Damage evolution in fibrous composites caused by interfacial debonding

2019 ◽  
Vol 29 (1) ◽  
pp. 67-85 ◽  
Author(s):  
Yizhan Yang ◽  
Jiankang Chen ◽  
Zhuping Huang
Keyword(s):  
Damage Evolution ◽  
Loading Condition ◽  
Statistical Approach ◽  
Energy Criterion ◽  
Interfacial Debonding ◽  
Fibrous Composites ◽  
Dispersion Degree ◽  
The Matrix ◽  
Adhesive Energy ◽  
Damage Types

Interfacial debonding between fibers and matrix is one of the dominant damage types in fibrous composites. This paper investigates weakening effect due to the interfacial debonding. For simplification, the fibers are assumed to be rigid since the modulii and strength of fibers are much greater than those of matrix, and the distribution of the radii of fibers is assumed to obey the logarithmic normal distribution. The matrix is assumed to be a viscoelastic material. The boundary of the composite is subjected to transverse loading condition, the direction of which is perpendicular to that of fibers. The interfacial debonding between fibers and matrix is analyzed by the energy criterion, and the evolution formula of nucleated porosity due to the debonding is derived by the statistical approach. A newly defined volume average method is proposed to establish the macroscopic constitutive relation of the composites. The effect of the material parameters of matrix, as well as the size of fibers on the critical stress for the interfacial debonding and damage evolution are discussed in detail. The results obtained in this paper indicate that the macroscopic strain rate, the dispersion degree of the fiber's radii, the adhesive energy at the interface, and loading condition play key roles in the overall mechanical properties of the composites.

scholarly journals Exploring the Capability of HAADF-STEM Techniques to Characterize Graphene Distribution in Nanocomposites by Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
N. Baladés ◽  
D. L. Sales ◽  
M. Herrera ◽  
A. M. Raya ◽  
J. C. Hernández-Garrido ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Carbon Matrix ◽  
Reconstruction Algorithm ◽  
Dark Field ◽  
Graphene Layers ◽  
Transmission Electron ◽  
Dispersion Degree ◽  
Scanning Transmission ◽  
The Matrix ◽  
Annular Dark Field

This paper explores the capability of scanning transmission electron microscopy (STEM) techniques in determining the dispersion degree of graphene layers within the carbon matrix by using simulated high-angle annular dark-field (HAADF) images. Results ensure that unmarked graphene layers are only detectable if their orientation is parallel to the microscope beam. Additionally, gold-marked graphene layers allow evaluating the dispersion degree in structural composites. Moreover, electron tomography has been demonstrated to provide truthfully 3D distribution of the graphene sheets inside the matrix when an appropriate reconstruction algorithm and 2D projections including channelling effect are used.

Fatigue Failures of Differences Behaviour on CSM/Woven Roving Composite Materials

2013 ◽  
Vol 471 ◽  
pp. 335-340 ◽  
Author(s):  
A.M.T. Arifin ◽  
S. Abdullah ◽  
Rozli Zulkifli ◽  
D.A. Wahab
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Composite Structure ◽  
Loading Condition ◽  
Fatigue Loading ◽  
The Matrix ◽  
Chopped Strand Mat ◽  
Materials Used ◽  
Tension Loading ◽  
Fatigue Failures

This paper presents the investigation of composite materials lamination using different materials in the structure of lamination. The main purpose of the study is to evaluate the behaviour of characteristics in composite materials subjected to difference of fatigue loading, leading to understand the criteria that influence the behaviour of composite lamination structure. Therefore, in this research, the orientation of lamination structure used is 00/900and the material selected for the study were chopped strand mat (csm) and woven roving fabric (wr) as a reinforcement and the matrix used were polyester and epoxy resin. The composite lamination structure was produced using hand lay-up technique. The fatigue condition experiment of composite materials in this research was carried under tension-tension loading. With difference in fatigue loading condition, the lifetime of composite structure will be different and the cracking phenomenon in the structure will also be different. It is suggested that, different number of lamination and amount of reinforcement and matrix, produce a variety of materials characteristic with respect to elasticity of material. An implication of the study in this research showed various behaviour of composite materials with different materials used and it showed a difference phenomenon in comparison to metalic materials.

