scholarly journals Modeling the Full Time-Dependent Phenomenology of Filled Rubber for Use in Anti-Vibration Design

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 841 ◽  
Author(s):  
Francesca Carleo ◽  
Jan Plagge ◽  
Roly Whear ◽  
James Busfield ◽  
Manfred Klüppel
Keyword(s):  
Volume Fraction ◽  
Cyclic Stress ◽  
Full Time ◽  
Finite Element Software ◽  
Filler Volume Fraction ◽  
Filled Rubber ◽  
Component Design ◽  
Rubber Compounds ◽  
Viscoelastic Effects ◽  
Linear Viscoelastic

Component design of rubber-based anti-vibration devices remains a challenge, since there is a lack of predictive models in the typical regimes encountered by anti-vibration devices that are deformed to medium dynamic strains (0.5 to 3.5) at medium strain rates (0.5/s to 10/s). An approach is proposed that demonstrates all non-linear viscoelastic effects such as hysteresis and cyclic stress softening. As it is based on a free-energy, it is fast and easily implementable. The fitting parameters behave meaningfully when changing the filler volume fraction. The model was implemented for use in the commercial finite element software ABAQUS. Examples of how to fit experimental data and simulations for a variety of carbon black filled natural rubber compounds are presented.

Investigating the Non-Linear Viscoelastic Behavior of Filled Rubber Compounds Through Fourier Transform Rheometry

2005 ◽  
Vol 78 (1) ◽  
pp. 54-75 ◽  
Author(s):  
Jean L. Leblanc
Keyword(s):  
Fourier Transform ◽  
Volume Fraction ◽  
Viscoelastic Behavior ◽  
Viscoelastic Response ◽  
Constant Frequency ◽  
Filled Rubber ◽  
Rubber Compounds ◽  
Non Linear ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic

Abstract Fourier transform (FT) rheometry was used to investigate the non-linear viscoelastic behavior of a series of carbon black filled rubber compounds with various filler levels. Using a purposely modified commercial dynamic rheometer, i.e. the Rubber Process Analyzer RPA 2000® (Alpha Technologies), special strain sweep tests protocols were designed and performed in order to capture the actual strain and torque signals up to 500% deformation at constant frequency and temperature. FT yielded the main component and harmonics of strain and torque signals. Results show that the quality of the applied strain signal somewhat deteriorates with increasing stiffness of filled compounds, but remains excellent in the high strain region, where the non-linear viscoelastic response of the materials is investigated. Above a filler volume fraction of around 12–13%, tested materials no longer exhibit a linear viscoelastic response, at least in the strain window investigated, and the FT rheometry results are more complex than what was observed with pure gum samples. This means that most practical rubber compounds are intrinsically non-linear. By essence, FT rheometry is a valid technique for both the linear and the non-linear domains and, as shown, provides original information about complex polymer systems such as filled rubber compounds.

Updating a Torsional Dynamic Rheometer for Fourier Transform Rheometry on Rubber Materials

2003 ◽  
Vol 76 (2) ◽  
pp. 287-298 ◽  
Author(s):  
Jean L. Leblanc ◽  
Christophe de la Chapelle
Keyword(s):  
Fourier Transform ◽  
Strain Amplitude ◽  
Filler Content ◽  
Filled Rubber ◽  
Linear Behavior ◽  
Rubber Compounds ◽  
Non Linear ◽  
Linear Viscoelastic ◽  
Fourier Transform Spectrum ◽  
Fast Electronic

Abstract A torsional dynamic rheometer has been suitably modified in order to collect actual torque and strain data, in view of studying the non-linear viscoelastic region. Essentially a fast electronic analogic - digital conversion card is used to record and treat torque and strain signals using a purposely written software. A Fast Fourier Transform (FFT) algorithm was first used in order to resolve recorded signals in harmonic peak components. Preliminary investigations were conducted with pure elastomers and filled rubber compounds in order to asses the testing capabilities of the system. As expected, when the non-linear viscoelastic response of a pure, unfilled rubber is produced through increasing strain amplitude, a number of significant odd-harmonic peaks appear in the Fourier Transform Spectrum (FTS). When testing intrinsically non-linear materials such as carbon-black filled rubber compounds, FFT gives also significant odd-harmonics whose relative intensities growth with filler content. Fourier transform rheology has therefore the capability to truly investigate non-linear viscoelasticity but cannot at first sight distinguish between the non-linear behavior appearing upon increasing strain amplitude (extrinsic non-linearity) and the non-linear behavior that reflects the complex heterogeneity of the material (intrinsic non-linearity). Other data analysis techniques were thus investigated; for instance, the detail examination of the actual shape of half-period torque signals. It appears that torque signal distortions are different providing they are obtained either through larger strain amplitude tests on pure polymer or by increasing filler content.

