undergo stress relaxation and absorb energy. Some examples of these phenomena are discussed in this section1.
Creep and Recovery The disks in the human spine are Size: 21KB. The nonlinear viscoelastic model used for the description of the mechanical behavior of the dielectric elastomer is presented in section 3.
In section 4 the FE models for the analysis of the experiments are outlined along with the procedure for determining the material parameters from curve fitting and optimization by:. The BB-model is a very powerful material model for predicting the non-linear viscoelastic response of elastomer-like materials.
The BB-model is already a native material model in Abaqus and ANSYS, but the PolyUMod implementation of this model supports. The second section deals with measurement of linear viscoelasticity (experimental aspects), and the third section deals with phenomenological models such as spring–dashpot and parsimonious models.
The last section is devoted to molecular theories of polymer viscoelasticity in linear Cited by: In this lecture following topics have covered: Introduction to Viscoelastic Materials Stress-Strain relationship Mechanical/Rheological models such as - Linear elastic spring Linear .