On Optimum Fibre Orientation in an Annulus

1969 ◽  
Vol 73 (703) ◽  
pp. 593-594
Author(s):  
E. H. Mansfield ◽  
Carol Hanson
Keyword(s):  
Fibre Orientation ◽  
High Strength ◽  
Stress Pattern ◽  
Carbon Fibres ◽  
Optimum Arrangement ◽  
Strength And Stiffness ◽  
Applied Stresses

The development of carbon fibres which exhibit high strength and stiffness raises many problems in the design of such fibre reinforced structures. One such problem concerns the optimum arrangement of fibres to support a given load system or load envelope, and this has been treated by Harris for planar load envelopes bounded by given values of applied stresses σX, σY and τXY . Here we consider a problem of optimum fibre arrangement to transfer a torque T across an annulus bounded by inner and outer radii r 0 and kr 0, respectively. This problem is much simpler than Harris', insofar as only one load system is considered, but it differs insofar as the stress pattern is not isotropic.

In situ observation of the martensitic transformation in (Mg,Y)-PSZ

1986 ◽  
Vol 44 ◽  
pp. 500-501
Author(s):  
R-R. Lee
Keyword(s):  
Martensitic Transformation ◽  
High Strength ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Considerable Potential ◽  
Transmission Electron ◽  
Structural Applications ◽  
Applied Stresses ◽  
Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

scholarly journals Materials for Automotive Lightweighting

2019 ◽  
Vol 49 (1) ◽  
pp. 327-359 ◽  
Author(s):  
Alan Taub ◽  
Emmanuel De Moor ◽  
Alan Luo ◽  
David K. Matlock ◽  
John G. Speer ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
New Materials ◽  
Specific Strength ◽  
Advanced High Strength Steels ◽  
Strength And Stiffness ◽  
The Cost

Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.

New porous silicon carbide composite reinforced by intact high-strength carbon fibres

2006 ◽  
Vol 26 (9) ◽  
pp. 1715-1724 ◽  
Author(s):  
Juliane Mentz ◽  
Marcus Müller ◽  
Meinhard Kuntz ◽  
Georg Grathwohl ◽  
Hans Peter Buchkremer ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Porous Silicon ◽  
High Strength ◽  
Carbon Fibres ◽  
Porous Silicon Carbide ◽  
Carbide Composite

Analysis of flaws in high-strength carbon fibres from mesophase pitch

1980 ◽  
Vol 15 (10) ◽  
pp. 2455-2465 ◽  
Author(s):  
Janice Breedon Jones ◽  
John B. Barr ◽  
Robert E. Smith
Keyword(s):  
High Strength ◽  
Mesophase Pitch ◽  
Carbon Fibres

scholarly journals Biomimetic Composites with Enhanced Toughening Using Silk Inspired Triblock Proteins and Aligned Nanocellulose Reinforcements

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Kristaps Jaudzems ◽  
...  
Keyword(s):  
Spider Silk ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Beta Sheets ◽  
Conformational Switching ◽  
Multiple Length Scales ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Flow Alignment

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.<br>

Experimental study on seismic behaviors of beam with concrete-encased steel truss

2018 ◽  
Vol 21 (13) ◽  
pp. 2018-2029
Author(s):  
Xide Zhang ◽  
Zhiheng Deng ◽  
Xiaofang Deng ◽  
Jingwei Ying ◽  
Tao Yang ◽  
...  
Keyword(s):  
High Strength ◽  
Force Model ◽  
Restoring Force ◽  
Restoring Force Model ◽  
Steel Truss ◽  
Different Types ◽  
Energy Dissipation Capacity ◽  
Load Displacement ◽  
Strength And Stiffness ◽  
Seismic Behaviors

To evaluate the ductility and energy dissipation capacity of the beam with concrete-encased steel truss, eight specimens with different types of steel truss, reinforcement ratios, and shear span ratios were tested by low-cyclic loading regime. The results indicated that beams with concrete-encased steel truss performed plumped load–displacement hysteretic loops as well as high strength and stiffness. Moreover, cross-web members improved their seismic behavior more effectively than non-cross-web members. Finally, the restoring force model of concrete-encased steel truss beam is proposed in accordance with the experimental results, which can be used to predict the load–displacement behavior of concrete-encased steel truss beam. The results could also provide a reference for the design and application of concrete-encased steel truss beam in practice.