scholarly journals Modelling the Molecular Permeation through Mixed-Matrix Membranes Incorporating Tubular Fillers

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 58
Author(s):  
Ali Zamani ◽  
F. Handan Tezel ◽  
Jules Thibault
Keyword(s):  
Aspect Ratio ◽  
Relative Permeability ◽  
Polymer Matrix ◽  
Volume Fraction ◽  
Mixed Matrix Membranes ◽  
Analytical Prediction ◽  
Mixed Matrix ◽  
Permeability Ratio ◽  
Filler Volume Fraction ◽  
Matrix Membranes

Membrane-based processes are considered a promising separation method for many chemical and environmental applications such as pervaporation and gas separation. Numerous polymeric membranes have been used for these processes due to their good transport properties, ease of fabrication, and relatively low fabrication cost per unit membrane area. However, these types of membranes are suffering from the trade-off between permeability and selectivity. Mixed-matrix membranes, comprising a filler phase embedded into a polymer matrix, have emerged in an attempt to partly overcome some of the limitations of conventional polymer and inorganic membranes. Among them, membranes incorporating tubular fillers are new nanomaterials having the potential to transcend Robeson’s upper bound. Aligning nanotubes in the host polymer matrix in the permeation direction could lead to a significant improvement in membrane permeability. However, although much effort has been devoted to experimentally evaluating nanotube mixed-matrix membranes, their modelling is mostly based on early theories for mass transport in composite membranes. In this study, the effective permeability of mixed-matrix membranes with tubular fillers was estimated from the steady-state concentration profile within the membrane, calculated by solving the Fick diffusion equation numerically. Using this approach, the effects of various structural parameters, including the tubular filler volume fraction, orientation, length-to-diameter aspect ratio, and permeability ratio were assessed. Enhanced relative permeability was obtained with vertically aligned nanotubes. The relative permeability increased with the filler-polymer permeability ratio, filler volume fraction, and the length-to-diameter aspect ratio. For water-butanol separation, mixed-matrix membranes using polydimethylsiloxane with nanotubes did not lead to performance enhancement in terms of permeability and selectivity. The results were then compared with analytical prediction models such as the Maxwell, Hamilton-Crosser and Kang-Jones-Nair (KJN) models. Overall, this work presents a useful tool for understanding and designing mixed-matrix membranes with tubular fillers.

Understanding Wet Skid Resistance Testing with the British Pendulum Skid Tester: Analysis of Sliding Noise from Various Filled Compounds

2010 ◽  
Vol 83 (1) ◽  
pp. 97-122 ◽  
Author(s):  
Xiao-Dong Pan ◽  
Paul Zakelj ◽  
Cara Adams ◽  
Akiko Neil ◽  
Greg Chaplin
Keyword(s):  
Volume Fraction ◽  
Concrete Surface ◽  
Resistance Testing ◽  
Styrene Butadiene Rubber ◽  
Skid Resistance ◽  
Butadiene Rubber ◽  
Portland Cement Concrete ◽  
Frequency Range ◽  
Rubber Compounds ◽  
Wet Skid Resistance

