scholarly journals Natural Silkworm Cocoon Composites with High Strength and Stiffness Constructed in Confined Cocooning Space

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1214 ◽  
Author(s):  
Lan Cheng ◽  
Xiaoling Tong ◽  
Zhi Li ◽  
Zulan Liu ◽  
Huiming Huang ◽  
...  
Keyword(s):  
High Performance ◽  
High Strength ◽  
Homogeneous Layer ◽  
Dense Layer ◽  
Test Results ◽  
Young’S Moduli ◽  
Layer Structures ◽  
Potential Applications ◽  
Silkworm Cocoon ◽  
Strength And Stiffness

In this study, using round paper tubes (PTs) and rectangular cardboard boxes (CBs) as external constraints to control the size of the cocooning space, we fabricated a series of modified silkworm cocoons (PT cocoons and CB cocoons). Their microstructures, morphologies, compositions, and mechanical properties were characterized and compared with normal silkworm cocoons. These two kinds of modified silkworm cocoons exhibit dense and homogeneous layer structures. Tensile test results indicate that above a size limit of cocooning space, their tensile strengths, Young’s moduli, and strain energy densities increase with the decrease in cocooning space. Especially in comparison with the normal cocoons, the tensile strength and Young’s modulus of the PT-14 cocoon increase by 44% and 100%, respectively. Meanwhile, PT cocoons and CB cocoons, except PT-12, also possess better peeling resistance than normal cocoons. Owing to the dense structure and low porosity, the modified cocoons form robust fiber networks that result in high strength and toughness. This study provides a green and efficient method to fabricate mechanically enhanced silkworm cocoons with special shapes and dense layer structures. The method can be easily subjected to further modification processes and has potential applications in the production of high-performance green cocoon composites and biomimetic materials.

Forming Potential of Steel/Polymer/Steel Sandwich Composites with Local Plate Inserts

2012 ◽  
Vol 706-709 ◽  
pp. 681-686 ◽  
Author(s):  
Heinz Palkowski ◽  
Olga Sokolova ◽  
Adele Carradò
Keyword(s):  
Deep Drawing ◽  
High Performance ◽  
High Strength ◽  
Metal Plate ◽  
Elastic Behaviour ◽  
Forming Limit ◽  
Sandwich Composites ◽  
Strength And Stiffness ◽  
Naval Engineering ◽  
Forming Behaviour

High-performance metal/polymer/metal hybrid sandwich composites are attractive materials for lightweight constructions in automotive, aerospace and naval engineering world-wide. Due to the excellent combination of mechanical, thermal and elastic properties and, as a result of high forming potential, they can be used in areas of high vibration, where high damping properties of the polymer are demanded and at the same time high strength and stiffness are given by the metal. Disadvantages can be given in case of mechanical or thermal joining of these polymer-based sandwiches because of the elastic behaviour as well as low melting temperature of the polymer. Local metal plate insertions in the soft core at the place of joining can be a solution for such kind of problems. But forming behaviour of sandwich materials with and without local inlays differs strongly. Sandwich composites of that type were produced by roll-bonding. Their quality and their position were controlled by Lockin thermography. The forming behaviour of sandwiches with different geometry, size, type and the position of the inlays was tested by deep drawing and bending and analysed with the help of digital photogrammetry and compared to experimentally obtained mechanical properties. As a result, the local inlays, as well as their geometry, size and type strongly influence the forming limit conditions. The differences in flow behaviour of non-reinforced and reinforced sandwich regions after deep drawing and bending will be presented, as well as the influence of the position of the inlays.

scholarly journals Lightweight in Automotive Components by Forming Technology

2020 ◽  
Vol 3 (3) ◽  
pp. 195-209 ◽  
Author(s):  
Stephan Rosenthal ◽  
Fabian Maaß ◽  
Mike Kamaliev ◽  
Marlon Hahn ◽  
Soeren Gies ◽  
...  
Keyword(s):  
High Performance ◽  
Lightweight Design ◽  
Dissimilar Materials ◽  
Hot Extrusion ◽  
High Strength ◽  
Extrusion Process ◽  
Specific Strength ◽  
Metal Metal ◽  
Fiber Metal ◽  
Strength And Stiffness

AbstractLightweight design is one of the current key drivers to reduce the energy consumption of vehicles. Design methodologies for lightweight components, strategies utilizing materials with favorable specific properties and hybrid materials are used to increase the performance of parts for automotive applications. In this paper, various forming processes to produce light parts are described. Material lightweight design is discussed, covering the manufacturing processes to produce hybrid components like fiber–metal, polymer–metal and metal–metal composites, which can be used in subsequent deep drawing or combined forming processes. Approaches to increasing the specific strength and stiffness with thermomechanical forming processes as well as the in situ control of the microstructure of such components are presented. Structure lightweight design discusses possibilities to plastically form high-strength or high-performance materials like magnesium or titanium in sheet, profile and tube forming operations. To join those materials and/or dissimilar materials, new joining by forming technologies are shown. To economically produce lightweight parts with gears or functional elements, incremental sheet-bulk metal forming is presented. As an important part property, the damage evolution during the forming operations will be discussed to enable even lighter parts through a more reliable design. New methods for predicting and tailoring the mechanical properties like strength and residual stresses will be shown. The possibilities of system lightweight design with forming technologies are presented. A combination of additive manufacturing and forming to produce highly complex parts with integrated functions will be shown. The integration of functions by a hot extrusion process for the manufacturing of shape memory alloys is presented. An in-depth understanding of the newly developed processes, methodologies and effects allows for a more accurate dimensioning of components. This facilitates a reduction in the total mass and an increasing performance of vehicle components.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

