In‐plane shear damage behaviours of 2D needled C/SiC composites

Abstract

Understanding the in‐plane shear behaviour of composites is essential to establish the design basis for practical applications. This study aims to investigate the shear damage behaviours of 2D needled C/SiC composites by various characterization techniques. The effect of layer arrangement on shear modulus and strength was discussed via shear stress‐strain responses. The shear strain field evolution and uniformity variation were studied by digital image correlation. It shows that the uniformity of shear strain field changes with the shear load, and the shear strain field evolution consist of 5 stages. The electrical resistivity measurement results indicate that structural deformation and damage evolution caused the electrical resistivity change. Furthermore, the damage evolution has a double effect on the electrical resistivity variation. The acoustic emission monitoring shows that the shear damage evolution is a 3‐stage nonlinear process before failure. The shear damages were categorized via acoustic characteristics. Besides, the postfailure behaviours were also discussed in this study.

Shear failure evolution and its dispersion of plain woven ceramic matrix composites z‐pin structure

“…The porosity of the specimen is 10%. The density of the specimen is 2.6 g/cm 3 . The specimen was fabricated via CVI.…”

“…Silicon-carbon-fiber-reinforced silicon carbide matrix composites (SiC f /SiC) are regarded as one of the most promising materials for aircraft hot section components due to their excellent mechanical properties in hightemperature environments. [1][2][3][4][5][6][7][8][9] When assembling complex high-temperature section components, ceramic-matrix composites (CMCs) joints with high mechanical properties are used to ensure the structural strength of the joint. 10,11 The 2D CMCs z-pinned joint is a mechanical joint with excellent performance, which could be widely used in the connection of complex aircraft thermal sections in the future.…”

“…Silicon–carbon–fiber‐reinforced silicon carbide matrix composites (SiC f /SiC) are regarded as one of the most promising materials for aircraft hot section components due to their excellent mechanical properties in high‐temperature environments 1–9 . When assembling complex high‐temperature section components, ceramic–matrix composites (CMCs) joints with high mechanical properties are used to ensure the structural strength of the joint 10,11 .…”

Effect of BN interfacial layer on the mechanical behavior of SiC fiber reinforced SiC ceramic matrix composites

“…Near stoichiometric ratio SiC fiber reinforced SiC ceramic matrix composites have the characteristics of lightweight, oxidation resistance, and high‐temperature resistance, especially its long‐term use temperature up to 1350°C, which makes it an ideal material system for the hot end component of aeroengine with high thrust‐weight ratio and the thermal protection system of aircraft with high Mach number 1–11 . The interfacial layer is a bond connecting the reinforced phase fiber and the continuous phase matrix.…”

“…Near stoichiometric ratio SiC fiber reinforced SiC ceramic matrix composites have the characteristics of lightweight, oxidation resistance, and high-temperature resistance, especially its long-term use temperature up to 1350 • C, which makes it an ideal material system for the hot end component of aeroengine with high thrust-weight ratio and the thermal protection system of aircraft with high Mach number. [1][2][3][4][5][6][7][8][9][10][11] The interfacial layer is a bond connecting the reinforced phase fiber and the continuous phase matrix. Its principal function is to optimize the mechanical behavior of the ceramic matrix composite under external load by adjusting the bonding strength between the fiber and the matrix to realize the strengthening and toughening effect of the ceramic matrix composite.…”