Abstract The British pendulum skid tester (BPST) has been widely adopted for laboratory characterization of wet skid resistance (WSR) for rubber compounds. However, testing results are not yet well explained with material properties. For filled compounds made of the same styrene-butadiene rubber, on a Portland cement concrete surface wetted with water, WSR for compounds filled with inorganic oxides is higher than WSR for compounds filled with carbon black at the same filler volume fraction. However, such difference in WSR is eliminated under ethanol lubrication. Difference in WSR remains under ethanol lubrication between compounds filled with a reinforcing filler and compounds filled with a nonreinforcing filler. Accepting that dynamic deformation of rubber occurs in the frequency range between 103 and 106 Hz during testing with the BPST, loss tangent for the compounds is measured at various low temperatures but fails to correlate with WSR detected under water lubrication. Modification of bulk viscoelasticity from ethanol absorption should not be neglected for consideration of WSR under ethanol lubrication. During testing with the BPST, sliding noise generated by the assemblage of the spring and lever system in the pendulum with a rubber slider attached is captured under varied lubrication conditions. Both viscoelastic properties of rubber compounds and lubrication condition significantly affect sliding noise. However, no strict correlation between the intensity of sliding noise and WSR is observed. From frequency domain analysis, major components of the sliding noise lie in the frequency range between 500 and 5000 Hz for most compounds. For better understanding on testing with the BPST, modes of material deformation during dynamic sliding on a wet rough surface need to be further scrutinized.

scholarly journals Microstructural Modeling and Strengthening Mechanism of TiB/Ti-6Al-4V Discontinuously-Reinforced Titanium Matrix Composite

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 827 ◽  
Author(s):  
Shuai Zhao ◽  
Yangjian Xu ◽  
Changliang Pan ◽  
Lihua Liang ◽  
Xiaogui Wang
Keyword(s):  
Finite Element ◽  
Matrix Composite ◽  
Distribution Density ◽  
Volume Fraction ◽  
Element Model ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Finite Element Software ◽  
Multiple User ◽  
Thiessen Polygon

A novel modeling method was proposed to provide an improved representation of the actual microstructure of TiB/Ti-6Al-4V discontinuously-reinforced titanium matrix composite (DRTMC). Based on the Thiessen polygon structure, the representative volume element (RVE) containing the complex microstructures of the DRTMC was first generated. Thereafter, by using multiple user-defined subroutines in the commercial finite element software ABAQUS, the application of asymmetric mesh periodic boundary conditions on the RVE was realized, and the equivalent elastic modulus of the DRTMC was determined according to the homogenization method. Through error analyses on the experimental and calculated results regarding the equivalent elastic parameters of the DRTMC, the rationality of generating the DRTMC finite element model by using the present method was validated. Finally, simulations based on four types of network-like models revealed that the present simplifications to the particle shape of the reinforcement phase had less of an influence on the overall composite strength. Moreover, the present study demonstrates that the DRTMC enhancement is mainly attributed to the matrix strengthening, rather than the load-transferring mechanism. The strengthening influences of the distribution forms of the reinforcement phases, including their distribution density and orientation, were studied further. It was found that both the higher distribution density and limited distribution orientation of the particles would increase the probability of overlapping and merging between particles, and; therefore, higher strength could be yielded when the volume fraction of the reinforcement phase reached a certain threshold. Owing to the versatility of the developed methods and programs, this work can provide a useful reference for the characterization of the mechanical properties of other composites types.

Influence of filler-rubber interactions on the viscoelastic properties of carbon-black-filled rubber compounds

2003 ◽  
Vol 91 (1) ◽  
pp. 577-588 ◽  
Author(s):  
J. Léopoldès ◽  
C. Barrès ◽  
J. L. Leblanc ◽  
P. Georget
Keyword(s):  
Carbon Black ◽  
Viscoelastic Properties ◽  
Filled Rubber ◽  
Rubber Compounds

Thermal Conductivity of Nature Rubber Filled with Carbon Black

2009 ◽  
Vol 87-88 ◽  
pp. 86-91 ◽  
Author(s):  
Yan He ◽  
Hai Tao Li ◽  
Lian Xiang Ma
Keyword(s):  
Thermal Conductivity ◽  
Carbon Black ◽  
Volume Fraction ◽  
Theoretical Models ◽  
Filled Rubber ◽  
Filler Fraction ◽  
Thermal Conductivities

The thermal conductivities of two rubbers filled with different carbon black (N330 and N375) are measured by experiments, and compared with five theoretical models calculated results. It is shown that thermal conductivity of carbon-filled rubber is obviously enhanced with increase of the volume filler fraction of carbon black and the thermal conductivity of carbon-filled rubber is related to the microstructure and morphology of carbon black. The estimated thermal conductivities by using the model proposed in our previous paper are of the same variation as the experimental ones of N330 carbon/rubber and N375 carbon/rubber during the range of volume fraction from 2% to 20%.

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