Modeling stress-dependent matrix cracking and stress–strain behavior in 2D woven SiC fiber reinforced CVI SiC composites

2007 ◽  
Vol 67 (6) ◽  
pp. 1009-1017 ◽  
Author(s):  
G MORSCHER ◽  
M SINGH ◽  
J KISER ◽  
M FREEDMAN ◽  
R BHATT
Keyword(s):  
Matrix Cracking ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Strain Behavior ◽  
Sic Fiber ◽  
Modeling Stress ◽  
Sic Composites ◽  
Stress Dependent

Stress, Strain and Elastic Modulus Behaviour of SiC-Fiber/SiC Composites during Creep and Cyclic Fatigue Tests

1997 ◽  
Vol 132-136 ◽  
pp. 1942-1945 ◽  
Author(s):  
Mineo Mizuno ◽  
Shijie Zhu ◽  
Yutaka Kagawa ◽  
Hiroshi Kaya
Keyword(s):  
Elastic Modulus ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Stress Strain ◽  
Sic Fiber ◽  
Sic Composites

Compressive stress–strain behavior of steel fiber reinforced-recycled aggregate concrete

2014 ◽  
Vol 46 ◽  
pp. 65-72 ◽  
Author(s):  
Jodilson Amorim Carneiro ◽  
Paulo Roberto Lopes Lima ◽  
Mônica Batista Leite ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Compressive Stress ◽  
Steel Fiber ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Strain Behavior

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.

Strong Interface in CMCs, a Condition for Efficient Multilayered Interphases

1994 ◽  
Vol 365 ◽  
Author(s):  
Christine Droillard ◽  
Jacques Lamon ◽  
Xavier Bourrat
Keyword(s):  
Fracture Toughness ◽  
Bonding Strength ◽  
High Strength ◽  
Interfacial Behavior ◽  
Strain Behavior ◽  
High Toughness ◽  
Sic Fiber ◽  
Sliding Mechanism ◽  
Fiber Treatment ◽  
Sic Composites

ABSTRACTA fiber treatment was used to change the bonding strength of the Nicalon NLM 202 SiC fiber from weak to strong, in a series of 2D-SiC/SiC composites with multilayered interphases. The materials with the pre-treated fibers were compared to the same materials but reinforced with as received fibers. The stress-strain behavior and the fracture toughness were examined as a function of crack patterns identified by TEM. All the materials could be grouped into two distinct families: (i) materials reinforced with untreated fibers have a weak fiber bonding and are characterized by a low strength and a low toughness and (2) materials with the pre-treated fibers have a strong fiber bonding and are characterized by a high strength and a high toughness. This latter behavior is identified by TEM. It corresponds to a new interfacial behavior with a cohesive mode of interfacial cracking, involving branching and deflection by the successive interfaces. In the former family, the adhesive interfacial failure mode corresponds to the classical debond/sliding mechanism.

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