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.

Cumulative Damage Mechanics: Characterization, Modeling, and Interpretation of Progressive Failure in Ceramics and Composites

2004 ◽  
Author(s):  
Michael G. Jenkins ◽  
Paul E. Labossie`re ◽  
Jonathan A. Salem
Keyword(s):  
Damage Mechanics ◽  
Progressive Failure ◽  
Ceramic Matrix Composites ◽  
Test Methods ◽  
Cumulative Damage ◽  
Material Behavior ◽  
Matrix Composites ◽  
Damage Models ◽  
Novel Design ◽  
Nonlinear Energy

Ceramic matrix composites (CMCs) have evolved to exhibit inherent damage tolerance through nonlinear energy absorption mechanisms while retaining the desirable attributes of their monolithic structural ceramic counterparts. Mathematical (analytic and numeric) models together with experimental measurements of this damage absorption have aided in understanding the thermomechanical behavior of CMCs. This understanding has led to improved test methods, better predictive modeling of material behavior, appropriate processing methods, and finally novel design methodologies for implementing CMCs. In this paper, background on CMC damage is presented, damage measurement and damage models are discussed and finally probabilistic aspects of constituent materials that can be used to illustrate the cumulative damage behavior of CMCs are described.

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.

scholarly journals Fracture Toughness of Carbon Nanotube-Reinforced Metal- and Ceramic-Matrix Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Y. L. Chen ◽  
B. Liu ◽  
Y. Huang ◽  
K. C. Hwang
Keyword(s):  
Fracture Toughness ◽  
Carbon Nanotube ◽  
Ceramic Matrix Composites ◽  
Short Fiber ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Soft Matrix ◽  
Bond Density ◽  
Pull Out ◽  
Toughness Enhancement

Hierarchical analysis of the fracture toughness enhancement of carbon nanotube- (CNT-) reinforced hard matrix composites is carried out on the basis of shear-lag theory and facture mechanics. It is found that stronger CNT/matrix interfaces cannot definitely lead to the better fracture toughness of these composites, and the optimal interfacial chemical bond density is that making the failure mode just in the transition from CNT pull-out to CNT break. For hard matrix composites, the fracture toughness of composites with weak interfaces can be improved effectively by increasing the CNT length. However, for soft matrix composite, the fracture toughness improvement due to the reinforcing CNTs quickly becomes saturated with an increase in CNT length. The proposed theoretical model is also applicable to short fiber-reinforced composites.

Micromechanical life prediction method of fiber-reinforced ceramic-matrix composites subjected to stochastic overloading at room temperature

2021 ◽  
pp. 146442072110085
Author(s):  
Longbiao Li
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Room Temperature ◽  
Degradation Rate ◽  
Prediction Method ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Damage Models

In this paper, a micromechanical fatigue life prediction method for fiber-reinforced ceramic-matrix composites subjected to stochastic overloading at room temperature is developed. Fatigue damage mechanisms in the matrix, interfaces, and fibers are characterized using different damage models. Relationships between the fatigue life and related degradation rate, stochastic overloading stress, and breakage of intact fibers are established. Experimental fatigue life of different C/SiC composites subjected to different stochastic overloading is predicted. For the same stochastic overloading condition, the degradation rate of fatigue life is the highest for cross-ply C/SiC composite, and the lowest for 2.5D C/SiC composite.

scholarly journals Fiber Distribution in Reinforced Ceramic Rotating Discs

1995 ◽  
Author(s):  
Francois Hild ◽  
Frederick A. Leckie
Keyword(s):  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Matrix Composites ◽  
Fiber Distribution ◽  
Rotating Disc ◽  
Pull Out ◽  
Rotating Discs ◽  
Brittle Matrix Composites ◽  
Final Failure

Fiber pull-out of fiber reinforced brittle matrix composites is an indication of final failure. The onset of this failure mechanism can be predicted using Continuum Damage Mechanics. After deriving a damage model from a uniaxial approach, different configurations are analyzed through analytical and numerical (F.E. calculations) methods. An extension to fibers in two perpendicular directions is proposed and the failure strength of a rotating disc structure is estimated. The results of the calculations are used to define an optimal fiber distribution in the radial and circumferential directions.

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