Applicability of Fracture Mechanics to Fiber-Reinforced CVD-Ceramic Composites

1986 ◽  
pp. 17-32 ◽  
Author(s):  
M. Gomina ◽  
J. L. Chermant ◽  
F. Osterstock ◽  
G. Bernhart ◽  
J. Mace
Keyword(s):  
Fracture Mechanics ◽  
Ceramic Composites ◽  
Fiber Reinforced

Linear translaminar fracture characterization of additive manufactured continuous carbon fiber reinforced thermoplastic

2021 ◽  
pp. 089270572110214
Author(s):  
Weiller M Lamin ◽  
Flávio LS Bussamra ◽  
Rafael TL Ferreira ◽  
Rita CM Sales ◽  
José E Baldo
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Fracture Mechanics ◽  
Image Correlation ◽  
Fiber Reinforced ◽  
Fused Filament Fabrication ◽  
Critical Energy Release Rate ◽  
Linear Elastic ◽  
Continuous Carbon Fiber ◽  
Carbon Fiber Reinforced

This work presents the experimental determination of fracture mechanics parameters of composite specimens manufactured by fused filament fabrication (FFF) with continuous carbon fiber reinforced thermoplastic filaments, based on Linear Elastic Fracture Mechanics (LEFM). The critical mode I translaminar fracture toughness (KIc) and the critical energy release rate (GIc) are found for unidirectional and cross-ply laminates. The specimens were submitted to quasi-static tensile testing. Digital Image Correlation (DIC) is used to find the stress field. The stress fields around the crack tip are compared to linear elastic finite element simulations. The results demonstrate the magnitude of fracture toughness is in the same range as for polymers and some metals, depending on lay-up configuration. Besides, fractographic analyses show some typical features as river lines, fiber impression, fiber pulls-out and porosity aspects.

Metal-Reinforced Ceramic Composites for Turbine Vanes

1972 ◽  
Author(s):  
S. A. Bortz
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Metal Fiber ◽  
Turbine Engine ◽  
Turbine Vanes ◽  
The Matrix ◽  
The Relationship ◽  
Structural Matrix

Experiments have been performed which indicate the potential of metal-fiber reinforced-ceramic matrix composites for use as a high temperature structural matrix. The results of this work reveal that metal-fiber reinforced ceramics obey compostie theory, and that after cracks occur in the matrix, a pseudo-ductility can be introduced into the composite. This toughness can be predicted from equations of work required to pull the fibers through the matrix. The relationship between strength, toughness, and crack depths, are dependent on the inter-facial bond between the fibers and matrix as well as fiber diameter and length. Based on the results of these experiments, multicomponent materials with superior resistance to failure from oxidation, thermal shock, and high mechanical stresses in air above 2400 F can be postulated. These materials have potential for use as gas turbine engine vanes.

Helium Permeability Measurement of SiC Ceramic Composites for Advanced Reactor Application

2013 ◽  
Author(s):  
Weiqian Zhuo ◽  
Fenglei Niu ◽  
Yungan Zhao ◽  
Houbo Qi ◽  
Zulong Hao ◽  
...  
Keyword(s):  
Low Cost ◽  
Ceramic Composites ◽  
Test System ◽  
Fiber Reinforced ◽  
Water Displacement ◽  
Coated Fiber ◽  
Sic Ceramic ◽  
Carbon Coated ◽  
The Difference ◽  
Reactor Application

Permeability of helium gas of Silicon carbide ceramic composites material, which is one of the most important properties in application of SiC composite for advanced reactors, is studied by using a simple, low-cost test system. The test system can not only qualitatively determine whether the sample is permeable or not, but also quantitatively measure the permeability for the permeable ones by water displacement. The tests are conducted with low pressure in room temperature. The permeability of the SiSiC composite depends on the preparation method. In four flat-plate materials prepared by different processes for the test, the splint based SiSiC and cordierite coated fiber reinforced SiSiC are hermetic, the permeability of uncoated fiber reinforced SiSiC and CVD carbon coated fiber reinforced SiSiC are 0.216cm2/s and 0.109cm2/s, which imply that the permeability is cut in half with the coating. The samples are scanned under SEM to analyze their microscopic structures and verified that the difference of permeability is related to their coatings as well as the pores and cracks.

scholarly journals INTERFACES IN SiC FIBER-REINFORCED GLASS-CERAMIC COMPOSITES

1990 ◽  
Vol 51 (C1) ◽  
pp. C1-879-C1-883
Author(s):  
L. MAZEROLLES ◽  
D. MICHEL ◽  
L. ULMER ◽  
J. L. PASTOL ◽  
M. PARLIER ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Ceramic Composites ◽  
Fiber Reinforced ◽  
Sic Fiber

Monitoring Damage in Non-Oxide Composites at High Temperatures Using Carbon-Containing CVD SiC Monofilament Fibers As Embedded Electrical Resistance Sensors

2020 ◽  
Author(s):  
Ragav P. Panakarajupally ◽  
Joseph Elrassi ◽  
K. Manigandan ◽  
Yogesh P. Singh ◽  
Gregory N. Morscher
Keyword(s):  
Crack Growth ◽  
Electrical Resistance ◽  
Composite System ◽  
Elevated Temperatures ◽  
Ceramic Composites ◽  
Fatigue Tests ◽  
Matrix Cracking ◽  
Fiber Reinforced ◽  
Damage Initiation ◽  
Sic Fiber

Abstract Electrical resistance has become a technique of interest for monitoring SiC-based ceramic composites. The typical constituents of SiC fiber-reinforced SiC matrix composites, SiC, Si and/or C, are semi-conducive to some degree resulting in the fact that when damage occurs in the form of matrix cracking or fiber breakage, the resistance increases. For aero engine applications, SiC fiber reinforced SiC, sometimes Si-containing, matrix with a BN interphase are often the main constituents. The resistivity of Si and SiC is highly temperature dependent. For high temperature tests, electrical lead attachment must be in a cold region which results in strong temperature effects on baseline measurements of resistance. This can be instructive as to test conditions; however, there is interest in focusing the resistance measurement in the hot section where damage monitoring is desired. The resistivity of C has a milder temperature dependence than that of Si or SiC. In addition, if the C is penetrated by damage, it would result in rapid oxidation of the C, presumably resulting in a change in resistance. One approach considered here is to insert carbon “rods” in the form of CVD SiC monofilaments with a C core to try and better sense change in resistance as it pertains to matrix crack growth in an elevated temperature test condition. The monofilaments were strategically placed in two non-oxide composite systems to understand the sensitivity of ER in damage detection at room temperature as well as elevated temperatures. Two material systems were considered for this study. The first composite system consisted of a Hi-Nicalon woven fibers, a BN interphase and a matrix processed via polymer infiltration and pyrolysis (PIP) which had SCS-6 monofilaments providing the C core. The second composite system was a melt-infiltrated (MI) pre-preg laminate which contained Hi-Nicalon Type S fibers with BN interphases with SCS-Ultra monofilaments providing the C core. The two composite matrix systems represent two extremes in resistance, the PIP matrix being orders of magnitude higher in resistance than the Si-containing pre-preg MI matrix. Single notch tension-tension fatigue tests were performed at 815°C to stimulate crack growth. Acoustic emission (AE) was used along with electrical resistance (ER) to monitor the damage initiation and progression during the test. Post-test microscopy was performed on the fracture specimen to understand the oxidation kinetics and carbon recession length in the monofilaments.

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