Toughening Mechanism and Mechanical Properties Simulation of Rubber-Toughened Polymers

2016 ◽  
Vol 723 ◽  
pp. 68-73
Author(s):  
Hong Tu Song
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Rubber Particle ◽  
Particle Volume Fraction ◽  
Poisson's Ratio ◽  
Toughening Mechanism ◽  
Particle Volume ◽  
Rubber Toughened

When blending rubbers into polymers, different rubber distribution status and fraction due to different mechanical property. In this research, effective mechanical properties of rubber-toughened polymers with four blending fraction in six kinds of particle distribution status are simulated numerically by using finite element method. Rubber particle distribution model include four 2D models and two 3D models. Typical effective mechanical properties such as yield stress, Young's modulus, Poisson's ratio and stress-strain curve of each status are obtained. The Results show that all models Young's modulus and Poisson's ratio decrease with rubber particle volume fraction increasing. Young's modulus and Poisson's ratio of three-dimensional body-centered cubic and face-centered cubic models are in a close magnitude range, it means rubber particle volume fraction has less effect on 2D models and two 3D models. As we all known, Matrix yielding, crazing and interface debond. All play an important role in the toughening process of rubber-toughened polymers. So in this paper we also study on toughening mechanism using same models. Our simulation takes use of stress concentration factor, yield ratio and interface elements' strain difference which is related with matrix yielding, crazing and interface debond to study the toughening mechanism. Simulation shows that the maximum stress concentration factor increases with particle volume fraction. The shear yielding occurs first at the equator of rubber particle, and then yield region expands from the equator to the pole of the particle with loads increasing.

Probabilistic Modeling for Composites with Particle Interface Degrading

2007 ◽  
Vol 280-283 ◽  
pp. 1827-1832
Author(s):  
Hua Jian Chang ◽  
Yu Zhou ◽  
Michihiko Nakagaki
Keyword(s):  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Constitutive Law ◽  
Poisson's Ratio ◽  
Damage Effect ◽  
Elastic State ◽  
Particle Volume ◽  
Inclusion Type ◽  
Material Interface

A popular type is of metal matrix reinforced by ceramics particles. It has been revealed that the composites are susceptible to interfacial degrading, which may be dramatically detrimental to the overall properties of composites. In present paper, an equivalent inclusion type constitutive model was developed for the composites with dispersed particles on which imperfections of the material interface are incurred. Two fundamental tensors are derived, the modified Eshelby tensor and the damage tensor of the weakened particles. By applying these tensors into a carefully schemed constitutive law, the effects of interfacial degrading on the overall properties of composite materials can be investigated. The interface degrading includes sliding and debonding. The numerical results show that even with the nil resistible sliding coefficient, its effect on the overall Young’s modulus is not notable unless the volume fraction of the particle is so high as more than 70%. For the global Poisson’s ratio, when there is the sliding on the interface, the Poisson’s ration rises irrespective of the constituent material values. It is noted that even in the elastic state, the global Poisson’s ratio rises greater than that of both the constituents. This phenomenon might indicate that even at the elastic state, the particle interfacial sliding would give somewhat a plasticity-like deformation behavior. The effect of the interfacial debonding on the overall properties of the composite is more conspicuous in comparisons of the sliding. The debonding parameter greatly affects both the properties for almost entire range of the particle volume fraction. Unlike the sliding effect case, the debonding decreases Poisson’s ratio at all cases, which represents the micro-damage effect occurring in the composite.

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Biomimetic composites inspired by venous leaf

2017 ◽  
Vol 52 (3) ◽  
pp. 361-372 ◽  
Author(s):  
Gongdai Liu ◽  
R Ghosh ◽  
A Vaziri ◽  
A Hossieni ◽  
D Mousanezhad ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Stress ◽  
Poisson’S Ratio ◽  
Composite Structures ◽  
Volume Fraction ◽  
Matrix Material ◽  
Poisson's Ratio ◽  
Fiber Volume ◽  
Young’S Moduli

