Modeling Payne effect on basis of linearization of a visco-hyperelastic model

2021 ◽  
Author(s):  
Safia BOUZIDI ◽  
Hocine BECHIR
Keyword(s):  
Characteristic Property ◽  
Nonlinear Viscoelasticity ◽  
Loss Modulus ◽  
Dynamic Strain ◽  
Material Microstructure ◽  
Payne Effect ◽  
Proposed Model ◽  
Storage And Loss Moduli ◽  
Hyperelastic Model ◽  
Complex Young’S Modulus

Abstract The present work concerns the modeling of the Payne effect in nonlinear viscoelasticity. This effect is a characteristic property of filled elastomers. Indeed, under cyclic loading of increasing amplitude, a decrease is shown in the storage modulus and a peak in the loss modulus. In this study, the Payne effect is assumed to arise from a change of the material microstructure, i.e., the thixotropy. The so-called intrinsic time or shift time was inferred from solving a differential equation that represents the evolution of a material's microstructure. Then, the physical time is replaced by the shift time in the framework of a recent fractional visco-hyperelastic model, which was linearized in the neighborhood of a static pre-deformation. As a result, we have investigated the effects of static pre-deformation, frequency, and magnitude of dynamic strain on storage and loss moduli in the steady state. Thereafter, the same set of parameters identified from the complex Young's modulus was used to predict the stress in the pre-deformed configuration. Finally, it is demonstrated that the proposed model is reasonably accurate in predicting Payne effect.

Damage-coupled ratcheting behaviors of SA508 Gr.3 steel at room and elevated temperatures: Experiments and simulations

2020 ◽  
Vol 29 (9) ◽  
pp. 1379-1396
Author(s):  
Jun Tian ◽  
Xiaolong Fu ◽  
Xuejiao Shao ◽  
Lu Jiang ◽  
Jian Li ◽  
...  
Keyword(s):  
Path Dependence ◽  
Elevated Temperatures ◽  
Kinematic Hardening ◽  
Cyclic Softening ◽  
Dynamic Strain ◽  
Loading Paths ◽  
Proposed Model ◽  
Series Of Experiments ◽  
Hardening Rules ◽  
Multiaxial Loadings

A series of experiments subjected to uniaxial and non-proportionally multiaxial cyclic loadings were performed to investigate the ratcheting responses of SA508 Gr.3 steel at room and elevated temperatures. The influences of different stress levels and nonproportional loading paths on the damage-coupled ratcheting responses were discussed. From experimental results, cyclic softening characteristic and dynamic strain aging can be observed under cyclic loadings. Moreover, the steel exhibits an obvious nonproportional path-dependence of the damage evolution under multiaxial loading paths. To numerically simulate the ratcheting responses under uniaxial and multiaxial loadings with the extended cyclic plastic model, the damage-coupled variable was introduced into the classic isotropic and nonlinear kinematic hardening rules. Corresponding material parameters could be calibrated from experimental data, and comparisons between experimental and simulated results were performed to validate the proposed model.

scholarly journals Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 403 ◽  
Author(s):  
Yongqiang Du ◽  
Jian Zheng ◽  
Guibo Yu
Keyword(s):  
Mechanical Properties ◽  
Aging Time ◽  
Loss Modulus ◽  
Accelerated Aging ◽  
Crosslinking Density ◽  
Dynamic Mechanical Properties ◽  
Maximum Elongation ◽  
Solid Rocket Motor ◽  
Payne Effect ◽  
Dynamic Mechanical

Hydroxyl terminated polybutadiene (HTPB) coating is widely used in a solid rocket motor, but an aging phenomenon exists during long-term storage, which causes irreversible damage to the performance of this HTPB coating. In order to study the effect of aging on the dynamic mechanical properties of the HTPB coating, the thermally-accelerated aging test was carried out. The variation of maximum elongation and crosslinking density with aging time was obtained, and a good linear relationship between maximum elongation and crosslinking density was found by correlation analysis. The changing regularity of dynamic mechanical properties with aging time was analyzed. It was found that with the increase of aging time, Tg of HTPB coating increased, Tα, tan β and tan α decreased, and the functional relationships between the loss factor parameters and crosslinking density were constructed. The storage modulus and loss modulus of HTPB coating increased with the increase of aging time, and decreased with the increase of pre-strain. The aging enhanced the Payne effect of HTPB coating, while the pre-strain had a weakening effect. In view of the Payne effect of HTPB coating, the crosslinking density was introduced into Kraus model as aging evaluation parameter, and the crosslinking density modified models with and without pre-strain were established. The proposed models can effectively solve the problem that the Kraus model has a poor fitting effect under the condition of small strain (generally less than 1%) and on the loss modulus, which have improved the correlations between the fitting results and the test results.

