High-Performance Linear Cable Transmission

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Joan Savall ◽  
Javier Martín ◽  
Alejo Avello
Keyword(s):  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Negative Effects ◽  
Low Friction ◽  
Alternative Design ◽  
Cable Length ◽  
High Stiffness ◽  
Length Changes

Cable transmissions offer several advantages such as high stiffness to weight ratio, high strength, low friction, and absence of backlash, which makes them appropriate for demanding mechanical applications. However, while extensively used as rotational transmissions, there are only a few examples of linear cable transmissions in the literature. The reason is that the up-to-date designs are based on a cable layout that leads to cable length changes during movement. This, in turn, produces negative effects such as transmission nonlinearity and cable fatigue. In this paper, an alternative design for linear cable transmissions is presented. The new design overcomes the aforementioned problems through a proper cable layout. Different applications of the new transmission are reported, validating the proposed design.

scholarly journals Fused Filament Fabrication of PEEK: A Review of Process-Structure-Property Relationships

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1665 ◽  
Author(s):  
Ali Reza Zanjanijam ◽  
Ian Major ◽  
John G. Lyons ◽  
Ugo Lafont ◽  
Declan M. Devine
Keyword(s):  
High Performance ◽  
Space Station ◽  
Weight Ratio ◽  
High Strength ◽  
Structure Property ◽  
Fused Filament Fabrication ◽  
Space Applications ◽  
Structure Property Relationships ◽  
Complex Design ◽  
Process Structure

Poly (ether ether ketone) (PEEK) is a high-performance engineering thermoplastic polymer with potential for use in a variety of metal replacement applications due to its high strength to weight ratio. This combination of properties makes it an ideal material for use in the production of bespoke replacement parts for out-of-earth manufacturing purposes, in particular on the International Space Station (ISS). Additive manufacturing (AM) may be employed for the production of these parts, as it has enabled new fabrication pathways for articles with complex design considerations. However, AM of PEEK via fused filament fabrication (FFF) encounters significant challenges, mostly stemming from the semi crystalline nature of PEEK and its associated high melting temperature. This makes PEEK highly susceptible to changes in processing conditions which leads to a large reported variation in the literature on the final performance of PEEK. This has limited the adaption of FFF printing of PEEK in space applications where quality assurance and reproducibility are paramount. In recent years, several research studies have examined the effect of printing parameters on the performance of the 3D-printed PEEK parts. The aim of the current review is to provide comprehensive information in relation to the process-structure-property relationships in FFF 3D-printing of PEEK to provide a clear baseline to the research community and assesses its potential for space applications, including out-of-earth manufacturing.

A Comparative Assessment of Austempered Ductile Iron as a Substitute in Weight Reduction Applications

2008 ◽  
Author(s):  
Ashwin Polishetty ◽  
Sarat Singamneni ◽  
Guy Littlefair
Keyword(s):  
Ductile Iron ◽  
High Performance ◽  
Material Selection ◽  
Weight Ratio ◽  
Cost Savings ◽  
High Strength ◽  
Good Choice ◽  
Comparative Assessment ◽  
Austempered Ductile Iron ◽  
Machining Characteristics

Manufacturing engineering has had to undergo drastic changes in the approach to material selection in order to meet new design challenges. In the automotive industry, researchers in their effort to reduce emissions and satisfy environmental regulations, have shifted their focus to new emerging materials such as high-strength aluminium alloys, metal matrix composites, plastics, polymers and of late, Austempered Ductile Iron (ADI). ADI is a good choice for design where the criterion is high performance at reduced weight and cost. The unique, ausferrite microstructure gives the material desirable material properties and an edge over other materials. A comparative study of ADI in terms of materials properties and machining characteristics with other materials is desirable to highlight the potential of the material. This paper focuses on a comparative assessment of material and machining characteristics of ADI for different applications. The properties under consideration are machinability, weight and cost savings and versatility. ADI has a higher strength-to-weight ratio than aluminium making it a ready alternative for material selection. In terms of machinability, there are some problems associated with machining of ADI due to its work hardening nature. This paper attempts to identify the possible potential applications of ADI, by critically reviewing specific applications such as machinability, overall economics and service.

Investigation of Residual Stresses Distribution in Titanium Weldments

2014 ◽  
Vol 777 ◽  
pp. 171-175 ◽  
Author(s):  
Shao Pin Song ◽  
Anna M. Paradowska ◽  
Ping Sha Dong
Keyword(s):  
Residual Stresses ◽  
High Performance ◽  
Weight Ratio ◽  
Welding Process ◽  
High Strength ◽  
Naval Research ◽  
Office Of Naval Research ◽  
And Performance ◽  
Superior Corrosion Resistance ◽  
The University

Titanium and its alloys have increasingly become a material of choice for applications in high-performance structures due to their superior corrosion resistance and high strength-to-weight ratio. However, in contrast to conventional steel alloys, there exist little design and manufacturing experience in the heavy fabrication industry with large welded structures made of titanium materials. In addressing the above concern, the University of New Orleans funded by Office of Naval Research (ONR) initiated program on investigation of manufacturability and performance of a titanium mid-ship section. The uniqueness of this program is its focus upon a representative full-size mid-ship section upon which relevant scientific and technological challenges are simulated and experimentally validated. This paper reports the measurements of residual stresses using neutron diffraction in titanium T-joints. The residual stresses were measured using Engin-X at ISIS (UK) and the Kowari Strain Scanner at ANSTO (Australia). This experimental research was used to validate our in house predictions and significantly improved the knowledge and understanding of the welding process of titanium alloys.