Bending Damage Evolution and Its Influence on Critical Current and N-Value of Bi2223/Ag Superconducting Composite Tape

2005 ◽  
Vol 475-479 ◽  
pp. 933-936
Author(s):  
D. Doko ◽  
N. Miyazaki ◽  
Shojiro Ochiai ◽  
Hiroshi Okuda ◽  
Sang Soo Oh ◽  
...  
Keyword(s):  
Critical Current ◽  
Damage Evolution ◽  
Interfacial Debonding ◽  
The Other ◽  
N Value ◽  
Composite Tape ◽  
Bending Behavior ◽  
Superconducting Current

Bending behavior of Bi2223/Ag superconducting composite tapes, and the influence of the bending damages on critical superconducting current Ic and n-value that is a measure for the sharpness of the transition from super- to normal conduction, were studied. Following damages, responsible to the reduction in critical current at high bending strains, were observed. (i) Transverse and (ii) longitudinal crackings of the filaments, (iii) interfacial debonding between filaments and silver, and (iv) buckling in compression side. The damage of the filaments arose first locally, resulting in a reduction of the Ic and n-value in the corresponding local portion. The overall Ic and n-values were determined by such a local portion. With increasing strain, the damage of the other portions arose successively, resulting in loss of superconductivity in all portions.

A Study on Characteristic of Polymer Matrix Composites Using Experimental and Statistical Approach

2013 ◽  
Vol 368-370 ◽  
pp. 683-686
Author(s):  
Ahmad Mubarak Tajul Arifin ◽  
Shahrum Abdullah ◽  
Rozli Zulkifli ◽  
Dzuraidah Abd Wahab
Keyword(s):  
Polymer Matrix ◽  
Statistical Approach ◽  
Polymer Matrix Composites ◽  
Stacking Sequence ◽  
Matrix Composites ◽  
The Matrix ◽  
Thermoset Epoxy ◽  
Chopped Strand Mat ◽  
Materials Used ◽  
And Behavior

This paper focuses on the characteristic study of polymer matrix composites using a statistical approach, in terms of difference experimental and reflected to difference stacking sequence and orientation of composite lamination. Composite material, have an excellent characteristic and behavior, but with a difference application and materials used, it have a difference phenomenon occurred before the composite structure are collapsed. Therefore, in order to understand the characteristic of polymer matrix composites, it needs to investigate the phenomenon that influences the structure of composite lamination before failures. In this research, polymer matrix composites are produced using difference material and stacking sequence of lamination. The matrix used is thermoset epoxy and polyester resin with chopped strand mat (CSM) and woven roving (WR) as reinforcement materials. It has been produced using hand lay-up technique. The experimental work is carried out using the tension and flexural test accordance to ASTM-D3039 and D-D790 standard. By using a statistical approach, it can clearly show the differential between materials used with a characteristic of composite materials. It is noted, based on this investigation it also showed difference phenomenon failures and damage structure of polymer matrix composites with difference type of experimental.

Unresolved Issues With Regard to Creep and Creep Fatigue Life Prediction

2002 ◽  
Author(s):  
J. Oh ◽  
N. Katsube ◽  
F. W. Brust
Keyword(s):  
Cyclic Loading ◽  
Damage Evolution ◽  
Life Prediction ◽  
Loading Condition ◽  
Cyclic Strain ◽  
Rupture Process ◽  
Steady State Creep ◽  
Creep Failure ◽  
Cyclic Loading Condition ◽  
Creep Fatigue

This paper studies intergranular creep failure of high temperature service material under a stress-controlled unbalanced cyclic loading condition. The grain boundary rupture process was numerically analyzed using Tvergaard’s axisymetric model. The present numerical model incorporated the experimentally verified Murakami-Ohno cyclic strain hardening creep law and Norton’s creep law. The numerical results show that void growth accelerates under cyclic loading condition. Also, analysis shows that a steady state creep law is not sufficient to analyze damage evolution under cyclic loading conditions.