scholarly journals Dynamic Mechanical Analysis as a Complementary Technique for Stickiness Determination in Model Whey Protein Powders

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1295
Author(s):  
Laura O’Donoghue ◽  
Md. Haque ◽  
Sean Hogan ◽  
Fathima Laffir ◽  
James O’Mahony ◽  
...  
Keyword(s):  
Glass Transition ◽  
Dynamic Mechanical Analysis ◽  
Whey Protein ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Whey Protein Concentrate ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Lower Protein

The α-relaxation temperatures (Tα), derived from the storage and loss moduli using dynamic mechanical analysis (DMA), were compared to methods for stickiness and glass transition determination for a selection of model whey protein concentrate (WPC) powders with varying protein contents. Glass transition temperatures (Tg) were determined using differential scanning calorimetry (DSC), and stickiness behavior was characterized using a fluidization technique. For the lower protein powders (WPC 20 and 35), the mechanical Tα determined from the storage modulus of the DMA (Tα onset) were in good agreement with the fluidization results, whereas for higher protein powders (WPC 50 and 65), the fluidization results compared better to the loss modulus results of the DMA (Tα peak). This study demonstrates that DMA has the potential to be a useful technique to complement stickiness characterization of dairy powders by providing an increased understanding of the mechanisms of stickiness.

Modeling the Material Microstructure Effects on the Surface Generation Process in Microendmilling of Dual-Phase Materials

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
A. M. Abdelrahman Elkaseer ◽  
S. S. Dimov ◽  
K. B. Popov ◽  
M. Negm ◽  
R. Minev
Keyword(s):  
Chip Thickness ◽  
Machining Process ◽  
Surface Generation ◽  
Dual Phase ◽  
Generation Process ◽  
Phase Boundaries ◽  
Material Microstructure ◽  
Workpiece Material ◽  
Multiphase Materials ◽  
Proposed Model

The anisotropic behavior of the material microstructure when processing multiphase materials at microscale becomes an important factor that has to be considered throughout the machining process. This is especially the case when chip-loads and machined features are comparable in size to the cutting edge radius of the tool, and also similar in scale to the grain sizes of the phases present within the material microstructure. Therefore, there is a real need for reliable models, which can be used to simulate the surface generation process during microendmilling of multiphase materials.This paper presents a model to simulate the surface generation process during microendmilling of multiphase materials. The proposed model considers the effects of the following factors: the geometry of the cutting tool, the feed rate, and the workpiece material microstructure. Especially, variations of the minimum chip thickness at phase boundaries are considered by feeding maps of the material microstructure into the model. Thus, the model takes into account these variations that alter the machining mechanism from a proper cutting to ploughing and vice versa, and are the main cause of microburr formation. By applying the proposed model, it is possible to estimate more accurately the resulting roughness because the microburr formation dominates the surface generation process during microendmilling of multiphase materials. The proposed model was experimentally validated by machining two different samples of dual-phase steel under a range of chip-loads. The roughness of the resulting surfaces was measured and compared to the predictions of the proposed model under the same cutting conditions. The results show that the proposed model accurately predicts the roughness of the machined surfaces by taking into account the effects of material multiphase microstructure. Also, the developed model successfully elucidates the mechanism of microburr formation at the phase boundaries, and quantitatively describes its contributions to the resulting surface roughness after microendmilling.

