Analysis of Interfacial Debonding in Three-Dimensional Composite Microstructures

2005 ◽  
Vol 128 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Shriram Swaminathan ◽  
N. J. Pagano ◽  
Somnath Ghosh
Keyword(s):  
Cohesive Zone ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Interfacial Debonding ◽  
Fiber Model ◽  
Unidirectional Fibers ◽  
Fiber Spacing ◽  
Commercial Code ◽  
Initiation And Propagation ◽  
The Matrix

This paper is aimed at analyzing stresses and fiber-matrix interfacial debonding in three-dimensional composite microstructures. It incorporates a 3D cohesive zone interface model based element to simulate interfacial debonding in the commercial code ABAQUS. The validated element is used to examine the potential debonding response in the presence of fiber–fiber interactions. A two-fiber model with unidirectional fibers is constructed and the effect of relative fiber spacing and volume fraction on the stress distribution in the matrix is studied. In addition, the effect of fiber orientation and spacing on the nature of initiation and propagation of interfacial debonding is studied in a two-fiber model. These results are expected to be helpful in formulating future studies treating optimal fiber orientations and payoff in controlling fiber spacing and alignment.

The effects of interfacial debonding on the elastoplastic response of unidirectional silicon carbide—titanium composites

2010 ◽  
Vol 224 (2) ◽  
pp. 259-269 ◽  
Author(s):  
M J Mahmoodi ◽  
M M Aghdam ◽  
M Shakeri
Keyword(s):  
Volume Fraction ◽  
Yield Criterion ◽  
Fibre Volume Fraction ◽  
Three Dimensional ◽  
Fibre Volume ◽  
Interfacial Debonding ◽  
Successive Approximation Method ◽  
Interface Damage ◽  
The Matrix ◽  
Von Mises

A three-dimensional micromechanics-based analytical model is presented to investigate the effects of initiation and propagation of interface damage on the elastoplastic behaviour of unidirectional SiC—Ti metal matrix composites (MMCs) subjected to off-axis loading. Temperature-dependent properties are considered for the matrix. Manufacturing process thermal residual stress (RS) is also included in the model. The selected representative volume element consists of r× c unit cells in which a quarter of the fibre is surrounded by matrix sub-cells. The constant compliance interface model is used to model interfacial debonding and the successive approximation method together with von Mises yield criterion is used to obtain elastoplastic behaviour. Dominance mode of damage including fibre fracture, interfacial debonding, and matrix yielding and ultimate tensile strength of the SiC—Ti MMC are predicted for various loading directions. The effects of thermal RS and fibre volume fraction on the stress—strain response of the SiC—Ti MMC are studied. Results revealed that for more realistic predictions, both interface damage and thermal RS effects should be considered in the analysis. The contribution of interfacial debonding and thermal RS in the overall behaviour of the material is also investigated. Comparison between results of the presented model shows very good agreement with the finite-element micromechanical analysis and experiment for various off-axis angles.

Comparison of Two Approaches to Model Cure-Induced Microcracking in Three-Dimensional Woven Composites

2012 ◽  
Author(s):  
Igor Tsukrov ◽  
Michael Giovinazzo ◽  
Kateryna Vyshenska ◽  
Harun Bayraktar ◽  
Jon Goering ◽  
...  
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Woven Composites ◽  
Finite Element Models ◽  
The Matrix ◽  
3D Woven Composites ◽  
The Difference ◽  
Resin Curing

Finite element models of 3D woven composites are developed to predict possible microcracking of the matrix during curing. A specific ply-to-ply weave architecture for carbon fiber reinforced epoxy is chosen as a benchmark case. Two approaches to defining the geometry of reinforcement are considered. One is based on the nominal description of composite, and the second involves fabric mechanics simulations. Finite element models utilizing these approaches are used to calculate the overall elastic properties of the composite, and predict residual stresses due to resin curing. It is shown that for the same volume fraction of reinforcement, the difference in the predicted overall in-plane stiffness is on the order of 10%. Numerical model utilizing the fabric mechanics simulations predicts lower level of residual stresses due to curing, as compared to nominal geometry models.

A Methodology for Synthesizing High-Performance Robots Fabricated With Optimally Tailored Composite Laminates

1987 ◽  
Vol 109 (1) ◽  
pp. 74-86 ◽  
Author(s):  
C. K. Sung ◽  
B. S. Thompson
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Robot Arms ◽  
The Matrix

An essential ingredient of the next generation of robotic manipulators will be high-strength lightweight arms which promise high-performance characteristics. Currently, a design methodology for optimally synthesizing these essential robotic components does not exist. Herein, an approach is developed for addressing this void in the technology-base by integrating state-of-the-art techniques in both the science of composite materials and also the science of flexible robotic systems. This approach is based on the proposition that optimal performance can be achieved by fabricating robot arms with optimal cross-sectional geometries fabricated with optimally tailored composite laminates. A methodology is developed herein which synthesizes the manufacturing specification for laminates which are specifically tailored for robotic applications in which both high-strength, high-stiffness robot arms are required which also possess high material damping. The parameters in the manufacturing specification include the fiber-volume fraction, the matrix properties, the fiber properties, the ply layups, the stacking sequence and the ply thicknesses. This capability is then integrated within a finite-element methodology for analyzing the dynamic response of flexible robots. An illustrative example demonstrates the approach by simulating the three-dimensional elastodynamic response of a robot subjected to a prescribed spatial maneuver.

