Mechanical hysteresis and damage evolution in C/SiC composites under fatigue loading at room and elevated temperatures

Considering thermal residual stress and initial matrix crack, the cylinder FEM analysis model for C/SiC tow was established. The cohesive element and damage criterions were introduced to simulation the initiation and propagation of interphase crack processes of C/SiC composites. The thermal residual stresses release with the initial matrix crack and the cracking on interphase. The interphase crack length was dominated by the performance of interphase. Analysis demonstrated that the CZM model can simulate well the thermal residual stress and the delamination of the interphase.

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Mechanical Behavior of 2D C/SiC Composites at Elevated Temperatures under Uniaxial Compression

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.462-463.1 ◽

2011 ◽

Vol 462-463 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Tao Suo ◽

Yu Long Li ◽

Ming Shuang Liu

Keyword(s):

Compressive Strength ◽

High Temperature ◽

Carbon Fiber ◽

Mechanical Behavior ◽

Uniaxial Compression ◽

Room Temperature ◽

Elevated Temperatures ◽

Carbon Matrix ◽

Structural Applications ◽

Sic Composites

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.

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Failure Mechanisms of 3-D Woven Sic/Sic Composites Under Tensile and Flexural Loading at Room and Elevated Temperatures

Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 7/8 - Ceramic Engineering and Science Proceedings ◽

10.1002/9780470313954.ch42 ◽

2008 ◽

pp. 420-432 ◽

Cited By ~ 2

Author(s):

Abhisak Chulya ◽

John Z. Gyekenyesi ◽

John P. Gyekenyesi

Keyword(s):

Elevated Temperatures ◽

Failure Mechanisms ◽

Flexural Loading ◽

Sic Composites

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Effect of Impact-Fatigue on Damage in Adhesive Joints

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.347.653 ◽

2007 ◽

Vol 347 ◽

pp. 653-658 ◽

Cited By ~ 2

Author(s):

Juan Pablo Casas-Rodriguez ◽

Ian A. Ashcroft ◽

Vadim V. Silberschmidt

Keyword(s):

Damage Evolution ◽

Weight Ratio ◽

High Strength ◽

Fatigue Loading ◽

Lap Joints ◽

Adhesive Joints ◽

Bonded Joints ◽

Impact Fatigue ◽

Adhesively Bonded ◽

Low Velocity

In recent decades the use of structural adhesive joints in the aerospace industry has increased considerably thanks to their high strength-to-weight ratio, low stress concentration and capacity to join different adherends. There is increasing interest in damage due to low-velocity impacts produced in adhesively bonded components and structures by vibrating loads. This type of loading is known as impact fatigue. The main aim of this paper is to investigate damage evolution in adhesive joints subjected to impact-fatigue and to compare this with damage evolution in standard fatigue (i.e. non-impacting, constant amplitude, sinusoidal fatigue). In this work, adhesively bonded lap joints were subjected to multiple tensile impacts tensile and it was seen that this type of loading was extremely damaging compared to standard fatigue. A number of methods of studying damage evolution in bonded joints subjected to fatigue and impact fatigue loading have been investigated and various parameters have been used to characterise these processes. Two modifications of the accumulated time-stress model [1-4] are proposed and it is shown that both models provide a suitable characterization of impact-fatigue in bonded joints.

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Damage Theoretical Analysis of 2.5D C/SiC Composites under Tensile and Shear Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.330 ◽

2010 ◽

Vol 150-151 ◽

pp. 330-333

Author(s):

Yan Jun Chang ◽

Ke Shi Zhang ◽

Gui Qiong Jiao ◽

Jian Yun Chen

Keyword(s):

Constitutive Model ◽

Damage Evolution ◽

Yield Function ◽

Shear Loading ◽

Isotropic Hardening ◽

Shear Tests ◽

Energy Equivalence ◽

Damage Constitutive Model ◽

Sic Composites ◽

Nonlinear Hardening

An anisotropic damage constitutive model is developed to describe the damage behavior of C/SiC composites. Different kinematic and isotropic hardening functions were employed in damage yield function to describe accurately the damage nonlinear hardening. The damage variable is defined by the principle of energy equivalence. The degradation of stiffness and the unrecoverable deformation induced by micro-crack propagation were considered in this model. The constants of constitutive model are identified and the damage evolution processes under tensile and shear loading. Uniaxial tension and shear tests have been used to valid the constitutive model to C/SiC composites.

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