scholarly journals Recent studies on particulate reinforced AZ91 magnesium composites fabricated by Stir casting – A review

2020 ◽  
Vol 4 (2) ◽  
pp. 115-126
Author(s):  
Anil K. Matta ◽  
Naga S. S. Koka ◽  
Sameer K. Devarakonda
Keyword(s):  
High Performance ◽  
Matrix Material ◽  
Weight Ratio ◽  
High Strength ◽  
Casting Process ◽  
Stir Casting ◽  
Critical Conditions ◽  
Matrix Composites ◽  
The Matrix ◽  
Magnesium Composites

Magnesium Metal Matrix Composites (Mg MMC) have been the focus of consideration by many researchers for the past few years. Many applications of Mg MMCs were evolved in less span of time in the automotive and aerospace sector to capture the benefit of high strength to weight ratio along with improved corrosion resistance. However, the performance of these materials in critical conditions is significantly influenced by several factors including the fabrication methods used for processing the composites. Most of the papers addressed all the manufacturing strategies of Mg MMC but no paper was recognized as a dedicated source for magnesium composites prepared through stir casting process. Since stir casting is the least expensive and most common process in the preparation of composites, this paper reviews particulate based Mg MMCs fabricated with stir casting technology. AZ91 series alloys are considered as the matrix material while the effect of different particle reinforcements, sizes , weight fractions on mechanical and tribological responses are elaborated in support with micro structural examinations. Technical difficulties and latest innovations happened during the last decade in making Mg MMCs as high performance material are also presented.

Processing, Properties, and Uses of Lightweight Glass Fiber/Aluminum Hybrid Structures

2022 ◽  
pp. 101-120
Author(s):  
Noureddine Ramdani ◽  
Mohammed Seddik Razali
Keyword(s):  
Glass Fiber ◽  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Fiber Reinforced ◽  
Metallic Structures ◽  
Reinforced Plastics ◽  
Industrial Sectors ◽  
Glass Fiber Reinforced ◽  
Processing Properties

The replacement of heavy metallic structures by high-performance lightweight composite materials is a prominent solution to fulfill the continuous demand in different industrial sectors. Lightweight structures based on aluminum-glass fiber reinforced plastics (GFRP) sandwich panels have been increasingly utilized in the shipbuilding, automotive, and aerospace industries for their striking mechanical and physical properties. These advantageous properties have resulted from the combination of the high tensile and flexural strengths, increased hardness, and the improved wear-resistance of aluminum laminate with the unique properties of lightweight stiffness and high strength weight ratio of glass fiber-reinforced. In this chapter, the various processing approaches, properties, and applications of these sandwich structures are summarized from a wide range of literature.

An Improved Size, Matching, and Scaling Method for the Design of Deterministic Mesoscale Truss Structures

2011 ◽  
Author(s):  
Patrick S. Chang ◽  
David W. Rosen
Keyword(s):  
High Performance ◽  
Design Method ◽  
Weight Ratio ◽  
High Strength ◽  
Original Method ◽  
Topological Optimization ◽  
Truss Structures ◽  
Scaling Method ◽  
Element Analysis ◽  
And Performance

Mesoscale truss structures are cellular structures that have support elements on the order of centimeters. These structures are engineered for high performance and have applications in industries where a high strength-to-weight ratio is desired. However, design of mesoscale truss structures currently requires some form of topological optimization that slows the design process. In previous research, a new Size, Matching and Scaling method was presented that eliminated the need for topological optimization by using a solid-body finite element analysis combined with a library of lattice configurations to generate topologies. When compared to topological optimization, results were favorable: design times were significantly reduced and performance results were comparable. In this paper, we present a modified Size Matching and Scaling design method that addresses key issues in the original method. Firstly, we outline an improve methodology. Secondly, we expand the library of configurations in order to improve lattice performance. Finally, we test the updated method and library against design examples.

scholarly journals Hyperelastic modelling of yarn structures for dynamic applications

2018 ◽  
Vol 183 ◽  
pp. 01031
Author(s):  
Pietro del Sorbo ◽  
Jeremie Girardot ◽  
Frederic Dau ◽  
Ivan Iordanoff
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Weight Ratio ◽  
High Strength ◽  
Material Model ◽  
Linear Elastic ◽  
Mesoscopic Models ◽  
First Results ◽  
Hyperelastic Model ◽  
The Impact

