scholarly journals Mechanical Behavior of Fiber-Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment

1993 ◽  
Vol 115 (1) ◽  
pp. 91-102 ◽  
Author(s):  
A. Chulya ◽  
J. P. Gyekenyesi ◽  
R. T. Bhatt
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Matrix Composites ◽  
In Situ Monitoring ◽  
Matrix Cracking ◽  
Test Problems ◽  
Interface Debonding ◽  
Failure Behavior ◽  
Fiber Reinforced ◽  
History Effects ◽  
Pull Out

The mechanical behavior of continuous fiber-reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytic predictions.

scholarly journals Mechanical Behavior of Fiber Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment

1991 ◽  
Author(s):  
Abhisak Chulya ◽  
John P. Gyekenyesi ◽  
Ramakrishna T. Bhatt
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Matrix Composites ◽  
In Situ Monitoring ◽  
Matrix Cracking ◽  
Test Problems ◽  
Interface Debonding ◽  
Failure Behavior ◽  
Fiber Reinforced ◽  
History Effects ◽  
Pull Out

The mechanical behavior of continuous fiber reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytical predictions.

Effect of temperature on matrix multicracking evolution of C/SiC fiber-reinforced ceramic-matrix composites

2020 ◽  
Vol 39 (1) ◽  
pp. 189-199
Author(s):  
Longbiao Li
Keyword(s):  
Strain Energy ◽  
Ceramic Matrix Composites ◽  
Critical Value ◽  
Matrix Cracking ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Temperature Dependent ◽  
Damage State ◽  
The Matrix ◽  
Sic Composites

AbstractIn this paper, the temperature-dependent matrix multicracking evolution of carbon-fiber-reinforced silicon carbide ceramic-matrix composites (C/SiC CMCs) is investigated. The temperature-dependent composite microstress field is obtained by combining the shear-lag model and temperature-dependent material properties and damage models. The critical matrix strain energy criterion assumes that the strain energy in the matrix has a critical value. With increasing applied stress, when the matrix strain energy is higher than the critical value, more matrix cracks and interface debonding occur to dissipate the additional energy. Based on the composite damage state, the temperature-dependent matrix strain energy and its critical value are obtained. The relationships among applied stress, matrix cracking state, interface damage state, and environmental temperature are established. The effects of interfacial properties, material properties, and environmental temperature on temperature-dependent matrix multiple fracture evolution of C/SiC composites are analyzed. The experimental evolution of matrix multiple fracture and fraction of the interface debonding of C/SiC composites at elevated temperatures are predicted. When the interface shear stress increases, the debonding resistance at the interface increases, leading to the decrease of the debonding fraction at the interface, and the stress transfer capacity between the fiber and the matrix increases, leading to the higher first matrix cracking stress, saturation matrix cracking stress, and saturation matrix cracking density.

NDE Characterization and Mechanical Behavior in Ceramic Matrix Composites

2006 ◽  
Vol 321-323 ◽  
pp. 946-951 ◽  
Author(s):  
Jeong Guk Kim ◽  
Sung Tae Kwon ◽  
Won Kyung Kim
Keyword(s):  
Mechanical Behavior ◽  
Nondestructive Evaluation ◽  
Tensile Testing ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
In Situ Monitoring ◽  
Matrix Composites ◽  
Ir Camera ◽  
Qualitative Relationship ◽  
Microscopy Characterization

Several nondestructive evaluation (NDE) techniques, including ultrasonic C-scan, X-ray computed tomography (CT), and infrared (IR) thermography, were employed on ceramic matrix composites (CMCs) to illustrate defect information that might effect mechanical behavior and to analyze structural performance of CMCs. Prior to tensile testing, through C-scan and CT analyses results, the qualitative relationship between the relative ultrasonic transmitted amplitude and porosity based on CT was exhibited. An IR camera was used for in-situ monitoring of progressive damages and to determine temperature changes during tensile testing. Moreover, scanning-electron microscopy characterization was used to perform microstructural failure analyses. This paper describes the use of nondestructive evaluation (NDE) techniques to facilitate the understanding of tension behavior of CMCs.

scholarly journals Localization due to Damage in Two-Direction Fiber-Reinforced Composites