An Interfacial Debonding Model for Particle-Reinforced Composites

2002 ◽  
Author(s):  
H. T. Liu ◽  
L. Z. Sun ◽  
J. W. Ju
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Damage Mechanism ◽  
Interfacial Debonding ◽  
Elastic Behavior ◽  
Reinforced Composites ◽  
Stiffness Tensor ◽  
Particle Reinforced Composites ◽  
Damage Process ◽  
Multi Phase

To simulate the evolution process of interfacial debonding between particle and matrix, and to further estimate its effect on the overall elastic behavior of particle-reinforced composites, a two-level microstructural-effective damaged model is developed. The microstructural damage mechanism is governed by the interfacial debonding of reinforcement and matrix. The progressive damage process is represented by the debonding angles that are dependent on the external loads. For those debonded particles, the elastic equivalency is constructed in terms of the stiffness tensor. Namely, the isotropic yet debonded particles are replaced by the orthotropic perfect particles. The volume fraction evolution of debonded particles is characterized by the Weibull’s statistical approach. Mori-Tanaka’s method is utilized to determine the effective stiffness tensor of the resultant multi-phase composites. The proposed constitutive framework is developed under the general three-dimensional loading condition. Examples are conducted to demonstrate the capability of the proposed model.

A generalized Archie’s law for n phases

Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. E247-E265 ◽  
Author(s):  
Paul W. J. Glover
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Reservoir Rock ◽  
Archie’S Law ◽  
Phase Volume Fraction ◽  
General Law ◽  
Special Cases ◽  
The Matrix ◽  
Definition Of

Archie’s law has been the standard method for relating the conductivity of a clean reservoir rock to its porosity and the conductivity of its pore fluid for more than [Formula: see text]. However, it is applicable only when the matrix is nonconducting. A modified version that allows a conductive matrix was published in 2000. A generalized form of Archie’s law is studied for any number of phases for which the classical Archie’s law and modified Archie’s law for two phases are special cases. The generalized Archie’s law contains a phase conductivity, a phase volume fraction, and phase exponent for each of its [Formula: see text] phases. The connectedness of each of the phases is considered, and the principle of conservation of connectedness in a three-dimensional multiphase mixture is introduced. It is confirmed that the general law is formally the same as the classical Archie’s law and modified Archie’s law for one and two conducting phases, respectively. The classical second Archie’s law is compared with the generalized law, which leads to the definition of a saturation exponent for each phase. This process has enabled the derivation of relationships between the phase exponents and saturation exponents for each phase. The relationship between percolation theory and the generalized model is also considered. The generalized law is examined in detail for two and three phases and semiquantitatively for four phases. Unfortunately, the law in its most general form is very difficult to prove experimentally. Instead, numerical modeling in three dimensions is carried out to demonstrate that it behaves well for a system consisting of four interacting conducting phases.

Extrinsic viscous anisotropy in two-phase aggregates, fabric parametrisation and application to mantle convection

2020 ◽  
Author(s):  
Albert de Montserrat Navarro ◽  
Manuele Faccenda
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Phase ◽  
Mantle Dynamics ◽  
Mineral Phases ◽  
Viscosity Contrast ◽  
The Matrix ◽  
Order Of Magnitude ◽  
Convection Patterns ◽  
Strong Inclusion

<p>Earth's mantle rocks are poly-aggregates where different mineral phases coexist.  These rocks may often be approximated as two-phase aggregates with a dominant phase and less abundant one (e.g. bridgmanite-ferropericlase aggregates in the lower mantle). Severe shearing of these rocks leads to a non-homogeneous partitioning of the strain between the different phases. The resulting bulk rock is mechanically not isotropic, and the elastic and the viscous tensor depend on the volume fraction and viscosity contrast between the mineral phases and the fabric.</p><p>Here we employ three-dimensional mechanical models to reproduce and parametrise fabrics typical of mantle rocks and quantify the evolution of the viscous tensor. These fabrics are produced by shearing a mechanically heterogeneous medium comprised by randomly distributed isotropic inclusions embedded in: i) a weak inclusion-strong matrix aggregate where strain is mainly accommodated by the weak phase, that flattens and yields a penetrative foliation; and, ii) a strong inclusion-weak matrix where strain is mainly accommodated by the matrix, in this case, the strong phase deforms primarily parallel to the direction of the flow, producing cigar-shaped inclusions.</p><p>Finally, we combine the fabric parametrisation of a two-phase aggregate with the Differential Effective Medium (DEM) theory to study the evolution of the viscous tensor and its effects in mantle dynamics. The results of two-dimensional models of thermal convection show that a viscosity contrast of one order of magnitude between the two mineral phases is enough to deflect mantle plumes and produce convection patterns that differ considerably from the ideal isotropic media.</p>

scholarly journals Micro-buckling of carbon fibers in shape memory polymer composites under bending in the glass transition temperature region

