Improved Structural Joint Concepts

2005 ◽  
Author(s):  
Carl May ◽  
Henry Wilson ◽  
J. Donn Hethcock ◽  
Tim Davis
Keyword(s):  
Composite Materials ◽  
Test Results ◽  
Lap Joint ◽  
Specific Strength ◽  
The Third ◽  
High Specific Strength ◽  
Joint Properties ◽  
Structural Joint ◽  
Structural Engineer ◽  
Materials Used

The joining of composite materials used in airframe structures has always presented a challenge to the structural engineer. As part of a Survivable Affordable Repairable Airframe Program (SARAP) agreement, research on three advanced joining concepts was conducted to identify and validate designs that would provide improved structural efficiency when compared to conventional joining methods. The first involves using finger joints in thin laminates to produce a joint with high specific strength compared to typical joining methods. The second utilizes a derivative of needling for stabilized dry fabric pre-forms to improve through-the-thickness laminate and joint properties. The third concept focuses on compression preload to improve the performance of a typical lap joint. Within each concept, coupon or element tests were used to validate the performance of these alternative configurations. This paper presents both analytical predictions and test results documenting the effects of these improved joining methods.

Influence of the composition of α-titanium alloys on thermal conductivity

2021 ◽  
pp. 79-86
Author(s):  
I. A. Schastlivaya ◽  
V. P. Leonov ◽  
I. V. Tretyakov ◽  
A. Yu. Askinazi
Keyword(s):  
Thermal Conductivity ◽  
Titanium Alloys ◽  
Nuclear Power ◽  
Power Plants ◽  
Operating Temperature ◽  
Unique Combination ◽  
Specific Strength ◽  
High Specific Strength ◽  
Heat Exchange Equipment ◽  
Materials Used

Among titanium alloys, modern α- and pseudo-α-alloys occupy a special place due to the unique combination of their mechanical properties, corrosion resistance, low density and high specific strength, which determines their effectiveness in various industries. Analysis of structural materials used for heat exchange equipment of nuclear power plants showed that the increase in the efficiency and compactness of tube systems made of a-titanium alloys is constrained by their thermal conductivity characteristic, which does not exceed 89 W/(m·K) at a temperature of 20°C. An exception is the VT1-0 grade alloy, the scope of which is limited to a maximum operating temperature of no more than 250°C. The paper considers the results of studies of a new titanium alloy of the Ti-Zr-Al-O composition with increased thermal conductivity for pipe systems of power equipment. 

Evaluation of Dimple Treatment for GFRP/Metal Co-Cured Joint

2006 ◽  
Vol 326-328 ◽  
pp. 1729-1732 ◽  
Author(s):  
Roysuke Matsuzaki ◽  
Motoko Shibata ◽  
Akira Todoroki
Keyword(s):  
Composite Materials ◽  
Surface Treatment ◽  
Bonding Strength ◽  
Marine Structures ◽  
Chemical Surface ◽  
Specific Strength ◽  
High Bonding Strength ◽  
High Specific Strength ◽  
Adhesive Surface ◽  
Strength And Stiffness

Since composite materials have high specific strength and stiffness, they are used for many fields such as aerospace and marine structures. According to such utilities, joining method between composites and metals must be developed. In this study, dimple treatment is carried out as a new reinforcing method for FRP/metal co-cured joint. Dimple treatment is applied to the adhesive surface of metal so that resin of FRP permeates into dimples and the strength of joints increases. It is revealed that dimple treatment achieves as high bonding strength as chemical surface treatment.

scholarly journals Composite Materials for Warship Constructions

2019 ◽  
Vol 26 (4) ◽  
pp. 135-140
Author(s):  
Lesław Kyzioł
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Natural Environment ◽  
Negative Impact ◽  
Test Results ◽  
Glass Composites ◽  
Magnetic Structures ◽  
Materials Used ◽  
Surface Modified ◽  
Modified Wood