1996 ◽  
Vol 63 (2) ◽  
pp. 321-326 ◽  
Author(s):  
F. Hild ◽  
P.-L. Larsson ◽  
F. A. Leckie
Keyword(s):  
Damage Mechanics ◽  
Ceramic Matrix Composites ◽  
Continuum Damage Mechanics ◽  
General Criterion ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Damage Models ◽  
Pull Out ◽  
Fracture Features

Fiber pull-out is one of the fracture features of fiber-reinforced ceramic matrix composites. The onset of this mechanism is predicted by using continuum damage mechanics, and corresponds to a localization of deformation. After deriving two damage models from a uniaxial bundle approach, different configurations are analyzed through numerical methods. For one model some very simple criteria can be derived, whereas for the second one none of these criteria can be derived and the general criterion of localization must be used.

Mullite Fiber Reinforced Alumina Ceramic Matrix Composites

2008 ◽  
Vol 368-372 ◽  
pp. 710-712 ◽  
Author(s):  
Zhi Wang ◽  
Guo Pu Shi ◽  
Xiang Sun ◽  
Xian Qin Hou
Keyword(s):  
Sintering Temperature ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Alumina Ceramic ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Sintering Aids ◽  
Original Matrix ◽  
Pull Out ◽  
Mullite Fiber

Mullite fiber reinforced alumina ceramic matrix composites (MFACC) were prepared using CaO-MgO-SiO2 (CMS) and TiO2 as sintering aids. The effects of the contents of sintering aids and mullite fiber on the density and sintering temperature of MFACC are studied. The results showed that when the CMS content is 8.0% and the TiO2 content is 1.0%, the density of the as-sintered MFACC is 98.9%. When the mullite fiber content is 15.0% and the sintering temperature is 1450 °C, the flexural strength of the resultant composite increases to 504.5MPa, 70.7% higher than the original matrix, and the relative density of the composites reaches 98.4%. The reinforcement mechanisms are fibers pull-out and sticky point.

Effects of Meso-Structure in Grinding of 2.5D Woven Fiber-Reinforced Ceramic Composites

2017 ◽  
Vol 1142 ◽  
pp. 152-158
Author(s):  
Y.G. Wang ◽  
Chao Ding ◽  
Bin Lin
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
High Tech ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Grinding Mechanism ◽  
Specific Frequency ◽  
Specific Fracture ◽  
Ae Signals

Fiber-reinforced ceramic composites are relatively promising materials in aerospace and other high-tech area. In this work, the grinding mechanism of 2.5-dimensional woven quartz fiber-reinforced ceramic matrix composites was researched by experimental analysis. The acoustic emission (AE) combined with wavelet analysis was adopted to evaluate the grinding process. The ratio of energy which may indicate the mode of fracture of the composites was used for analyzing each of the AE signals levels. The effects of meso-structure on AE frequency distribution have been discussed. It was found that that specific frequency band is corresponding to the specific fracture mode, such as fiber fracture, interface debonding and matrix fracture. It indicates that grinding mechanism is highly dependent on the meso-structure of the composites.

scholarly journals Multiple Matrix Cracking of Fiber-Reinforced Ceramic-Matrix Composites during Operation

2020 ◽  
Author(s):  
Chengzheng Zhu
Keyword(s):  
Ceramic Matrix Composite ◽  
Weight Ratio ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Aircraft Engine ◽  
Matrix Cracking ◽  
Civil Aviation ◽  
Inlet Temperature ◽  
Flight Safety ◽  
Fiber Reinforced

In the field of civil aviation, the most important factor is safety quality. Improving aircraft performance can increase flight safety factor in some degree. To improve the thrust-to-weight ratio of aircraft engines and reduce fuel consumption, the fundamental measure is to increase the turbine inlet temperature of engines, while hot-section components is directly related to the maximum allowable operating temperature. Ceramic-matrix composite (CMC) material is one of the important candidate materials for aeroengine. To improve CMCs in aircraft engine application, it is necessary to investigate the failure mechanism of CMCs and also failure models. However, during operation, matrix multiple cracking occurs with fiber debonding and fracture, which affects the flight safety and failure risk. In this chapter, the multiple matrix cracking of fiber-reinforced CMCs is investigated using energy balance approach.

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.

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