Stress-Strain Behavior of Swollen Polymeric Networks

1969 ◽  
Vol 42 (2) ◽  
pp. 572-579
Author(s):  
A. M. Rijke ◽  
G. L. Taylor
Keyword(s):  
Free Energy ◽  
Volume Fraction ◽  
Molar Free Energy ◽  
Stress Strain ◽  
Strain Behavior ◽  
Crosslinked Polymer ◽  
Polymeric Networks ◽  
Stress Strain Relation ◽  
Single Term ◽  
The One

Abstract The network parameters of swollen, solution-crosslinked polymer filaments can be collected from deswelling measurements in solutions of nonpermeating polymer or, as shown in this paper, from the stress—strain relation when in equilibrium with the surrounding solvent. The degree of swelling, at which the partial molar free energy of elasticity equals zero, is found to vary with solvent power in agreement with earlier findings on other systems. Comparison with results of studies on rubber networks crosslinked in the absence of diluent, show that previously observed discrepancies between theory and experiment can be attributed to the deficiency of the single term involving the one-third power of the volume fraction of polymer in the swollen network to describe the contribution of the partial elastic free energy.

Departures of the Elastic Behavior of Rubbers in Simple Extension from the Kinetic Theory

1955 ◽  
Vol 28 (1) ◽  
pp. 24-35 ◽  
Author(s):  
S. M. Gumbrell ◽  
L. Mullins ◽  
R. S. Rivlin
Keyword(s):  
Kinetic Theory ◽  
Volume Fraction ◽  
Single Parameter ◽  
Elastic Behavior ◽  
Simple Extension ◽  
Stress Strain ◽  
Equilibrium Stress ◽  
Strain Behavior

Abstract It is shown that the equilibrium stress-strain behavior of highly swollen rubber vulcanizates in simple extension agrees with the predictions of the kinetic theory. The departures from these predictions which are found in dry or lightly swollen rubbers have been investigated, and it is shown that they can be described in terms of a single parameter C2. The magnitude of this parameter is large in dry rubbers, and decreases to zero at high degrees of swelling ; this decrease occurs linearly with decrease in the volume fraction of rubber. The value of C2 is found to be independent of the nature of the rubber polymer, of the degree of vulcanization, and of the nature of the swelling liquid. The possible significance of this parameter is discussed in light of these observations.

scholarly journals Mechanical Strength Evaluation of Elastic Materials by Multiphysical Nondestructive Methods: A Review

2020 ◽  
Vol 10 (5) ◽  
pp. 1588 ◽  
Author(s):  
Huiting Huan ◽  
Lixian Liu ◽  
Andreas Mandelis ◽  
Cuiling Peng ◽  
Xiaolong Chen ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Optical Radiation ◽  
Defect Formation ◽  
State Of The Art ◽  
Compressive Loading ◽  
Stress Strain ◽  
Strength Evaluation ◽  
Strain Behavior ◽  
Stress Strain Relation ◽  
The Stability

The main purpose of industrial nondestructive testing (NDT) is to diagnose the stability, reliability and failure probability of materials, components and structures. Industrial component mechanical strength is one of the most important properties NDT is used to characterize. Subtle but perceptible changes in stress-strain behavior can be reliable indicators of defect formation. A detailed review on the state-of-the-art NDT methods using optical-radiation, photoacoustic, and photothermal techniques for mechanical strength evaluation and defect pre-diagnosis is presented in this article. Mechanical strength is analyzed in terms of the deformation/strain field, the stress-strain relation, and the residual stress in an elastic material subjected to tensile or compressive loading, or impact. By introducing typical NDT experiments, the history and features of each methodology are revisited and typical applications are discussed. This review also aims to be used as a reference toward further research and development of NDT technologies characterizing mechanical strength of materials and components.

Modeling of stress-strain relation of cement-treated sand under compression

2021 ◽  
Author(s):  
Khawaja Adeel Tariq ◽  
Takeshi Maki
Keyword(s):  
Research Work ◽  
Fixed Ratio ◽  
Uniaxial Stress ◽  
Limestone Powder ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior ◽  
Stress Strain Relation ◽  
Uniaxial Compressive Stress

AbstractThis research work has been conducted to model the uniaxial stress-strain compressive behavior of cement-treated sand and its post-peak softening area. The cylindrical specimens were produced by using limestone powder, sand and high early strength cement. The mixtures were made by using different ratios of water to cement with fixed ratio of limestone powder to cement and cement to sand. The stress-strain behavior in post-peak zone of cement-treated is adjusted with introduction of compression softening factor. Uniaxial compressive stress-strain relationships after amending the Japanese Society of Civil Engineers model are proposed. Finite element analysis shows that the suggested model estimates well the compressive behavior of cement-treated sand.

