High mechanical performance SiC/SiC composites by NITE process with tailoring of appropriate fabrication temperature to fiber volume fraction

2009 ◽  
Vol 69 (10) ◽  
pp. 1623-1628 ◽  
Author(s):  
Kazuya Shimoda ◽  
Akira Kohyama ◽  
Tatsuya Hinoki
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Volkan Coşkun ◽  
Bülent Acar ◽  
Tarık Olğar

Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture the pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition and material properties of matrix and fiber. The designed ideal pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, the effect of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance was investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the layer-by-layer thickness and fiber volume fraction variation. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization test was performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.


2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Bülent Acar ◽  
Volkan Coşkun ◽  
Tarık Olğar

Abstract Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition, and material properties of matrix and fiber. The designed pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, effects of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance were investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the thickness of each layer separately and variation of fiber volume fraction between the layers. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization tests were performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.


2007 ◽  
Vol 352 ◽  
pp. 77-80 ◽  
Author(s):  
Katsumi Yoshida ◽  
Hideki Matsumoto ◽  
Masamitsu Imai ◽  
Kazuaki Hashimoto ◽  
Yoshitomo Toda ◽  
...  

In this study, Tyranno SA fiber cloth was coated with carbon black and SiC powder containing sintering aids by means of electrophoretic deposition method, and SiC/SiC composites with three different fiber volume fractions were fabricated using the Tyranno SA cloth by hot-pressing at 1700oC. The sufficient formation of the SiC matrix between each fiber could be observed. The composite fractured in non-brittle manner, and bending strength decreased with increasing fiber volume fraction. The crack propagation and fracture behavior depended on the fiber volume fraction. These differences in bending strength and fracture behavior would be caused by the difference in the interfacial bonding between fiber cloth and the matrix.


2008 ◽  
Vol 368-372 ◽  
pp. 1025-1027
Author(s):  
Ke Jian ◽  
Jing Yu Liu ◽  
Zhao Hui Chen ◽  
Qing Song Ma

Carbon fiber cloth reinforced silicon carbide (2D-Cf/SiC) composites were prepared through polycarbosilane(PCS) /divinylbenzene(DVB) pyrolysis with SiC as inactive filler. Effects of the molding pressure on the microstructure and mechanical properties of 2D-Cf/SiC composites were investigated. With increasing molding pressure from 0MPa to 3MPa, the fiber volume fraction of the composites was increased. As a result, the strengths of the composites were enhanced. But when the molding pressure exceeded 3MPa, SiC particles would damage the carbon fibers seriously. Therefore, although the fiber fraction of the composites was increased further, the flexural strengths of the composites were decreased. It was found that the composites fabricated with the molding pressure of 3 MPa exhibited highest flexural strength, reached 319.4 MPa.


2021 ◽  
Vol 30 ◽  
pp. 263498332110000
Author(s):  
Trenton Cersoli ◽  
Bharat Yelamanchi ◽  
Eric MacDonald ◽  
Jose Gonzalo Carrillo ◽  
Pedro Cortes

Additive manufacturing has allowed for the production of complex and mass customized geometries, but often at the expense of mechanical performance, a penalty which can be in part mitigated with the fabrication of composite parts. Thermoplastic structures fabricated with material extrusion additive manufacturing stand to be improved in terms of fracture toughness with the integration of continuous fibers. The present research program has investigated the production of a continuously reinforced filament to be used in open-source fused filament fabrication systems. Three different volume fractions of Kevlar fibers were incorporated into a polylactic acid (PLA) thermoplastic filament. It was observed that a 20% fiber volume fraction resulted in a doubling of the tensile strength relative to the unreinforced PLA parts. High-velocity impact tests were also performed on the reinforced printed thermoplastic material, and it was observed that the composite with the highest fiber volume fraction provided an impact energy resistance improved by a factor of four, relative to the plain PLA. The reinforced fibers have shown to restrain the penetration of the projectile at velocities similar to those that perforated the unreinforced PLA. The present work has demonstrated the production of printed composites without the need of modifying the extruding systems of a commercial 3D printer. This approach could represent an alternate and feasible process for producing continuously reinforced 3D-printed thermoplastic parts with utility for high-velocity impact applications.


2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.


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