Estimate Interface Shear Stress of Woven Ceramic Matrix Composites from Hysteresis Loops

2013 ◽  
Vol 20 (6) ◽  
pp. 993-1005 ◽  
Author(s):  
Longbiao Li ◽  
Yingdong Song
Keyword(s):  
Shear Stress ◽  
Hysteresis Loops ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Interface Shear ◽  
Interface Shear Stress

A method for identifying the interface shear stress of unidirectional ceramic matrix composites

2021 ◽  
Vol 47 (1) ◽  
pp. 64-72
Author(s):  
Xiao Han ◽  
Xiguang Gao ◽  
Yunfa Jia ◽  
Weikang Meng ◽  
Yingdong Song ◽  
...  
Keyword(s):  
Shear Stress ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Interface Shear ◽  
Interface Shear Stress

Modelling of Hysteresis Behavior of Ceramic Matrix Composites

2019 ◽  
Vol 795 ◽  
pp. 180-187
Author(s):  
Xue Feng Teng ◽  
Duo Qi Shi ◽  
Xiao Guang Yang
Keyword(s):  
Shear Stress ◽  
Sliding Friction ◽  
Hysteresis Loops ◽  
Ceramic Matrix Composites ◽  
Friction Stress ◽  
Ceramic Matrix ◽  
Static Friction ◽  
Matrix Composites ◽  
Hysteresis Behavior ◽  
Macro Scale

Under cyclic loading, the fiber-reinforced ceramic matrix composites exhibits hysteresis behavior due to the friction stress. When the matrix/fiber debonding occurs, the shear stress is transferred by friction stress on the debond surface. The friction stress is derived from the equilibrium equation of debond fiber in the unit cell. The result indicates that friction shear stress of a single debond fiber can be described by bilinear law due to the static friction and sliding friction. The nonlinear characteristic of friction stress at macro scale attributes to the distribution of the fiber pullout length. The hysteresis loops arise due to the friction stress and the shape is dominated by the evolution of friction during loading/unloading process. The model decoupled the shear stress into two independent terms: the first term represents the shear stress on well bond interface and the second term represents friction shear stress on debond interface. The method developed in this paper is employed to study the hysteresis behavior of C/SiC composite subjected to arbitrary cyclic load. The hysteresis behavior of C/SiC composite is predicted and compared with experimental data.

Estimate interface frictional coefficient of ceramic matrix composites from hysteresis loops

2010 ◽  
Vol 45 (9) ◽  
pp. 989-1006 ◽  
Author(s):  
Longbiao Li ◽  
Yingdong Song
Keyword(s):  
Frictional Coefficient ◽  
Hysteresis Loops ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Fatigue Loading ◽  
Hysteresis Loss ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Interface Shear ◽  
The Matrix

An approach to estimate fiber/matrix interface frictional coefficient of ceramic matrix composites under fatigue loading is developed by means of hysteresis loops. The Coulomb friction law is adopted to describe the interface shear stress in the debonded region. The matrix crack space and interface debonded length are obtained by matrix statistical cracking model and fracture mechanics interface debonding criterion. The hysteresis loops of four different cases are derived based on the damage mechanisms of fiber sliding relative to matrix in the debonded region during unloading and subsequent reloading. The hysteresis loss energy corresponding to different cycle is formulated in terms of interface frictional coefficient. By comparing the experimental hysteresis loss energy with computational values, the interface frictional coefficient of three different ceramic matrix composites under fatigue loading is derived.

Micromechanical Modeling for Fatigue Hysteresis Loops of Fiber-Reinforced Ceramic–Matrix Composites Under Multiple Loading Stress Levels

2015 ◽  
Vol 07 (06) ◽  
pp. 1550087 ◽  
Author(s):  
Longbiao Li
Keyword(s):  
Slip Length ◽  
Hysteresis Loops ◽  
Ceramic Matrix Composites ◽  
Peak Stress ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Stress Levels ◽  
Multiple Loading

In this paper, the fatigue hysteresis loops of fiber-reinforced ceramic–matrix composites (CMCs) under multiple loading stress levels considering interface wear have been investigated using micromechanics approach. Under fatigue loading, fiber/matrix interface shear stress decreases with the increase of cycle number due to interface wear. Upon increasing of fatigue peak stress, the interface debonded length would propagate along the fiber/matrix interface. The difference of interface shear stress existing in the new and original debonded region would affect interface debonding and interface frictional slipping between fibers and matrix. Based on the fatigue damage mechanism of fiber slipping relative to matrix in the interface debonded region upon unloading and subsequent reloading, the interface debonded length, unloading interface counter-slip length and reloading interface new-slip length are determined by fracture mechanics approach. The fatigue hysteresis loop models under multiple peak stress levels have been developed. The effects of fiber volume fraction, fatigue peak stress, matrix crack spacing, interface debonding and interface wear on interface slip and fatigue hysteresis loops have been analyzed.

Damage evolution of carbon fiber-reinforced ceramic-matrix composites with different fiber preforms using the fatigue hysteresis loop area

2016 ◽  
Vol 88 (5) ◽  
pp. 532-551 ◽  
Author(s):  
Longbiao Li
Keyword(s):  
Shear Stress ◽  
Hysteresis Loop ◽  
Ceramic Matrix Composites ◽  
Inert Atmosphere ◽  
Matrix Composites ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Loop Area ◽  
Hysteresis Loop Area ◽  
Fiber Preforms

The damage evolution of C/SiC ceramic-matrix composites with different fiber preforms, that is, unidirectional, cross-ply and 2.5D woven, under cyclic fatigue loading at room and elevated temperatures in air and inert atmosphere has been investigated. The experimental fatigue hysteresis modulus and hysteresis loop area versus cycle numbers have been analyzed. The relationships between the fatigue hysteresis loop area, interface slip and interface shear stress have been established. The evolution of the fatigue hysteresis loop area and interface shear stress as a function of applied cycles has been analyzed for different peak stresses, fiber preforms and test conditions. For different fiber preforms and test conditions, the fatigue hysteresis loop area degrades the fastest for unidirectional C/SiC at 800℃ in air, and the slowest for 2.5D C/SiC at 600℃ in an inert atmosphere, due to the different degradation rates of interface shear stress.

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