Biodegradable polyhydroxybutyrate as a polyol for elastomeric polyurethanes

2012 ◽  
Vol 66 (9) ◽  
Author(s):  
Lucy Vojtová ◽  
Vojtěch Kupka ◽  
Jan Žídek ◽  
Jaromír Wasserbauer ◽  
Petr Sedláček ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Volume Fraction ◽  
Stress Strain ◽  
Strain Behavior ◽  
Feed Stock ◽  
Measured Stress ◽  
Strain Data ◽  
Polyether Polyol ◽  
Filled Composite

AbstractIn the proposed work, new elastomeric bio-polyol based polyurethanes (bio-PUs) with specific mechanical properties were prepared by a one-shot process without the presence of a solvent. Commercial non-degradable polyether polyol derived from petrochemical feed stock was partly (in the amount of 1 mass %, 5 mass %, and 10 mass %) substituted by the biodegradable polyhydroxybutyrate (PHB). Morphology of elastomeric PU composites was evaluated by scanning electron microscopy and mechanical properties of the prepared samples were obtained by both tensile measurements and prediction via the Mooney-Rivlin equation. Electron microscopy proved that the prepared materials have the character of a particle filled composite material, where PHB particles are regular with their size of about 1–2 μm in diameter. Tensile measurements demonstrated that the Young’s modulus, tensile stress at break, and tensile strain at break of each sample increase with the increase of the volume fraction of the filler. From the measured stress-strain data, the first and the second term of the Mooney-Rivlin equation were calculated. The obtained constants were applied to recalculate the stress-strain curves. It was found that the Mooney-Rivlin equation corresponds well with the stress-strain behavior of the prepared specimens.

Study of the Yielding and Strain Hardening Behavior of a Copper Thin Film on a Silicon Substrate Using Microbeam Bending

2001 ◽  
Vol 673 ◽  
Author(s):  
Jeffrey N. Florando ◽  
William D. Nix
Keyword(s):  
Strain Hardening ◽  
Room Temperature ◽  
Stress And Strain ◽  
Stress Strain ◽  
Strain Behavior ◽  
Hardening Behavior ◽  
Stress Strain Relation ◽  
Cu Film ◽  
Beam Bending ◽  
Strain Hardening Behavior

ABSTRACTRecently a new microbeam bending technique utilizing triangular beams was introduced. For this geometry, the film on top of the beam deforms uniformly when the beams are deflected, unlike the standard rectangular geometry in which the bending is concentrated at the support. The yielding behavior of the film can be modeled using average stress-strain equations to predict the stress-strain relation for the film while attached to its substrate. This model has also been used to show that the gradint of stress and strain through the thickness of the film, which occurs during beam bending, does not obscure the measurement of the yield stress in our analysis.Utilizing this technique, the yielding and strain hardening behavior of bare Cu thin films has been investigated. The Cu film was thermally cycled from room temperature to 500 °C, and from room temperature to –196°C. The film was tested after each cycle. The thermal cycles were performed to examine the effect of thermal processing on the stress-strain behavior of the film.

An Analysis of Longitudinal Elastic-Plastic Pulse Propagation

1966 ◽  
Vol 33 (2) ◽  
pp. 248-255 ◽  
Author(s):  
R. J. Clifton ◽  
S. R. Bodner
Keyword(s):  
Pulse Propagation ◽  
Pure Aluminum ◽  
General Shape ◽  
Stress Strain ◽  
One Dimensional ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Commercially Pure ◽  
Strain Axis ◽  
The One

The one-dimensional, rate-independent theory of elastic-plastic wave propagation for smooth stress-strain curves concave toward the strain axis is applied to the problem of a long uniform bar loaded at one end by a pressure pulse of short duration. The essential features of the solution are obtained for the case of a semi-infinite bar and for the case of a finite bar whose other end is stress-free by using the method of characteristics in the t-x plane. The general shape of boundaries in the t-x plane which separate regions governed by the dynamic elastic equations from regions governed by the dynamic plastic equations is presented. The nature of the discontinuities that occur at these boundaries is also discussed. For the finite-bar case the analysis is given for materials which exhibit isotropic work hardening and for materials for which the stress-strain behavior in tension is independent of any previous compression. The main features of the solution are in agreement with the behavior observed for annealed, commercially pure aluminum bars subjected to explosive loading at one end. These experiments will be reported subsequently.