High-Performance Polymer Fibers

MRS Bulletin ◽  
1987 ◽  
Vol 12 (8) ◽  
pp. 22-26 ◽  
Author(s):  
W. Wade Adams ◽  
R. K. Eby
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Covalent Bond ◽  
High Strength ◽  
Aromatic Polyamide ◽  
Chain Molecules ◽  
Ordered Array ◽  
New Ideas ◽  
Strong Motivation ◽  
Strength And Stiffness

Since the pioneering work of Carothers which led to the introduction of strong nylon fibers by DuPont in the 1930s, polymer scientists have pursued the development of high-performance fibers to replace natural or metallic products, both to improve mechanical properties and to reduce weight. That development was relatively slow and evenly paced until DuPont again revolutionized the field with the release of Kevlar™, an aromatic polyamide with unprecedented mechanical properties. Since then, the field has literally boomed with new developments, and now organic fibers are available with properties that compete with the best inorganics and are far superior to metal fibers.Strong motivation for the invention of new organic fibers comes from the aerospace industry, which seeks fibers to use in reinforced composite structural materials. Composites bring new advances in stiffness (airplane wings can't bend too much!) in weight savings (every kilogram saved in the structure of an airplane saves $120 over its lifetime, and in a spacecraft $10,000), and in radically new ideas, such as radar-invisibility (stealth)5 and mission-adaptive wings (in-flight variable-shape wings). Hence, for a variety of specialty applications, otherwise commercially indefensible materials become viable.It may be somewhat counter intuitive to materials scientists unfamiliar with polymers to expect polymer mechanical properties to be greater than in the best metals. The origin of high strength and stiffness in a polymer fiber is the covalent bond, especially when aligned in an ordered array of long chain molecules.

Confined capping system for compressive strength testing of high performance concrete cylinders

1995 ◽  
Vol 22 (3) ◽  
pp. 617-620 ◽  
Author(s):  
Claude D. Johnson ◽  
S. Ali Mirza
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Concrete Specimen ◽  
Strength Testing ◽  
Test Results ◽  
Testing Procedures ◽  
Testing Method ◽  
Concrete Cylinders

This paper presents a simple, inexpensive confined cap testing method which can be employed in the compressive strength testing of high performance concrete cylinders. An inexpensive customized cylinder capping apparatus and standard concrete laboratory testing equipment are employed. The paper describes the capping apparatus, capping and testing procedures, as well as test results for concrete compressive strengths up to and exceeding 100 MPa. Key words: capping, capping confinement, compressive strength, cylinders, end condition, grinding, high-strength concrete, specimen size, testing.

Influence of Metakaolin on Mechanical Properties of High-Performance Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1904-1909
Author(s):  
Bao Min Wang ◽  
Wei Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Equal Mass ◽  
Test Results ◽  
Optimum Temperature ◽  
Compressive Strength Of Concrete ◽  
And Performance

Kaolin is a material with broad sources and a low price. Metakaolin is made from kaolin which is calcined, finely ground at an optimum temperature of 750 being kept constant for 4 hours. High strength and performance concrete can be mixed from metakaolin as a substitute for equal mass cement. The influences of 5%, 10% and 15% metakaolin in substitution of equal cement masses were studied on the mechanical properties of high-performance concrete. The test results showed that the addition of metakaolin improved the cubic compressive strength, splitting tensile strength and flexural strength of HPC, among which the improvement in compressive strength was the most siginificant, and simultaneously, there was also an improvement in concrete toughness in a certain degree. The optimum content of metakaolin is 10% resulting in an increase of the cubic compressive strength of concrete by 8.3% correspondingly.

scholarly journals Microbial production of megadalton titin yields fibers with advantageous mechanical properties

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher H. Bowen ◽  
Cameron J. Sargent ◽  
Ao Wang ◽  
Yaguang Zhu ◽  
Xinyuan Chang ◽  
...  
Keyword(s):  
Small Molecules ◽  
High Performance ◽  
Polymeric Materials ◽  
High Strength ◽  
Microbial Production ◽  
Damping Capacity ◽  
Natural Polymers ◽  
Potential Applications ◽  
Chain Slippage ◽  
Synthetic And Natural Polymers