A typical plant leaf can be idealized as a composite having three principal fibers: the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary fibers embedded in a matrix material. This paper introduces a biomimetic composite design inspired by the morphology of venous leafs and investigates the effects of venation morphologies on the in-plane mechanical properties of the biomimetic composites using finite element method. The mechanical properties such as Young’s moduli, Poisson’s ratio, and yield stress under uniaxial loading of the resultant composite structures was studied and the effect of different fiber architectures on these properties was investigated. To this end, two broad types of architectures were used both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions were kept constant and a comparative parametric study was carried out by varying the inclination of the secondary fibers. The results show that the elastic modulus of composite in the direction of main fiber increases linearly with increasing the angle of the secondary fibers. Furthermore, the elastic modulus is enhanced if the secondary fibers are closed, which mimics composites with closed cellular fibers. In contrast, the elastic modulus of composites normal to the main fiber ( x direction) exponentially decreases with the increase of the angle of the secondary fibers and it is little affected by having secondary fibers closed. Similar results were obtained for the yield stress of the composites. The results also indicate that Poisson’s ratio linearly increases with the secondary fiber angle. The results also show that for a constant fiber volume fraction, addition of various tertiary fibers may not significantly enhance the mechanical properties of the composites. The mechanical properties of the composites are mainly dominated by the secondary fibers. Finally, a simple model was proposed to predict these behaviors.

Young's Modulus and Poisson's Ratio Estimation Based on PSO Constriction Factor Method Parameters Evaluation

2019 ◽  
Vol 9 (2) ◽  
pp. 33-46
Author(s):  
George Lucas Dias ◽  
Ricardo Rodrigues Magalhães ◽  
Danton Diego Ferreira ◽  
Bruno Henrique Groenner Barbosa
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Young’S Modulus ◽  
Cantilever Beam ◽  
Poisson’S Ratio ◽  
Inverse Analysis ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Factor Method ◽  
Constriction Factor

The knowledge of materials' mechanical properties in design during product development phases is necessary to identify components and assembly problems. These are problems such as mechanical stresses and deformations which normally cause plastic deformation, early fatigue or even fracture. This article is aimed to use particle swarm optimization (PSO) and finite element inverse analysis to determine Young's Modulus and Poisson's ratio from a cantilever beam, manufactured in ASTM A36 steel, subjected to a load of 19.6 N applied to its free end. The cantilever beam was modeled and simulated using a commercial FEA software. Constriction Factor Method (PSO variation) was used and its parameters were analyzed in order to improve errors. PSO results indicated Young's Modulus and Poisson's ratio errors of around 1.9% and 0.4%, respectively, when compared to the original material properties. Improvement in the data convergence and a reduction in the number of PSO iterations was observed. This shows the potentiality of using PSO along with Finite Element Inverse Analysis for mechanical properties evaluation.

Design Optimization of Material Properties in a Particle-Filled Composite Material System

2008 ◽  
Author(s):  
Siva P. Gurrum ◽  
Jie-Hua Zhao ◽  
Darvin R. Edwards
Keyword(s):  
Composite Material ◽  
Young’S Modulus ◽  
Material Properties ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Filler Content ◽  
Young's Modulus ◽  
Random Packing ◽  
Poisson's Ratio ◽  
Analytical Models

This work presents a methodology implementing random packing of spheres combined with commercial finite element method (FEM) software to optimize the material properties, such as Young’s modulus, Poisson’s ratio, coefficient of thermal expansion (CTE) of two-phase materials used in electronic packaging. The methodology includes an implementation of a numerical algorithm of random packing of spheres and a technique for creating conformal FEM mesh of a large aggregate of particles embedded in a medium. We explored the random packing of spheres with different diameters using particle generation algorithms coded in MATLAB. The FEM meshes were generated using MATLAB and TETGEN. After importing the nodes and elements databases into commercial FEM software ANSYS, the composite materials with spherical fillers and the polymer matrix were modeled using ANSYS. The effective Young’s modulus, Poisson’s ratio, and CTE along different axes were calculated using ANSYS by applying proper loading and boundary conditions. It was found that the composite material was virtually isotropic. The Young’s modulus and Poisson’s ratio calculated by FEM models were compared to a number of analytical solutions in the literature. For low volume fraction of filler content, the FEM results and analytical solutions agree well. However, for high volume fraction of filler content, there is some discrepancy between FEM and analytical models and also among the analytical models themselves.

Mechanical Properties of Biomimetic Leaf Composite

2016 ◽  
Author(s):  
Hamid Nayeb Hashemi ◽  
Gongdai Liu ◽  
Ashkan Vaziri ◽  
Masoud Olia ◽  
Ranajay Ghosh
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
Poisson’S Ratio ◽  
Composite Structures ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Poisson's Ratio ◽  
Closed Cell ◽  
Cell Architecture ◽  
The Matrix