Characterization of the Behavior of Rubber for Engineering Design Purposes. 1. Stress-Strain Relations

1994 ◽  
Vol 67 (4) ◽  
pp. 716-728 ◽  
Author(s):  
C. K. L. Davies ◽  
Dilip K. De ◽  
A. G. Thomas
Keyword(s):  
Engineering Design ◽  
Pure Shear ◽  
Deformation Mode ◽  
Analytical Form ◽  
Stress Strain ◽  
Strain Behavior ◽  
Stress Strain Relation ◽  
Strain Invariant ◽  
Filled Rubbers ◽  
Simple Deformation

Abstract The stress-strain behavior of a range of black-filled rubbers has been studied in extension, compression, pure shear and simple shear. The data have been analyzed to examine the validity of Gregory's hypothesis that the stored energy function U of filled rubbers can be expressed solely in terms of the strain invariant I1, ignoring I2, to an accuracy adequate for most engineering design requirements. Our results confirm his suggestion. An analytical form for U is proposed which gives a very good fit to the experimental data for strains from less than 0.1% to somewhat greater than 100%, which cover the range of interest for most engineering applications. The dependencies of the parameters in the expression for U on filler level and degree of crosslinking have been examined. It has thus been demonstrated that, for a given material, the form of U can be determined from the measured stress-strain relation in any simple deformation mode, shear or tension for example, without the necessity of relatively difficult biaxial measurements, and that this function should then be applicable to any deformation mode, complex or simple.

scholarly journals Mechanical Properties of Fiber Reinforced Lightweight Concrete Containing Surfactant

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Yoo-Jae Kim ◽  
Jiong Hu ◽  
Soon-Jae Lee ◽  
Byung-Hee You
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Lightweight Aggregate ◽  
Unit Weight ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Stress Strain ◽  
Strain Behavior ◽  
Toughness Index

Fiber reinforced aerated lightweight concrete (FALC) was developed to reduce concrete's density and to improve its fire resistance, thermal conductivity, and energy absorption. Compression tests were performed to determine basic properties of FALC. The primary independent variables were the types and volume fraction of fibers, and the amount of air in the concrete. Polypropylene and carbon fibers were investigated at 0, 1, 2, 3, and 4% volume ratios. The lightweight aggregate used was made of expanded clay. A self-compaction agent was used to reduce the water-cement ratio and keep good workability. A surfactant was also added to introduce air into the concrete. This study provides basic information regarding the mechanical properties of FALC and compares FALC with fiber reinforced lightweight concrete. The properties investigated include the unit weight, uniaxial compressive strength, modulus of elasticity, and toughness index. Based on the properties, a stress-strain prediction model was proposed. It was demonstrated that the proposed model accurately predicts the stress-strain behavior of FALC.

scholarly journals Shock wave speed and stress-strain relation of aluminium honeycombs under dynamic compression

2018 ◽  
Vol 183 ◽  
pp. 01047
Author(s):  
Peng Wang ◽  
Jun Zhang ◽  
Haiying Huang ◽  
Zhijun Zheng ◽  
Jilin Yu
Keyword(s):  
Shock Wave ◽  
Impact Velocity ◽  
Wave Speed ◽  
Dynamic Compression ◽  
Stress Strain ◽  
One Dimensional ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
The One ◽  
The Impact

The propagation of layer-wise crushing bands in cellular materials under dynamic impact can be described by the plastic shock wave model. A cell-based finite element model of irregular aluminum honeycomb is constructed to carry out several constant-velocity compression tests. The shock wave speed is obtained by the one-dimensional stress distribution in the specimen along the loading direction. The relation between the shock wave speed and impact velocity is obtained and analyzed. It is found that the relation tends to be linear with the increase of the impact velocity. But the shock wave speed tends to be a constant value with the decrease of the impact velocity. A piecewise model is proposed to describe the dynamic stress-strain relation of aluminum honeycombs based on a piecewise hypothesis of the relation between the shock wave speed and the impact velocity together with the one-dimensional shock wave theory. Different stress-strain relations corresponding to different impact velocity regions and different deformation modes are obtained.

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