The Effect of the Property of Non-Linear Viscosity on the Interfacial Debonding of Particulate-Reinforced Polymers

2006 ◽  
Vol 324-325 ◽  
pp. 113-116
Author(s):  
Jian Kang Chen ◽  
Liu Hong Chang
Keyword(s):  
Matrix Material ◽  
Energy Criterion ◽  
Interfacial Debonding ◽  
Reinforced Polymers ◽  
Viscoelastic Matrix ◽  
Non Linear Equation ◽  
Linear Viscoelastic Material ◽  
Non Linear ◽  
Linear Viscoelastic ◽  
Particulate Reinforced

The debonding of a rigid particle embedded in an infinite non-linear viscoelastic material is investigated in this paper. Under sphere-symmetric deformation, a non-linear equilibrium equation expressed by velocity of a particle in the viscoelastic matrix material is derived. The strain rate is obtained by solving non-linear equation in terms of iterative method. According to the energy criterion, the critical instant of the interfacial debongding is calculated. Numerical results show that the influence of non-linear viscosity on the interfacial debonding is significant.

scholarly journals An Upper Bound of Longitudinal Elastic Modulus for Unidirectional Fibrous Composites as Obtained from Strength of Materials Approach

2018 ◽  
Author(s):  
John Venetis ◽  
Emilio Sideridis
Keyword(s):  
Elastic Modulus ◽  
Upper Bound ◽  
Theoretical Models ◽  
The Novel ◽  
Fibrous Composites ◽  
Strength Of Materials ◽  
Fiber Concentration ◽  
Longitudinal Elastic Modulus ◽  
The Matrix ◽  
Specific Variation

In this paper, an upper bound of the longitudinal elastic modulus of  unidirectional   fibrous composites is proposed according to strength of materials approach, on the premise that the fiber is much stiffer than the matrix. In the mathematical derivations, the concept of boundary interphase between fiber and matrix was also taken into account and the main objective of this work is the attainment of an upper bound for the interphase stiffness with respect to fiber concentration by volume. The novel element here is that the authors have not taken into consideration any specific variation law to approximate the interphase modulus. The theoretical results arising from the proposed formula were compared with those obtained from some reliable theoretical models as well as with experimental data found in the literature, and a satisfactory agreement was observed.

scholarly journals Morphology and Rheology of Nanofilled PP / PVA Blends

2017 ◽  
Vol 54 (4) ◽  
pp. 735-739 ◽  
Author(s):  
Natalia Rezanova ◽  
Yurii Budash ◽  
Viktoriia Plavan ◽  
Olena Ishchenko ◽  
Viktoriia Bulakh
Keyword(s):  
Sodium Oleate ◽  
Effective Viscosity ◽  
Formation Processes ◽  
Ternary Blends ◽  
Longitudinal Deformation ◽  
Dispersion Degree ◽  
Phase Type ◽  
The Matrix ◽  
Mixing Method ◽  
Nanoparticle Additives

The influence of Ag/SiO2 as nanofiller and sodium oleate as compatibilizer and their mixtures on the patterns flow and structure formation processes in thermodynamically incompatible polypropylene/plasticized polyvinylalcohol (PP / PVA) systems were studied. It is found that the change in the sequence of mixing the ingredients of the composition allows adjusting the morphology phase type due to the predominant localization of nanoparticle additives in the melt amount of a component or on the border of phase separation. Injection of Ag/SiO2 to melt PP increases dispersion degree and homogeneity of its distribution in the matrix. Simultaneous use of nanoadditive and sodium oleate as compatibilizer improves the connections between the polymers and promotes thinner and more homogeneous dispersion of the particles of the dispersed phase. It is shown that the effective viscosity of melt nanofilled system is determined by components mixing method: viscosity of melt blend increases when the additive is localized predominantly in the PVA and decreases with the prior injection of PP. The nature of the flow for all researched compositions obeys a power law and almost does not depend on the method of mixing. The ability of the longitudinal deformation of ternary blends is deteriorating, but remains sufficient for their processing. Combining nanoadditive with compatibilizer promotes increased elasticity and the melt spinnability of modified blends.

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