scholarly journals Prediction of Failure in Ceramic Matrix Composites Using Damage-Based Failure Criterion

2020 ◽  
Vol 4 (4) ◽  
pp. 183
Author(s):  
Neraj Jain ◽  
Dietmar Koch
Keyword(s):  
Failure Criterion ◽  
Damage Mechanics ◽  
Shear Test ◽  
Damage Model ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Filament Winding ◽  
Material Behavior ◽  
Matrix Composites ◽  
Inelastic Behavior

This paper presents a damage-based failure criterion and its implementation in order to predict failure in ceramic matrix composites (CMC) manufactured via filament winding. The material behavior of CMCs is anisotropic and strongly depends on the angle between fiber orientation and loading direction. The inelastic behavior of laminates with different fiber orientations under tension and shear is modeled with the help of continuum damage mechanics. The parameters required for the damage model are obtained from a standard tensile and shear test. An isotropic damage law determines the evolution of damage in thermodynamic space and considers the interaction of damage parameters in different principal material directions. A quadratic damage-based failure criterion inspired by the Tsai-Wu failure criterion is proposed. Failure stress and strain can be predicted with higher accuracy compared to the Tsai-Wu failure criterion in stress- or strain-space. The use of the proposed damage limits allows designing a CMC component based on the microstructural phenomenon of stiffness loss. With the help of results obtained from modeling and experiments, fracture mechanics during the Iosipescu-shear test of CMCs and its capability to determine the shear strength of the material is discussed.

Accounting for frictional contact in an anisotropic damage model based on compliance tensorial variables, illustration on ceramic matrix composites

2018 ◽  
Vol 28 (8) ◽  
pp. 1150-1169 ◽  
Author(s):  
Emmanuel Baranger
Keyword(s):  
Damage Mechanics ◽  
A Priori ◽  
Damage Model ◽  
Ceramic Matrix Composites ◽  
Inelastic Strain ◽  
Ceramic Matrix ◽  
Thermomechanical Properties ◽  
Matrix Composites ◽  
Crack Network ◽  
Evolution Laws

Ceramic matrix composites have good thermomechanical properties at high or very high temperatures. The modeling of the crack networks associated to the degradation of such composites using damage mechanics is not straightforward. The main reason is the presence of a crack network mainly oriented by the loading direction, which is a priori unknown. To model this, compliance tensorial damage variables are used in a thermodynamic potential able to account for crack closure effects (unilateral contact). The damage kinematic is initially completely free and imposed by the evolution laws. The key point of the present paper is to account for friction in such cracks that can result in an apparent activation/deactivation of the shear damage. The initial model is enriched with an inelastic strain and a friction law. The plasticity criterion is expressed only using tensorial variables. The model is identified and illustrated on multiaxial data obtained at ONERA on tubes loaded in tension and torsion.

Extension of a fourth-order damage theory to anisotropic history: Application to ceramic matrix compostites under a multi-axial non-proportional loading

2016 ◽  
Vol 27 (2) ◽  
pp. 238-252 ◽  
Author(s):  
Emmanuel Baranger
Keyword(s):  
Damage Mechanics ◽  
A Priori ◽  
Damage Model ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Proportional Loading ◽  
Crack Network ◽  
History Of ◽  
Evolution Laws

Ceramic matrix composites have good thermo-mechanical properties at high or very high temperatures. The alliance of two brittle materials (e.g. SiC fibers and SiC matrix) via an interface allows a pseudo-ductile macroscopic behavior due to crack deviation. The modeling of the crack networks using damage mechanics is not straight forward. The main reason is the presence of a crack network oriented by the loading direction, which is not known a priori. The aim of this paper is to extend an anisotropic damage model able to describe such behaviors to multi-axial loadings. For that, compliance-like tensorial damage variables are used in a thermodynamic potential able to account for crack closure effects. The damage kinematic is initially completely free and imposed by the evolution laws. The key point of the present paper is to account for an anisotropic history of damage. The results obtained are put in relation to alternate torsion tests performed on SiC/SiC tubes and richly instrumented.

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.

EFFECTS OF AS-RECEIVED DEFECTS ON CERAMIC MATRIX COMPOSITES PROPERTIES USING HIGH- FIDELITY MICROSTRUCTURES WITH PERIODIC BOUNDARY CONDITIONS

2021 ◽  
Author(s):  
KHALED H. KHAFAGY, ◽  
ADITI CHATTOPADHYAY
Keyword(s):  
Boundary Conditions ◽  
Periodic Boundary ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Periodic Boundary Conditions ◽  
Material Behavior ◽  
Recent Effort ◽  
High Fidelity ◽  
Matrix Composites ◽  
Damage Initiation

The presence of microstructural defects in as-received specimens of ceramic matrix composites (CMCs) significantly influences their constitutive response and damage, highlighting the importance of characterization and quantification of these defects for accurate assessment of damage and failure in the service environment. In a recent effort, the authors developed an algorithm to generate stochastic representative volume elements (SRVEs) of Carbon fiber Silicon-Carbide-Nitride matrix (C/SiNC) CMCs based on extensive multiscale material and defect characterization data. This paper implements this algorithm within a commercial finite element solver with periodic boundary conditions (PBCs) for high-fidelity micromechanics analysis and investigation of macroscopic material behavior of C/SiNC composites. Different loading directions are used to predict the global mechanical properties, and the results are in excellent agreement with theoretical (rule of mixture) predictions. Subsequently, the effects of as-received defects on the global and local responses are investigated. The results show that intratow porosity has pronounced degradation effects on the global elastic properties and results in complex stress localization patterns, which can be attributed to potential damage initiation sites.

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