AbstractThe article presents the basic properties of composite materials used for the construction of special ships. Static and dynamic characteristics of materials such as wood and polyester-glass composites are presented. Noteworthy are materials such as surface modified wood and polyester-glass composites with the addition of recyclate. Composite materials are widely used materials for the construction of non-magnetic warships. The article describes the properties of surface modified wood with polymethyl methacrylate and a polyester-glass composite with the addition of recyclate. The recyclate is fragmented, milled polyester-glass scrap. The content of the recyclate greatly affects the mechanical properties of the composite. The properties of the composite with the addition of recyclate depend on the recyclate content as well as the production technology and size of the recycled granulates. The test results showed that the increase in the recycled content causes a decrease in the mechanical properties of the composite. However, it should be remembered that these materials originated from waste, waste that is not subject to self-degradation, which have a very negative impact on the natural environment. At present, where there is a very large pollution of the natural environment, the processing and management of huge amounts of composite waste is an essential goal. A significant amount of recyclate significantly reduces the mechanical properties of the composite; however, the same large amount of recycled material has been transformed and used. The manufactured material and its structural elements are still non-magnetic structures and can be used on a less loaded element. The choice of material for the construction of special ships elements is determined not only by its properties but also by knowledge, experience, method of processing, economic and technical risk.

scholarly journals REVIEW OF MATERIALS AND TECHNOLOGICAL METHODS USED IN THE MANUFACTURE OF ENDOPROSTHESIS IN TRAUMATOLOGY AND ORTHOPAEDICS

2017 ◽  
Vol 2 (3) ◽  
pp. 13-17
Author(s):  
AV V Kolsanov ◽  
AN N Nikolaenko ◽  
VV V Ivanov ◽  
SA A Prichodko ◽  
PV V Platonov
Keyword(s):  
Corrosion Resistance ◽  
Musculoskeletal System ◽  
Surface Finish ◽  
High Corrosion Resistance ◽  
Specific Strength ◽  
The Third ◽  
High Specific Strength ◽  
Different Types ◽  
Low Modulus ◽  
Technological Methods

Traumas and diseases of the musculoskeletal system are the second among the causes of temporary disability of the population, and the third among the causes of disability and mortality. An effective method of treatment is endoprosthetics. ; Every year across the globe 500-1000 patients per 1 million of population require prosthetics. The development of endoprostheses is progressing in various spheres: design of the implant parts, methods of fixation, use of various materials, different types of surface finish of implants. Endoprostheses that are currently produced and used in traumatology and orthopaedics are unified, i.e. ; standardized - all of them have different size, but their shape is the same. This imposes serious limitations on the use of implantation in difficult clinical cases. The way out can be the use of personified implants, designed and manufactured with the use of modern rapid prototyping technologies. In this case, the use of titanium will fully implement the most important advantages of this direction: the best biocompatibility, high corrosion resistance, low modulus of elasticity, high specific strength and endurance.

Comparison of Natural Frequencies of Composite Cylindrical Shells: A Squared Lattice With Its Equivalent Seamless One

2010 ◽  
Author(s):  
M. H. Kargarnovin ◽  
J. E. Jam ◽  
A. H. Hashemian
Keyword(s):  
Composite Materials ◽  
Natural Frequency ◽  
Hollow Cylinder ◽  
Natural Frequencies ◽  
Outer Radius ◽  
Composite Cylinder ◽  
High Extent ◽  
Specific Strength ◽  
High Specific Strength ◽  
Strength And Stiffness

Modern Latticed composite materials whose high specific strength and stiffness are utilized in spacecraft and rocket structures to a sufficiently high extent are now widely used in primary airframe structures. In this work a comparison between squared latticed composite cylinder shells and the equivalent hollow cylinder with same weight, outer radius, length and material is done. An analytical equation is derived for natural frequency of square latticed composite shells. The first fifth modes are taken to be compared. The analytical and FEM results are shown and compared to each other. Also, as discussed, the squared lattice cylinder shell reaches to their natural frequencies easily than the equivalent hollow cylinder shell.

