Comparisons of the Thermomechanical Fatigue Behavior of C/SIC and SIC/SIC Ceramic-Matrix Composites Subjected to Different Phase Angle

2018 ◽  
Vol 35 (02) ◽  
pp. 209-223
Author(s):  
L. B. Li
Keyword(s):  
Phase Angle ◽  
Fatigue Behavior ◽  
Ceramic Matrix Composites ◽  
Fatigue Loading ◽  
Thermomechanical Fatigue ◽  
Dissipated Energy ◽  
Peak Strain ◽  
Matrix Composites ◽  
Sic Composites ◽  
Phase Angles

ABSTRACTIn this paper, the comparisons of thermomechanical fatigue behavior of C/SiC and SiC/SiC fiber-reinforced ceramic-matrix composites (CMCs) subjected to different phase angles of θ = 0, π/3, π/2 and π have been investigated. The relationships between the fatigue damage mechanisms, phase angle, fatigue hysteresis dissipated energy, fatigue hysteresis modulus and fatigue peak strain, fiber/matrix interface debonding and sliding have been established. The differences between C/SiC and SiC/SiC composites under thermomechanical fatigue loading with different phase angles have been analyzed. The damage accumulation of 2.5D C/SiC and 2D SiC/SiC composites under thermomechanical fatigue loading have been predicted. With increasing of the phase angle, the fatigue hysteresis dissipated energy, fatigue peak strain and interface debonded length decrease for the SiC/SiC composite; however, for the C/SiC composite, the fatigue hysteresis dissipated energy, fatigue peak strain and the interface debonded length increase at the same cycle number.

scholarly journals Damage accumulation and lifetime prediction of fiber-reinforced ceramic-matrix composites under thermomechanical fatigue loading

2020 ◽  
Vol 39 (1) ◽  
pp. 608-619
Author(s):  
Longbiao Li
Keyword(s):  
Fatigue Life ◽  
Damage Accumulation ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Thermomechanical Fatigue ◽  
Dissipated Energy ◽  
Peak Strain ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Fatigue Lifetime

AbstractIn this paper, the damage accumulation and life prediction in fiber-reinforced ceramic-matrix composites (CMCs) subjected to thermomechanical fatigue (TMF) loading are investigated. The relationships between TMF damage mechanisms, fatigue hysteresis-based damage parameters, fraction of broken fiber, and applied cycles are established. Evolution of fatigue hysteresis dissipated energy, fatigue hysteresis modulus, fatigue peak strain, fatigue broken fiber fraction versus applied cycle curves, and the fatigue life S–N curves is analyzed. Damage accumulation and fatigue life of cross-ply silicon carbide/magnesium aluminosilicate composite under in-phase (IP)- and out-of-phase (OP)-TMF and isothermal fatigue (IF) loading are predicted. Under the same fatigue peak stress, the fatigue lifetime decreases from IF loading at 566°C to IF loading at 1,093°C, IP-TMF and OP-TMF. The TMF loading significantly reduced the fatigue lifetime of CMCs.

scholarly journals Comparisons of thermomechanical fatigue hysteresis loops of fiber-reinforced ceramic-matrix composites subjected to different phase angles

2018 ◽  
Vol 233 (6) ◽  
pp. 2015-2032 ◽  
Author(s):  
Li Longbiao
Keyword(s):  
Volume Fraction ◽  
Frictional Coefficient ◽  
Hysteresis Loops ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Thermomechanical Fatigue ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Phase Angles

In this paper, comparisons of thermomechanical fatigue hysteresis loops of fiber-reinforced ceramic-matrix composites (CMCs) subjected to different phase angles of θ = 0, π/3, π/2, and π have been investigated. The shape, location, and area of fatigue hysteresis loops are affected by the phase angle under the thermomechanical cyclic loading. The effects of fiber volume fraction, fatigue peak stress, matrix crack spacing, interface frictional coefficient, and interface debonded energy on the thermomechanical fatigue hysteresis loops and fiber/matrix interface slip of different phase angles are discussed. The fatigue hysteresis loops of cross-ply CMCs under the phase angles of θ = 0 and π are predicted for different fatigue peak stresses and cycle numbers.

scholarly journals Micromechanical Modeling Tensile and Fatigue Behavior of Fiber-Reinforced Ceramic-Matrix Composites Considering Matrix Fragmentation and Closure

2021 ◽  
Vol 5 (7) ◽  
pp. 187
Author(s):  
Longbiao Li
Keyword(s):  
Fatigue Behavior ◽  
Constitutive Models ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Fatigue Loading ◽  
Micromechanical Modeling ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
The Matrix

In this paper, micromechanical constitutive models are developed to predict the tensile and fatigue behavior of fiber-reinforced ceramic-matrix composites (CMCs) considering matrix fragmentation and closure. Damage models of matrix fragmentation, interface debonding, and fiber’s failure are considered in the micromechanical analysis of tensile response, and the matrix fragmentation closure, interface debonding and repeated sliding are considered in the hysteresis response. Relationships between the matrix fragmentation and closure, tensile and fatigue response, and interface debonding and fiber’s failure are established. Experimental matrix fragmentation density, tensile curves, and fatigue hysteresis loops of mini, unidirectional, cross-ply, and 2D plain-woven SiC/SiC composites are predicted using the developed constitutive models. Matrix fragmentation density changes with increasing or decreasing applied stress, which affects the nonlinear strain of SiC/SiC composite under tensile loading, and the interface debonding and sliding range of SiC/SiC composite under fatigue loading.

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.

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