Dry fabrics comprised of high performance polymeric fibers have been widely used as protection layers in structures submitted to high velocity impacts (HVI). Their outstanding impact energy dissipation ability combined with an high strength-to-weight ratio make them a preferable choice in different applications such as bullet vests or blade containment systems over standard materials. Among the different approaches adopted to study these structures numerical methods assume a central role. Thanks to their reduced costs and the related possibility of evaluating the effects of single phenomena, they are often used to predict the structure ballistic limits or to study the physical events which occur during the penetration. Among the different strategies adopted to model a fabric, mesoscopic models have been largely adopted by different authors. These models assume the yarns as a continuum body while the fabric geometry is explicitly described. Nowadays yarn material models are universally assumed to be linear elastic and orthotropic. This modelling approach mostly focuses on the longitudinal behaviour of the yarn, however fiber-scale analyses and experimental results shows the importance of three-dimensional stress state on the ballistic limit. In order to obtain a three-dimensional description of the yarn strain state during the impact, a novel hyperelastic model for yarn structures here is developed. In a first step, fiber-level preliminary analyses have been performed to obtain the effective behaviour of these structure under the projectile collision. In the second step, the hyperelastic model has been implemented and identified thanks to microscopic elementary tests. Finally, a continuum model of the yarn have been performed. First results show the relevance of the hyperelastic model compared to the fiber-level observation and enhance the limit of the classical linear elastic material model.

Tensile Strength of Single Electrospun Nanofibers

2011 ◽  
Vol 175-176 ◽  
pp. 294-298 ◽  
Author(s):  
Kai Wei ◽  
Jian Hua Xia ◽  
Naotaka Kimura ◽  
Taiki Nakamura ◽  
Zhi Juan Pan ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
High Performance ◽  
Spider Silk ◽  
Natural Fibers ◽  
Small Diameter ◽  
Weight Ratio ◽  
Electrospun Nanofibers ◽  
High Strength ◽  
Small Scale ◽  
Structure Property

Researchers have paid much attention to small-scale natural fibers among the biological materials to seek innovative methods in order to create new high performance materials. Recently, spider dragline silk fibers are being studied because of their unique combination of high strength to weight ratio and high extensibility, which leads to a tough and lightweight fiber. Biomimetic fibers based on spider silk have been a focus of research for the past decade. However, there are still many unanswered questions about the mechanisms by which silk achieves its unique mechanical properties, as well as challenges in mechanical testing of electrospinning silk nanofibers which are often hindered by both small diameters and limited material availability. A method to characterize local mechanical behavior in small diameter nanofibers was developed to both improve understanding of structure-property in natural fibers and provide a method for comparing mechanical behavior in natural and electrospinning fibers.

On the Realization of Filament Wound Composite Impeller for Water Refrigerant

2009 ◽  
Author(s):  
Qubo Li ◽  
Jifeng Wang ◽  
Norbert Mu¨ller
Keyword(s):  
Production Process ◽  
High Speed ◽  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Filament Winding ◽  
Automatic Production ◽  
Filament Wound ◽  
Filament Wound Composite ◽  
High Speed Rotation

In the present work, the concept of composite impeller through automatic filament winding manufacturing approach was realized. The advantage of using filament winding method to manufacture high performance and light-weight composite impellers is that the production can be rapid, inexpensive and utilize commercially available winding machines. This work focuses both on how to achieve the automation of the production process, as well as evaluate the composite impeller’s mechanical properties. For the automatic production process, a new filament winding facility for manufacturing fiber-reinforced composite impellers was developed. A kevlar/epoxy matrix was selected to manufacture the high strength-to-weight ratio composite material. In order to maintain the epoxy’s freshness, a two component syringe dispensing device was designed to control the dispensation of resin. The composite material’s properties were measured in order to ensure the impeller was able to withstand the large stresses incurred during the high speed rotation required to achieve large volume flows and a high compression ratio. With these properties, a 3D structural analysis using ANSYS was performed, which resulted in a maximum tip speed of 830m/s before the composite impeller’s failure. In terms of momentum change, this is a high tip speed needed to compress water vapor.

scholarly journals Ceramic Small Gas Turbine Technology Demonstrator

1990 ◽  
Author(s):  
Tibor Bornemisza
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Ceramic Materials ◽  
Inlet Temperature ◽  
Development Effort ◽  
Turbine Wheel ◽  
Turbine Inlet

Requirements for increased power density, improved fuel economy, and rapid start demand higher turbine inlet temperatures and turbine wheel tip speeds, resulting in the need for materials with high strength to weight ratio at temperatures in excess of 2000°F. High performance ceramics appear to be the most promising substitutes for the current cobalt-nickel based superalloys. The numerous advantages of ceramics are coupled with several unfavorable properties, such as the brittleness, the low reliability of the ceramic pans, and the lack of established design, manufacturing and inspection techniques. The development of reliable components requires a close cooperation between the user and the manufacturer of the high performance ceramics. Sundstrand Power Systems has been involved with the development of ceramic gas turbine components since 1972. The current Research and Development effort involves the demonstration of ceramic turbine components operating at 2200°F turbine inlet temperature. Silicon nitride turbine wheel and stationary components were designed and subjected to a series of tests in the Gemini small gas turbine modified for this purpose. Engine start to full speed in 2.5 seconds and continuous operation at 2300°F was demonstrated. The successful testing of the ceramic turbine components demonstrated the feasibility of the currently available structural ceramic materials for non-flight-critical and unmanned turbine applications.

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