In this paper, we mimic the venous morphology of a typical plant leaf into a fiber composite structure where the veins are replaced by stiff fibers and the rest of the leaf is idealized as an elastic perfectly plastic polymeric matrix. The variegated venations found in nature are idealized into three principal fibers — the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element (FE) based computational investigation of the mechanical properties such as Young’s moduli, Poisson’s ratio and yield stress under uniaxial loading of the resultant composite structures and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find significant effect of fiber inclination on the overall mechanical properties of the composites with higher fiber angles transitioning the composite increasingly into a matrix-dominated response. We also find that in general, composites with only secondary fibers are stiffer with closed cell architecture of the secondary fibers. The closed cell architecture also arrested the yield stress decrease and Poisson’s ratio increase at higher fiber angles thereby mitigating the transition into the matrix dominated mode. The addition of tertiary fibers also had a pronounced effect in arresting this transition into the matrix dominated mode. However, it was found that indiscriminate addition of tertiary fibers may not provide desired additional stiffness for fixed volume fraction of constituents. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.

XRD Tensile Test Technique to Measure Mechanical Properties of Micron-Thick Si and TiN Films

2005 ◽  
Vol 297-300 ◽  
pp. 574-580 ◽  
Author(s):  
Takahiro Namazu ◽  
Shozo Inoue ◽  
Daisuke Ano ◽  
Keiji Koterazawa
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Partial Pressure ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Lateral Strain ◽  
Test Technique ◽  
Tin Films

This paper focuses on investigating mechanical properties of micron-thick polycrystalline titanium nitride (TiN) films. We propose a new technique that can directly measure lateral strain of microscale crystalline specimen by X-ray diffraction (XRD) during tensile test. The XRD tensile test can provide not only Young’s modulus but also Poisson’s ratio of TiN films. Micron-thick TiN films were deposited onto both surfaces of single crystal silicon (Si) specimen by r.f. reactive magnetron sputtering. Young’s modulus and Poisson’s ratio of Si specimen obtained by XRD tensile tests were in good agreement with analytical values. TiN films deposited at Ar partial pressure of 0.7Pa had the average values of 290GPa and 0.36 for Young’s modulus and Poisson’s ratio. The elastic mechanical properties of TiN films gradually decreased down to 220GPa and 0.29 with increasing Ar partial pressure up to 1.0Pa, regardless of film thickness. The change in the film properties with Ar partial pressure would be attributed to the change in the film density.

Microstructure and mechanical properties of AlCrFeCoNi high-entropy alloy particle reinforced Mg-9Al-1Zn matrix composites

2021 ◽  
Vol 112 (7) ◽  
pp. 538-545
Author(s):  
Yongsheng Chen ◽  
Zesheng Ji ◽  
Maoliang Hu ◽  
Hongyu Xu ◽  
Guangjie Feng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Volume Fraction ◽  
Dominant Role ◽  
Particle Volume Fraction ◽  
Stress Transfer ◽  
High Entropy Alloy ◽  
Compression Tests ◽  
Particle Volume ◽  
High Entropy

Abstract AlCrFeCoNi particles were added to Mg-9Al-1Zn alloy in a rotary blowing process. The microstructures and mechanical properties of Mg-9Al-1Zn based composites were characterized by means of X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and tensile and compression tests at room temperature. Results revealed that AlCrFeCoNi particles could effectively refine the grains, and the rotary blowing process enabled the uniform distribution of these particles. The mechanical properties of composites improved with the increase of particle volume fraction. The superior wettability of AlCrFeCoNi particles supported their reliable bonding with the Mg-9Al-1Zn matrix. The Hall–Petch strengthening and stress transfer effect played a dominant role in the improvement of compressive and tensile properties.

Stiffness Prediction of Nano-Fibers Composite Ceramics

2007 ◽  
Vol 121-123 ◽  
pp. 1171-1174 ◽  
Author(s):  
Jian Zheng ◽  
Xin Hua Ni ◽  
Zhan Jun Yao
Keyword(s):  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Eutectic Structure ◽  
Poisson's Ratio ◽  
Composite Ceramics ◽  
Random Orientation ◽  
Average Value ◽  
Volume Average

Nano-fibers composite ceramics were mainly composed of fiber eutectics with random orientation, in which nanometer sized second fibers are dispersed within the ceramic matrix. First, Mori-Tanaka method was used to predict the stiffness of the fiber eutectic structure. The fiber eutectic structure is transverse isotropy and has five independent elastic constants. Then considering random orientation of the fiber eutectic structure, the Young’s modulus and Poisson’s ratio of composite ceramics is determined by mean strain. Composite ceramics is isotropy. When the volume fraction of nano-fibers increase, the Young’s modulus of composite ceramics decrease and are little smaller than the volume average value, the Poisson’s ratio of composite ceramics decrease and are little bigger than the volume average value.

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