Effect of Cryogenic Temperature on the Fracture Toughness of Graphite/Epoxy Composites

2005 ◽  
Vol 128 (2) ◽  
pp. 151-157 ◽  
Author(s):  
S. G. Kalarikkal ◽  
B. V. Sankar ◽  
P. G. Ifju
Keyword(s):  
Fracture Toughness ◽  
Composite Laminates ◽  
Cryogenic Temperature ◽  
Liquid Nitrogen Temperature ◽  
Woven Composites ◽  
Cryogenic Temperatures ◽  
Textile Composite ◽  
Different Types ◽  
Cryogenic Conditions ◽  
Displacement Diagram

The research presented in this paper is an effort to better understand the interlaminar fracture behavior of graphite/epoxy composite laminates in cryogenic conditions. Double cantilever beam tests were performed on different types of specimens, at room and cryogenic temperatures, and the fracture toughness was calculated from their load-displacement diagram. Additionally, the fracture toughness of some plain-weave textile composite specimens and specimens treated with nanoparticles (38nmAl2O3) were also measured. It was observed that all specimens, with the exception of woven composites, showed deterioration in fracture toughness at the liquid nitrogen temperature. Nanoparticle treated specimens showed an improvement in fracture toughness, both at room and cryogenic temperatures compared to the control specimens. The woven composite specimens showed an increase in fracture toughness at cryogenic temperature. The results indicate that woven fiber composites may have potential in lightweight cryogenic storage systems.

Effects of the Stacking Sequence, Material Nature and Addition of an Adhesive Film on the Delamination Resistance of Woven Composite Laminates in Mode I and II

2015 ◽  
Vol 24 (1) ◽  
pp. 096369351502400
Author(s):  
P. Navarro ◽  
J. Aubry ◽  
F. Pascal ◽  
S. Marguet ◽  
J.F. Ferrero ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Composite Laminates ◽  
Woven Fabrics ◽  
Woven Composites ◽  
High Fracture Toughness ◽  
Mode I ◽  
Woven Composite ◽  
High Fracture ◽  
Adhesive Film ◽  
Woven Composite Laminates

Woven composites are well-known for their good transverse properties and for their high fracture toughness. The damage mechanisms leading to delamination in woven composites are identified in mode I and II and are compared with those occurring in unidirectional laminates. The influence of several parameters, including the draping sequence and the fibre / matrix interface on the fracture toughness of woven composite laminates is studied. Pure Mode I and Mode II tests are carried out on several carbon/epoxy and glass/epoxy woven composites configurations and the differences observed are discussed from a fractographic point of view. The study illustrates the high fracture toughness of the composites made of woven fabrics as well the influence of the orientation of the plies, the nature of the fibres and the addition of an adhesive film.

scholarly journals The Influence of Cryogenic Conditions on the Process of AA2519 Aluminum Alloy Cracking

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1555
Author(s):  
M. Kotyk ◽  
D. Boroński ◽  
P. Maćkowiak
Keyword(s):  
Fracture Toughness ◽  
Aluminum Alloy ◽  
Low Temperature ◽  
Cryogenic Temperature ◽  
American Military ◽  
Heat Treated ◽  
Curve Method ◽  
Liquid Nitrogen Bath ◽  
Cryogenic Conditions ◽  
Two Temperature

This study presents the results of tests involving determining quantities used to describe fracture toughness of a heat-treated AA2519 aluminum alloy applied in, among other things, constructing American military amphibians. These quantities were determined using the J–R curve method for two temperature values, 293 K and 77 K. The low temperature was provided by putting the tested specimen into a liquid nitrogen bath and keeping it there throughout the experiment. Based on the tests results, cryogenic conditions cause an increase in the maximum experimental value of the J–JQ integral, from 66.3 to 87.3 kJ/m2 Moreover, an analysis of the fatigue fracture microstructure revealed differences between specimens tested in ambient temperature and those tested in cryogenic temperature.

scholarly journals Fracture Toughness Analysis of Delamineted Composites under Variable Temperatures

2020 ◽  
Vol 22 (1) ◽  
pp. 171-178
Author(s):  
Meryem El Moufari ◽  
Larbi El Bakkali
Keyword(s):  
Fracture Toughness ◽  
Mechanical Loading ◽  
Composite Laminates ◽  
Failure Modes ◽  
Effect Of Temperature ◽  
Element Simulation ◽  
Different Types ◽  
Epoxy Material ◽  
Mode Energy ◽  
Safe Working