Influence of the base material on the mechanical behaviors of polycrystal-like meta-crystals

2021 ◽  
pp. 2150004
Author(s):  
J. Lertthanasarn ◽  
C. Liu ◽  
M.-S. Pham
Keyword(s):  
Synergistic Effects ◽  
High Surface ◽  
Base Material ◽  
High Strength ◽  
Yield Stability ◽  
Yield Behavior ◽  
Specific Strength ◽  
Base Materials ◽  
Lattice Materials ◽  
Strength And Stiffness

Architected lattice metamaterials offer extraordinary specific strength and stiffness that can be tailored through the architecture. Meta-crystals mimic crystalline strengthening features in crystalline alloys to obtain high strength and improved post-yield stability of lattice materials. This study investigates synergistic effects of the base material’s intrinsic crystalline microstructure and architected polycrystal-like architecture on the mechanical behavior of architected metamaterials. Four different polygrain-like meta-crystals were fabricated from 316L, Inconel 718 (IN718) and Ti6Al4V via laser powder bed fusion (L-PBF). While the elastic modulus of the meta-crystals did not vary significantly with the base material or the number of meta-grains, the strength of the meta-crystals showed strong increasing correlation with reducing the size of meta-grains. The differences between meta-crystals made by the three alloys were the most substantial in the post-yield behavior, where the 316L meta-crystals were the most stable while Ti6Al4V meta-crystals were the most erratic. The differences in the post-yield behavior were attributed to the base material’s ductility and intrinsic work-hardening. For all base materials, increasing the number of meta-grains improved the post-yield stability of meta-crystals. The tolerance to the processing defects also differed with the base material. Detrimental defects such as the high surface roughness on the downskin of the struts or the large, irregularly shaped pores near the surface of the struts led to early strut fracture in Ti6Al4V meta-crystals. In contrast, ductile IN718 was able to tolerate such defects, enabling the most significant synergistic strengthening across lengthscales to achieve architected materials of low relative density, but with a very high strength and an excellent energy absorption.

scholarly journals High strength and low weight hollow carbon fibres

2017 ◽  
Vol 254 ◽  
pp. 042017 ◽  
Author(s):  
T. Köhler ◽  
R. Brüll ◽  
F. Pursche ◽  
J. Langgartner ◽  
G. Seide ◽  
...  
Keyword(s):  
High Strength ◽  
Carbon Fibres ◽  
Low Weight ◽  
Hollow Carbon

scholarly journals Improved numerical analysis of structures reinforced by composite FRP: Hygrothermal and prestressing loads with taper effect

2019 ◽  
Vol 28 ◽  
pp. 096369351985836
Author(s):  
Mohammed Amine Hebbaz ◽  
Bachir Kerboua ◽  
Mostapha Tarfaoui
Keyword(s):  
Interfacial Shear Stress ◽  
High Strength ◽  
Interfacial Stress ◽  
Steel Plates ◽  
Steel Beams ◽  
Original Research ◽  
Frp Composites ◽  
Prestressing Force ◽  
Numerical Finite Element ◽  
Strength And Stiffness

Fiber-reinforced polymer (FRP) composites are becoming suitable and substantial materials in repairing and replacing conventional metallic materials because of their high strength and stiffness. Steel beams can be strengthened in flexure using bonded FRP or using steel plates. In such plated beams, shear forces develop in the bonded beam and these will be transferred to the FRP plate via the adhesion technique. Thus, the interfacial shear stress and normal stress will develop consequently, and debonding may occur at the FRP plate ends due to high interfacial stress values in this area. This original research aims to study the debonding phenomenon using an analytical and a numerical finite element models, in order to identify the interfacial stresses of a steel beam strengthened by the FRP plate with taper model, taking into account a new coupled approach of prestressing force and hygrothermal effect. This article explores the effects of various parameters, such as geometrical and physical properties, on the stress behavior of FRP composites.

scholarly journals Studying the influence of the cross section height on the distribution of the internal efforts of wooden glued beams

2019 ◽  
Vol 135 ◽  
pp. 03048
Author(s):  
Sergei Prokhorov
Keyword(s):  
Cross Section ◽  
High Strength ◽  
Large Error ◽  
Environmental Friendliness ◽  
High Rise ◽  
Reinforced Beams ◽  
Flexural Member ◽  
Strength And Stiffness ◽  
Capital Construction ◽  
Wooden Structures

Since ancient times, wooden structures have been used by man for the construction of buildings and facilities. For many centuries, the structural elements of buildings and facilities made of wood have been the main ones, and still have broad prospects for use in modern capital construction, as they have sufficient high strength and stiffness, are reliable and durable, while having a small mounting weight. In particular, a number of Western countries are already erecting high-rise buildings using a framework of laminated wood constructions. The indisputable advantage of wooden structures is environmental friendliness. However, with all the harmony of the wood structure, its tracheid’s are not standard, which is the main reason for the variability of its mechanical properties. With alteration of a cross-section of flexural member, the nature of the load distribution, as well as the nature of the fracture, changes. An additional factor that affecting the force distribution is the nature of the reinforcement and methods of the reinforcement fixing methods. The methods used to calculate the “low” reinforced beams often give a large error in the calculation of “high” beams. In the work, a rational methodology for calculating wooden glued reinforced beams with symmetrical reinforcement is determined.

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