Computational Simulation of Fracture Behavior Due to Mechanical and Constituent Properties of CFCCs

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1724-1729
Author(s):  
Oh Heon Kwon ◽  
Yu Seong Yun
Keyword(s):  
Numerical Simulation ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Computational Simulation ◽  
Matrix Material ◽  
Ceramic Matrix Composites ◽  
Matrix Cracking ◽  
Fiber Volume ◽  
Element Analysis ◽  
Cracking Stress

Continuous fiber reinforced ceramic matrix composites (CFCCs) are recently a subject of a lot of research interest due to advantages which are high specific stiffness and strength, high toughness and nonbrittle failure as compared to monolithic ceramics. The basic purpose of the present study is to describe graphically the fracture behavior of CFCCs according to a dependence on constituent properties. In CFCCs, following matrix cracking, intact fibers bridge effects impose closure tractions behind the crack tip that reduce the driving force for further cracking. Thus matrix cracking stress and bridging stress are important. Then the change of fiber volume fraction is given for the matrix cracking stress by the numerical simulation. Numerical simulation are carried out by using a finite element analysis code ANSYS. The double mesh concept is applied to account for fiber and matrix material properties.

Effective Property Estimation of CMC Minicomposites Considering Porosity

2018 ◽  
Author(s):  
Abhilash M. Nagaraja ◽  
Suhasini Gururaja
Keyword(s):  
Elastic Properties ◽  
Volume Fraction ◽  
Matrix Material ◽  
Ceramic Matrix Composites ◽  
Unit Cell ◽  
Matrix Cracking ◽  
Failure Behavior ◽  
Numerical Homogenization ◽  
Element Analysis ◽  
Micro Scale

Ceramic matrix composites (CMCs) are a promising subclass of composite materials suitable for high temperature applications. CMCs exhibit multiple damage mechanisms such as matrix cracking, interphase debonding, fiber sliding, fiber pullout, delaminations etc. Additionally, process induced defects such as matrix porosity exists at multiple length scales and has a considerable influence on the mechanical and failure behavior of CMCs. In the current work, the effect of intra-tow porosity, which exist at the micro-scale, on the mechanical behavior of CMCs has been investigated by numerical homogenization. Micro-scale response of 3 phase CMCs with intra tow pores has been obtained by finite element analysis based homogenization. Pores have been modeled as non-intersecting ellipsoids in a square unit cell representative of matrix material. The effective mechanical properties of porous matrix at the micro scale has been obtained from numerical homogenization, which are in good agreement with Mori-Tanaka mean field theory. The obtained matrix elastic properties have then been included in a three phase unit cell consisting of fiber, interphase and matrix representative of CMC microstructure. The effect of porosity volume fraction and aspect ratio on the effective elastic properties of the composite have been reported. Homogenization approach to model statistical distribution of pore size obtained from X-ray computed tomography of CMC minicomposite has been proposed.

Finite Element Analysis of Interfacial Debonding Damage in Fiber-Reinforced Ceramic Matrix Composites

2007 ◽  
Vol 546-549 ◽  
pp. 1555-1558
Author(s):  
Chun Jun Liu ◽  
Yue Zhang ◽  
Da Hai Zhang ◽  
Zhong Ping Li
Keyword(s):  
Finite Element ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Interfacial Debonding ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Element Analysis

In this paper the composite fracture process has been simulated via the finite element method. A micromechanics model was developed to predict the stress-strain response of a SiO2f/ SiO2 composite explicitly accounting for the local damage mechanisms such as fiber fracture and interfacial debonding. The effects of interfacial strength and fiber volume fraction on the toughness of fiber-reinforced ceramic matrix composites were investigated. The results showed that the composite failure behaviors correlated with the interface strength, which could achieve an optimum value for the elevation of the composite toughness. The increase of fiber volume fraction can make more toughening contributions.

Determination of fiber volume fraction in a cured laminate

2021 ◽  
pp. 002199832110112
Author(s):  
Qing Yang Steve Wu ◽  
Nan Zhang ◽  
Weng Heng Liew ◽  
Vincent Lim ◽  
Xiping Ni ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Evaluation Method ◽  
Volume Fraction ◽  
Matrix Material ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
Fiber Volume ◽  
Laser Ultrasonic ◽  
The Matrix

Propagation of ultrasonic wave in Carbon Fiber Reinforced Polymer (CFRP) is greatly influenced by the material’s matrix, resins and fiber volume ratio. Laser ultrasonic broadband spectral technique has been demonstrated for porosity and fiber volume ratio extraction on unidirection aligned CFRP laminates. Porosity in the matrix materials can be calculated by longitudinal wave attenuation and accurate fiber volume ratio can be derived by combined velocity through the high strength carbon fiber and the matrix material with further consideration of porosity effects. The results have been benchmarked by pulse-echo ultrasonic tests, gas pycnometer and thermal gravimetric analysis (TGA). The potentials and advantages of the laser ultrasonic technique as a non-destructive evaluation method for CFRP carbon fiber volume fraction evaluation were demonstrated.