2021 ◽  
Vol 8 (1) ◽  
pp. 96-108
Author(s):  
Nilesh Tiwari ◽  
AbdulHafiz A. Shaikh
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Polymer Composites ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Minimum Energy ◽  
Three Dimensional ◽  
Fiber Volume ◽  
Half Wavelength ◽  
The Matrix

Abstract The influence of a wide temperature range in the glass transition region of a shape memory polymer (SMP) matrix on micro-buckling of the fiber reinforcements in shape memory polymer composites (SMPC) under large bending deformation is described. Analytical expressions to estimate the strain energy, neutral strain surface, critical buckling surface and half wavelength of the buckled fibers in the SMPC are presented based on the minimum energy method. This study considers the reinforced fibers as three-dimensional elastic bodies and the matrix as a temperature stimulated flat plate. A comprehensive study was performed to understand the dynamic temperature behavior of the micro-buckled fibers and corresponding results were validated by previous works in the literature. The effects of fiber volume fraction and thickness of the SMPC plates on the half wavelength are also discussed along with the simultaneous influence of temperature on the parameters computed in the minimum energy analysis.

Average Strain in Fiber Bundles and Its Effect on NCF Composite Stiffness

2006 ◽  
Vol 129 (2) ◽  
pp. 211-219 ◽  
Author(s):  
H. David Mattsson ◽  
Janis Varna
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Effective Stiffness ◽  
Main Element ◽  
Transverse Strain ◽  
Fe Model ◽  
Strain Component ◽  
Average Strain ◽  
The Matrix ◽  
Homogenization Methods

Transverse strain in bundles governs transverse cracking in noncrimp fabric (NCF) composites. Finite element (FE) analysis shows that this strain may be significantly lower than the applied macroscopic strain component in the same direction. This feature is important for damage evolution modeling. The isostrain assumption which in different combinations is widely used in stiffness models is inadequate because the strain in different mesoelements (bundles of different orientation and matrix regions) is assumed the same. Analyzing by FEM the importance of media surrounding the bundle on average transverse strain it was found that an increasing ratio of the bundle transverse stiffness to the matrix stiffness leads to a decrease of the strain in the bundle. An increase of the stiffness in the same direction in adjacent layers leads to an increase of the transverse strain in the bundle. Higher bundle volume fraction in the layer leads to larger transverse strain in the bundle. These trends are described by a power law and used to predict the average strain in bundles. The calculated H matrix which establishes the relationship between strains in the mesoelement and representative volume element strains is used to calculate the “effective stiffness” of the bundle. This effective stiffness is the main element in simple but exact expressions derived to calculate the stiffness matrix of NCF composites. Considering the three-dimensional (3D) FE model as the reference, it was found that all homogenization methods used in this study have sufficient accuracy for stiffness calculations, but only the presented method gives reliable predictions of strains in bundles.

Three-dimensional orthogonal nonwoven single polymer composite

2017 ◽  
Vol 36 (12) ◽  
pp. 889-899
Author(s):  
Ning Wu ◽  
Shanshan Zheng ◽  
Jie Yang ◽  
Yang Gao ◽  
Jing Wang ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Volume Fraction ◽  
Density Ratio ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Bending Properties ◽  
Fiber Volume ◽  
The Matrix ◽  
Mechanical Bending ◽  
Consolidation Temperature

This paper describes the production and bending properties of three-dimensional orthogonal single polymer composites made from axial–braider commingling yarns where the braider yarns are completely melted to produce the matrix phase. The research was demonstrated using poly(lactic acid) yarn as an example. The optimum linear density ratio of braider and axial yarn was prescreened. The effects of consolidation temperature, pressure, and preform thickness on the bending properties were investigated by Environment Scanning Electron Microscope (ESEM) observations and mechanical bending tests. The results showed that the best bending properties of single poly(lactic acid) composite were detected in the braider–axial yarns ratio of 5/6. At this ratio, the increase of the consolidation temperature was to improve the bending properties (from 145 to 160℃), while it markedly decreased at 165℃. As the processing pressure increased, a remarkable improvement in the interfacial bonding between fibers and matrix occurred at a pressure of around 8 MPa. The increase of preform thickness gave rise to higher fiber volume fraction in the single poly(lactic acid) composite, with the result that the peak values of maximum stress and modulus were obtained at the preform thickness of 9 mm.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

Sign in / Sign up

Export Citation Format

Share Document