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Y. Zhang et al.
depends on the surface energy formed by cracks and debonding and the friction of
fiber pulling out, and the fiber bundle fracture almost stops.
The fourth stage: when the material enters the failure stage, the material reaches
the maximum shape variable, the matrix, interface, interlayer and fiber continue to
be damaged, the AE events of all kinds of damage continue to occur, the fiber bundle
fracture event occurs again, and the material enters the serious damage stage until
the specimen breaks. The highest point of displacement loading curve is regarded
as the sign of material failure. However, from the perspective of AE analysis, the
macroscopic failure of materials should have occurred before. The final fracture of
the material can be forewarned by the surge of acoustic emission signals.
17.5 Conclusion
The results show that the AE pattern recognition method combined with fracture
analysis can more accurately describe the evolution process of various damage mechanisms in the failure process than the stress-strain relationship alone. It is found that
the matrix crack propagation and the fiber bundle breakage events occur alternately
in the whole tensile test process, and the interface debonding and interlaminar crack
continue to occur in the whole process; the matrix crack propagation exists in the
early and later loading stages, but in the early stage, the microcrack propagation
is dominant, in the later stage, the long crack propagation is dominant, and in the
middle, the crack saturation stage is experienced.
Acknowledgements This work has been financially supported by the National Key Research and
Development Project of China (2016YFB0700503) and the National Natural Science Foundation
of China (51772244 and 11072195).
References
1. R. Naslain, Design, preparation and properties of non-oxide CMCs for application in engines
and nuclear reactors: an overview. Compos. Sci. Technol. 64(2), 155–170 (2004)
2. F. Christin, Design, fabrication, and application of thermostructural composites (TSC) like
C/C, C/SiC, and SiC/SiC composites. Adv. Eng. Mater. (2002)
3. L. Zhang, L. Chen, Y. Xu, Progress in research work of new CMC-SiC. Aeronaut. Manuf.
Technol. 1, 24–32 (2003)
4. L. Zhang, L. Cheng, Discussion on strategies of sustainable development of continuous fiber
ceramic matrix composites. Acta Materiae Compositae Sinica 24(2), 1–6 (2007)
5. Q. Lu, G. Jiang, X. Luo, L. Hu, Lightweight and non-ablation new TPS for X-37B aerospace
vehicle. Modern Def. Technol. 40(1), 16–20 (2012)
6. L. Zhi Quan, M.A. Wu-Jun, Applied research of rocket engine thrusters made of ceramic matrix
composite. J. Rocket Propuls. (2011)
7. N. Zarif Karimi, G. Minak, P. Kianfar, Analysis of damage mechanisms in drilling of composite
materials by acoustic emission. Compos. Struct. 131, 107–114 (2015)
Y. Zhang et al.
depends on the surface energy formed by cracks and debonding and the friction of
fiber pulling out, and the fiber bundle fracture almost stops.
The fourth stage: when the material enters the failure stage, the material reaches
the maximum shape variable, the matrix, interface, interlayer and fiber continue to
be damaged, the AE events of all kinds of damage continue to occur, the fiber bundle
fracture event occurs again, and the material enters the serious damage stage until
the specimen breaks. The highest point of displacement loading curve is regarded
as the sign of material failure. However, from the perspective of AE analysis, the
macroscopic failure of materials should have occurred before. The final fracture of
the material can be forewarned by the surge of acoustic emission signals.
17.5 Conclusion
The results show that the AE pattern recognition method combined with fracture
analysis can more accurately describe the evolution process of various damage mechanisms in the failure process than the stress-strain relationship alone. It is found that
the matrix crack propagation and the fiber bundle breakage events occur alternately
in the whole tensile test process, and the interface debonding and interlaminar crack
continue to occur in the whole process; the matrix crack propagation exists in the
early and later loading stages, but in the early stage, the microcrack propagation
is dominant, in the later stage, the long crack propagation is dominant, and in the
middle, the crack saturation stage is experienced.
Acknowledgements This work has been financially supported by the National Key Research and
Development Project of China (2016YFB0700503) and the National Natural Science Foundation
of China (51772244 and 11072195).
References
1. R. Naslain, Design, preparation and properties of non-oxide CMCs for application in engines
and nuclear reactors: an overview. Compos. Sci. Technol. 64(2), 155–170 (2004)
2. F. Christin, Design, fabrication, and application of thermostructural composites (TSC) like
C/C, C/SiC, and SiC/SiC composites. Adv. Eng. Mater. (2002)
3. L. Zhang, L. Chen, Y. Xu, Progress in research work of new CMC-SiC. Aeronaut. Manuf.
Technol. 1, 24–32 (2003)
4. L. Zhang, L. Cheng, Discussion on strategies of sustainable development of continuous fiber
ceramic matrix composites. Acta Materiae Compositae Sinica 24(2), 1–6 (2007)
5. Q. Lu, G. Jiang, X. Luo, L. Hu, Lightweight and non-ablation new TPS for X-37B aerospace
vehicle. Modern Def. Technol. 40(1), 16–20 (2012)
6. L. Zhi Quan, M.A. Wu-Jun, Applied research of rocket engine thrusters made of ceramic matrix
composite. J. Rocket Propuls. (2011)
7. N. Zarif Karimi, G. Minak, P. Kianfar, Analysis of damage mechanisms in drilling of composite
materials by acoustic emission. Compos. Struct. 131, 107–114 (2015)