Study of the Possibilities of Obtaining Powder Materials by Rotational Turning with Multi-Faceted Cutters

2022 ◽  
Vol 1049 ◽  
pp. 62-68
Author(s):  
Aleksandr S. Binchurov ◽  
Yuri Gordeev ◽  
Vladimir Kuleshov ◽  
Andrew Dvoryansky ◽  
Alexei Gribanov ◽  
...  
Keyword(s):  
Composite Materials ◽  
Matrix Material ◽  
Raw Material ◽  
Powder Materials ◽  
High Plasticity ◽  
Metallic Materials ◽  
Specific Strength ◽  
High Specific Strength ◽  
Rotational Turning ◽  
Powder Metallurgy Methods

Composite materials obtained through powder metallurgy methods are increasingly applied in various industries, particularly in aviation and rocket and space equipment which use their high specific strength, resistance to high temperatures and other properties. Producers of composite materials use various metallic and non-metallic materials (fibres and powders) as fillers [1-2]. For example, the high plasticity (moldability) of aluminium powders allows utilizing them as a matrix material in moulding of composites using various methods of rolling, extrusion, and intense plastic deformation [3-5]. However, the widespread use of chip as a raw material for the production of composites is hampered by the complexities in obtaining powders with granules of the necessary shape and size.

Precipitation in Al-Li-Cu Alloys

1981 ◽  
Vol 39 ◽  
pp. 44-45
Author(s):  
J. E. O'Neal ◽  
K. K. Sankaran
Keyword(s):  
Electron Microscopy ◽  
Age Hardening ◽  
Precipitation Behavior ◽  
Zone Formation ◽  
Specific Strength ◽  
Hardening Behavior ◽  
Cu Alloys ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Structural Applications

Al-Li-Cu alloys combine high specific strength and high specific modulus and are potential candidates for aircraft structural applications. As part of an effort to optimize Al-Li-Cu alloys for specific applications, precipitation in these alloys was studied for a range of compositions, and the mechanical behavior was correlated with the microstructures.Alloys with nominal compositions of Al-4Cu-2Li-0.2Zr, Al-2.5Cu-2.5Li-0.2Zr, and Al-l.5Cu-2.5Li-0.5Mn were argon-atomized into powder at solidification rates ≈ 103°C/s. Powders were consolidated into bar stock by vacuum pressing and extruding at 400°C. Alloy specimens were solution annealed at 530°C and aged at temperatures up to 250°C, and the resultant precipitation was studied by transmission electron microscopy (TEM).The low-temperature (≲100°C) precipitation behavior of the Al-4Cu-2Li-0.2Zr alloy is a combination of the separate precipitation behaviors of Al-Cu and Al-Li alloys. The age-hardening behavior at these temperatures is characteristic of Guinier-Preston (GP) zone formation, with additional strengthening resulting from the coherent precipitation of δ’ (Al3Li, Ll2 structure), the presence of which is revealed by the selected-area diffraction pattern (SADP) shown in Figure la.

COMPARATIVE CHARACTERISTICS OF PHYSICAL AND MECHANICAL PROPERTIES OF COMPOSITE MATERIALS AND HIGH-STRENGTH STEEL 30FGSN2A

2020 ◽  
Author(s):  
I.R. Antypes ◽  
◽  
V.V. Zaitsev ◽  
Keyword(s):  
Composite Materials ◽  
High Strength Steel ◽  
Critical Stress ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Aviation Industry ◽  
Specific Strength ◽  
Aircraft Landing ◽  
Carbon Plastics ◽  
Aircraft Landing Gear

Currently, the use of composite materials is increasingly used in various areas of the national economy, including the aviation industry. The materials of this article are devoted to the study of the use of composite materials for the manufacture of aircraft landing gear in comparison with the traditionally used brand of steel. As a result of the work carried out, it was found that the slope made of carbon fiber showed a critical stress twice as high as its design made of 30xgsn2a steel. In addition, carbon plastics are superior to high-strength steel in terms of specific strength, stiffness, and tensile strength.

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