AbstractManmade high-performance polymers are typically non-biodegradable and derived from petroleum feedstock through energy intensive processes involving toxic solvents and byproducts. While engineered microbes have been used for renewable production of many small molecules, direct microbial synthesis of high-performance polymeric materials remains a major challenge. Here we engineer microbial production of megadalton muscle titin polymers yielding high-performance fibers that not only recapture highly desirable properties of natural titin (i.e., high damping capacity and mechanical recovery) but also exhibit high strength, toughness, and damping energy — outperforming many synthetic and natural polymers. Structural analyses and molecular modeling suggest these properties derive from unique inter-chain crystallization of folded immunoglobulin-like domains that resists inter-chain slippage while permitting intra-chain unfolding. These fibers have potential applications in areas from biomedicine to textiles, and the developed approach, coupled with the structure-function insights, promises to accelerate further innovation in microbial production of high-performance materials.

Chemical Durability Investigation of Magnesium Phosphosilicate Cement

2006 ◽  
Vol 302-303 ◽  
pp. 275-281 ◽  
Author(s):  
Zhu Ding ◽  
Zong Jin Li ◽  
Feng Xing
Keyword(s):  
Portland Cement ◽  
High Performance ◽  
Sea Water ◽  
High Strength ◽  
Chemical Durability ◽  
Test Results ◽  
Chemical Corrosion ◽  
The Sustainable Development ◽  
Parallel Tests ◽  
Chemical Corrosion Resistance

The magnesium phosphosilicate cement (MPSC) is a novel inorganic binder, it sets quickly and has very high strength. Also, it is a promising material for the sustainable development. In the present study, the durability of MPSC were investigated, including deicer scaling resistance under freezing-thawing cycles, chemical corrosion resistance in sodium sulfate and magnesium sulfate solutions, and wet-dry resistance in fresh and natural sea water. For comparison, Portland cement samples were also prepared for parallel tests. Test results showed that the chemical durability of MPSC is superior that of Portland cement. The causes of the high performance may be attributed to the low water demand and a reasonable microstructure of hardened paste matrix.

Cellulose microfibrils: A novel method of preparation using high shear refining and cryocrushing

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Ayan Chakraborty ◽  
Mohini Sain ◽  
Mark Kortschot
Keyword(s):  
High Performance ◽  
High Strength ◽  
Cellulose Microfibrils ◽  
Laser Confocal Microscopy ◽  
Novel Technique ◽  
Freeze Dried ◽  
Mechanical Methods ◽  
Novel Method ◽  
Impact Crushing ◽  
Strength And Stiffness

Abstract This paper describes a novel technique to produce cellulose microfibrils through mechanical methods. The technique involved a combination of severe shearing in a refiner, followed by high-impact crushing under liquid nitrogen. Fibers treated in this way were subsequently either freeze-dried or suspended in water. The fibers were characterized using SEM, TEM, AFM, and high-resolution optical microscopy. In the freeze-dried batch, 75% of the fibrils had diameters of 1 μm and below, whereas in the water dispersed batch, 89% of the fibrils had diameters in this range. The aspect ratio of the microfibrils ranged between 15 and 55 for the freeze-dried fibrils, and from 20 to 85 for the fibrils dispersed in water. These measurements suggest that the microfibrils have the potential to produce composites with high strength and stiffness for high-performance applications. The microfibrils in water were compounded with polylactic acid polymer to form a biocomposite. Laser confocal microscopy showed that the microfibrils were well dispersed in the polymer matrix.

scholarly journals Mechanical and Static Stab Resistant Properties of Hybrid-Fabric Fibrous Planks: Manufacturing Process of Nonwoven Fabrics Made of Recycled Fibers

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1140 ◽  
Author(s):  
Yu-Chun Chuang ◽  
Limin Bao ◽  
Mei-Chen Lin ◽  
Ching-Wen Lou ◽  
TingAn Lin
Keyword(s):  
High Performance ◽  
High Strength ◽  
Woven Fabrics ◽  
Test Results ◽  
High Modulus ◽  
New Materials ◽  
Nonwoven Fabrics ◽  
Pet Fibers ◽  
Recycled Fibers ◽  
Hybrid Fabric

With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also need to be replaced. This study proposes a highly efficient recycling and manufacturing design to create more added values for the waste materials. With a premise of minimized damage to fibers, the recycled selvage made of high strength PET fibers are reclaimed to yield high performance staple fibers at a low production cost. A large amount of recycled fibers are made into matrices with an attempt to decrease the consumption of new materials, while the combination of diverse plain woven fabrics reinforces hybrid-fabric fibrous planks. First, with the aid of machines, recycled high strength PET fibers are processed into staple fibers. Using a nonwoven process, low melting point polyester (LMPET) fibers and PET staple fibers are made into PET matrices. Next, the matrices and different woven fabrics are combined in order to form hybrid-fabric fibrous planks. The test results indicate that both of the PET matrices and fibrous planks have good mechanical properties. In particular, the fibrous planks yield diverse stab resistances from nonwoven and woven fabrics, and thus have greater stab performance.

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