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.

Influence of fiber volume fraction and curing temperature on mechanical properties of jute/PLA green composites

2019 ◽  
Vol 28 (4) ◽  
pp. 273-284
Author(s):  
Jai Inder Preet Singh ◽  
Sehijpal Singh ◽  
Vikas Dhawan
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Matrix Material ◽  
Research Work ◽  
Curing Temperature ◽  
Green Composites ◽  
Fiber Volume

Rising environmental concerns and depletion of petrochemical resources have resulted in an increased interest in biodegradable natural fiber-reinforced polymer composites. In this research work, jute fiber has been used as a reinforcement and polylactic acid (PLA) as the matrix material to develop jute/PLA green composites with the help of compression molding technique. The effect of fiber volume fraction ranging from 25% to 50% and curing temperature ranging from 160°C to 180°C on different samples were investigated for mechanical properties and water absorption. Results obtained from various tests indicate that with an increase in the fiber volume fraction, tensile and flexural strength increases till 30% fiber fraction, thereafter decreases with further increase in fiber content. Maximum tensile and flexural strength of jute/PLA composites was obtained with 30% fiber volume fraction at 160°C curing temperature. The trend obtained from mechanical properties is further justified through the study of surface morphology using scanning electron microscopy.

Fracture behavior of short-fiber reinforced materials

1992 ◽  
Vol 7 (11) ◽  
pp. 3120-3131 ◽  
Author(s):  
Michael Murat ◽  
Micha Anholt ◽  
H. Daniel Wagner
Keyword(s):  
Fracture Process ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Finite Size ◽  
Critical Length ◽  
Short Fiber ◽  
Fiber Volume ◽  
Linear Elastic ◽  
Fiber Reinforced Materials

A discrete model of springs with bond-bending forces is proposed to simulate the fracture process in a composite of short stiff fibers in a softer matrix. Both components are assumed to be linear elastic up to failure. We find that the critical fiber length of a single fiber composite increases roughly linearly with the ratio of the fiber elastic modulus to matrix modulus. The finite size of the lattice in the direction perpendicular to the fiber orientation considerably alters the behavior of the critical length for large values of the modulus ratio. The simulations of the fracture process reveal different fracture behavior as a function of the fiber content and length. We calculate the Young's modulus, fracture stress, and the strain at maximum stress as a function of the fiber volume fraction and aspect ratio. The results are compared with the predictions of other theoretical studies and experiments.

On the Actuation Authority of Adaptive Sandwich Beam with Composite Actuators: Coupled Finite Element Analysis

2012 ◽  
Vol 585 ◽  
pp. 332-336 ◽  
Author(s):  
K. Venkata Rao ◽  
S. Raja ◽  
T. Munikenche Gowda
Keyword(s):  
Numerical Experiments ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Element ◽  
Fiber Volume ◽  
Element Analysis ◽  
Active Fiber ◽  
Macro Fiber Composite

A two noded active sandwich beam element is formulated by employing layerwise Timoshenko’s beam theory. Displacement continuity conditions are imposed between different layers of the sandwich. This element is used to model an adaptive sandwich beam with macro-fiber composite (MFC) as extension actuator and shear actuated fiber composite (SAFC) as shear actuator. Influence of thickness and volume fraction of the active fiber (PZT-5A and single crystal PMN-PT) in the composite actuators on the actuation performance of the sandwich beam is investigated. Based on several numerical experiments, it is found that the PMN-PT based shear actuators give maximum actuation authority for the volume fraction of the fibers in the range of 80%-85%, whereas in case of PZT-5A based shear actuators the actuation authority remains maximum for the fiber volume fractions 80% and above.

Simulation of Low Velocity Impact Test on Carbon/Epoxy Composite Plates

2015 ◽  
Vol 1115 ◽  
pp. 523-526
Author(s):  
Ziamah B. Buang ◽  
S.M. Kashif
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Composite Plates ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact

Composite materials that have low weight and high strength properties are currently one of the promising materials for a vehicle’s body. However, the effect of low velocity impact on composite may cause failure through matrix cracking, fibre breakage and delamination which may reduce the structure strength. Low velocity impact can be analysed either by experimentation or numerical simulation. Numerical simulation which is also known as finite element analysis can show the degradation of the composite structure properties after an impact loading condition without doing any experimentation. Thus, in this paper, LS-DYNA is the finite element analysis software that is used to simulate a low velocity impact on composite structures.

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