AbstractThe main goal of the present paper is to approach the modeling of one of the most important and critical failure modes for composite laminates which is known as interlaminar delamination in the aeronautical structures. The analytical model is based on a fracture mechanics approach; it’s used to estimate the total mixed mode energy release rate for composite laminates. A finite element simulation has been achieved in combination with the virtual crack closure technique (VCCT) to analyze the effect of temperature on the interlaminar fracture toughness growth of a delaminated carbon/epoxy material, namely IM7/8552 subjected to mechanical loading at variable temperatures. The developed model may serve as the basis for treating different types of thermal and mechanical loading, different stacking sequences and thickness of lamina in order to build safe working conditions for composite laminates.

Nanofillers’ Effects on Fracture Energy in Composite Aerospace Structures

2019 ◽  
Vol 827 ◽  
pp. 43-48
Author(s):  
Andrea Sellitto ◽  
Aniello Riccio ◽  
A. Russo ◽  
Antonio Garofano ◽  
Mauro Zarrelli
Keyword(s):  
Fracture Toughness ◽  
Composite Materials ◽  
Composite Laminates ◽  
Compressive Loading ◽  
Compressive Load ◽  
Numerical Procedure ◽  
Delamination Growth ◽  
Different Types ◽  
Research Programmes ◽  
Consequent Reduction

Composite materials damage behaviour is, nowadays, extensively investigated in the frame of aerospace research programmes. Among the several failure mechanisms which can affect composites, delamination can be considered as the most critical one, especially when combined to compressive loading conditions. In this context, nanofillers can represent an effective way to increase the composites fracture toughness with a consequent reduction of the delamination onset and evolution. Hence, in this paper, the toughening effect of the nanofillers on the delamination growth in composite material panels, subject to compressive load, has been numerically studied. A validated robust numerical procedure for the prediction of the delamination growth in composite materials panel, named SMXB and based on the VCCT-Fail release approach, has been used to perform numerical analyses by considering two different types of nanofillers. Reference material, without nanofillers insertion, has been used as benchmark in order to assess the capability of nanofillers to enhance the fracture toughness in composite laminates.

USS 18-8S and 18-8L

Alloy Digest ◽  
1975 ◽  
Vol 24 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Strength ◽  
Heat Treating ◽  
Cryogenic Temperatures ◽  
United States Steel Corporation ◽  
Temperature Performance ◽  
Aisi Type ◽  
Shock Resistance ◽  
Type 304 ◽  
Excellent Stability

Abstract USS 18-8S (AISI Type 304) and USS 18-8I (AISI Type 304L) are austenitic chromium-nickel steels that are easy to fabricate and weld. They combine high strength with excellent stability and shock resistance, even at cryogenic temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-305. Producer or source: United States Steel Corporation.

Cracking Response of a Concrete Wall to Cryogenic Temperature

2015 ◽  
Vol 365 ◽  
pp. 71-76
Author(s):  
Lahlou Dahmani ◽  
Rabah Hammar ◽  
Mohamed Oussalem Mechiche
Keyword(s):  
Cryogenic Temperature ◽  
Heat Conduction Problem ◽  
Outer Wall ◽  
Distribution Data ◽  
Cryogenic Temperatures ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Concrete Wall ◽  
Steel Tank ◽  
Concrete Tank

Liquefied natural gas (LNG) has the cryogenic temperature of –160°C to ensure the minimum storage volume when stored in LNG containers. Among various types of LNG storage containers, the full containment above-ground type with a double safety system (outer concrete tank and inner steel tank) is very common. Normally, the inner tank contains LNG, but when the LNG leaks from the inner tank, the outer concrete tank comes into contact with LNG. Under this accidental case, it is indispensable for the outer wall to keep the liquid tightness in order to safely contain the LNG before taking any countermeasure. It is, therefore, proposed to take up a heat conduction problem using the finite element method with the ANSYS software to obtain temperature distribution data of a concrete wall at cryogenic temperatures.

Fracture toughness of Dy123 low porosity bulks at liquid nitrogen temperature

2011 ◽  
Vol 471 (21-22) ◽  
pp. 884-888 ◽  
Author(s):  
A. Murakami ◽  
K. Otaka ◽  
T. Miura ◽  
A. Iwamoto
Keyword(s):  
Fracture Toughness ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Low Porosity
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