Dynamic Mechanical Analysis of Fly Ash Filled Polyurea Elastomer

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Jing Qiao ◽  
Alireza V. Amirkhizi ◽  
Kristin Schaaf ◽  
Sia Nemat-Nasser
Keyword(s):  
Glass Transition ◽  
Fly Ash ◽  
Dynamic Mechanical Analysis ◽  
Volume Fraction ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Temperature Dependent ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Temperature Superposition

In this work, the material properties of a series of fly ash/polyurea composites were studied. Dynamic mechanical analysis was conducted to study the effect of the fly ash volume fraction on the composite’s mechanical properties, i.e., on the material’s frequency- and temperature-dependent storage and loss moduli. It was found that the storage and loss moduli of the composite both increase as the fly ash volume fraction is increased. The storage and loss moduli of the composites relative to those of pure polyurea initially increase significantly with temperature and then slightly decrease or stay flat, attaining peak values around the glass transition region. The glass transition temperature (measured as the temperature at the maximum value of the loss modulus) shifted toward higher temperatures as the fly ash volume fraction increased. Additionally, we present the storage and loss moduli master curves for these materials obtained through application of the time-temperature superposition on measurements taken at a series of temperatures.

Effect of Porosity on Dynamic Mechanical Properties of Rubber in Compression

1996 ◽  
Vol 69 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Alan I. Kasner ◽  
Eberhard A. Meinecke
Keyword(s):  
Dynamic Properties ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Static Loads ◽  
Filled Rubber ◽  
Storage And Loss Moduli ◽  
Nonlinear Stress ◽  
Stress Raisers ◽  
Different Levels ◽  
Cylindrical Samples

Abstract Cylindrical samples of different levels of porosity were prepared from a model carbon black filled rubber and tested in compression. Dynamic properties were determined with dynamic loads and dynamic displacements superimposed on static loads. Nonlinear stress-strain curves of porous rubber blocks produced a dependence of dynamic properties on the mode of testing. Both storage and loss moduli as well as tan γ were found to depend on the levels of porosity. The loss modulus was found to increase with higher strain levels in porous samples, while the storage modulus changed because of reduced sample stiffness. The dynamic data was in agreement with the results of Goodrich flexometer tests on porous and solid samples. The results suggest that the introduction of porosity reduces service life of rubber parts by providing stress raisers for crack initiation, rather than through changing the dynamic properties.

A lamination model for shape memory polymer/woven fabric composites

2019 ◽  
Vol 08 (02) ◽  
pp. 1950004
Author(s):  
Xiaobin Su ◽  
Xiongqi Peng
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Analysis And Design ◽  
Woven Fabric Composites ◽  
Proposed Model ◽  
Fabric Composites ◽  
Hyperelastic Model ◽  
Memory Cycle

Based on continuum mechanics and finite element method, a lamination model was developed for shape memory polymer composites (SMPCs) reinforced by woven fabrics. SMPCs were modeled as a laminated structure with woven fabric reinforcements embedded in shape memory polymers (SMPs). Thermo-responsive SMPs were defined by a 3D phenomenological model based on the phase transition approach, while woven fabric reinforcements were characterized by an anisotropic hyperelastic model. The proposed model was validated by comparing numerical results of a SMPC in the shape memory cycle of bending deformation with experimental data. Applications of the lamination model were demonstrated on numerical simulations of a tube made of SMPC in three shape memory cycles with different deformation modes. The proposed model is simple and applicable in the simulations of various shape memory cycles related to SMPCs. It also provides a theoretical foundation for the analysis and design optimization of woven fabric reinforced SMPC structures.

Thermal Viscoelastic Analysis of 3D Fabric Nanocomposites

2008 ◽  
Vol 47-50 ◽  
pp. 1133-1136 ◽  
Author(s):  
Nan Jia Zhou ◽  
Andrey Beyle ◽  
Christopher C. Ibeh
Keyword(s):  
Thermal Analysis ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Loss Tangent ◽  
Viscoelastic Properties ◽  
Vinyl Ester ◽  
Loss Modulus ◽  
Viscoelastic Analysis ◽  
Storage And Loss Moduli

Viscoelastic properties of 3D fabric reinforced Vinyl Ester composites were studied in different directions using Dynamic Mechanical Thermal Analysis (DMTA). Such materials filled by nanoparticles (silicon carbide) with different concentrations were also investigated. The increases of storage and loss moduli with addition of nanoparticles and with increase of their concentrations were observed. The maximal tangent of the angle of mechanical losses was especially compared at below and over glass transition temperature. Below glass transition temperature the presence of nanoparticles increases storage and loss moduli and loss tangent. These effects achieved maximum at glass transition temperature. Over glass transition, the loss modulus and loss tangent are decreased with increase of the concentration of nanoparticles.

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