Topological Interlocking in Design of Structures and Materials

2009 ◽  
Vol 1188 ◽  
Author(s):  
Yuri Estrin ◽  
Arcady Dyskin ◽  
Elena Pasternak ◽  
Stephan Schaare
Keyword(s):  
Mechanical Properties ◽  
Experimental Evidence ◽  
Fracture Resistance ◽  
Building Blocks ◽  
Research Groups ◽  
Engineering Applications ◽  
Topological Interlocking ◽  
Novel Structures ◽  
Promising Avenue

AbstractSince its introduction in 2001 [1], the concept of topological interlocking has advanced to reasonable maturity, and various research groups have now adopted it as a promising avenue for developing novel structures and materials with unusual mechanical properties. In this paper, we review the known geometries of building blocks and their arrangements that permit topological interlocking. Their properties relating to stiffness, fracture resistance and damping are discussed on the basis of experimental evidence and modeling results. An outlook to prospective engineering applications is also given.

scholarly journals PyroMEMS as Future Technological Building Blocks for Advanced Microenergetic Systems

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Jean-Laurent Pouchairet ◽  
Carole Rossi
Keyword(s):  
Building Block ◽  
Building Blocks ◽  
Small Scale ◽  
Technological Evolution ◽  
Research Groups ◽  
Function Block ◽  
The Past ◽  
New Methods ◽  
Safety And Reliability ◽  
Electronically Controllable

For the past two decades, many research groups have investigated new methods for reducing the size and cost of safe and arm-fire systems, while also improving their safety and reliability, through batch processing. Simultaneously, micro- and nanotechnology advancements regarding nanothermite materials have enabled the production of a key technological building block: pyrotechnical microsystems (pyroMEMS). This building block simply consists of microscale electric initiators with a thin thermite layer as the ignition charge. This microscale to millimeter-scale addressable pyroMEMS enables the integration of intelligence into centimeter-scale pyrotechnical systems. To illustrate this technological evolution, we hereby present the development of a smart infrared (IR) electronically controllable flare consisting of three distinct components: (1) a controllable pyrotechnical ejection block comprising three independently addressable small-scale propellers, all integrated into a one-piece molded and interconnected device, (2) a terminal function block comprising a structured IR pyrotechnical loaf coupled with a microinitiation stage integrating low-energy addressable pyroMEMS, and (3) a connected, autonomous, STANAG 4187 compliant, electronic sensor arming and firing block.

scholarly journals Bacterial cellulose spheroids as building blocks for 3D and patterned living materials and for regeneration

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joaquin Caro-Astorga ◽  
Kenneth T. Walker ◽  
Natalia Herrera ◽  
Koon-Yang Lee ◽  
Tom Ellis
Keyword(s):  
Bacterial Cellulose ◽  
Building Blocks ◽  
Genetically Engineered ◽  
High Yield ◽  
Synthetic Materials ◽  
Chemical Inputs ◽  
First Time ◽  
3D Shapes ◽  
Promising Avenue ◽  
Living Materials

AbstractEngineered living materials (ELMs) based on bacterial cellulose (BC) offer a promising avenue for cheap-to-produce materials that can be programmed with genetically encoded functionalities. Here we explore how ELMs can be fabricated in a modular fashion from millimetre-scale biofilm spheroids grown from shaking cultures of Komagataeibacter rhaeticus. Here we define a reproducible protocol to produce BC spheroids with the high yield bacterial cellulose producer K. rhaeticus and demonstrate for the first time their potential for their use as building blocks to grow ELMs in 3D shapes. Using genetically engineered K. rhaeticus, we produce functionalized BC spheroids and use these to make and grow patterned BC-based ELMs that signal within a material and can sense and report on chemical inputs. We also investigate the use of BC spheroids as a method to regenerate damaged BC materials and as a way to fuse together smaller material sections of cellulose and synthetic materials into a larger piece. This work improves our understanding of BC spheroid formation and showcases their great potential for fabricating, patterning and repairing ELMs based on the promising biomaterial of bacterial cellulose.

Synthesis and characterization of poly(glycerol sebacate)-based elastomeric copolyesters for tissue engineering applications

2016 ◽  
Vol 7 (14) ◽  
pp. 2553-2564 ◽  
Author(s):  
Yating Jia ◽  
Weizhong Wang ◽  
Xiaojun Zhou ◽  
Wei Nie ◽  
Liang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Water Uptake ◽  
Synthesis And Characterization ◽  
Uptake Capacity ◽  
Engineering Applications ◽  
Water Uptake Capacity

A poly(glycerol sebacate)-based elastomeric copolyesters with improved mechanical properties and higher water uptake capacity.

scholarly journals Review on the Influence of Temperature upon Hydrogen Effects in Structural Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 423
Author(s):  
Thorsten Michler ◽  
Frank Schweizer ◽  
Ken Wackermann
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Temperature Effect ◽  
Statistical Approach ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Effect Of Temperature ◽  
Engineering Applications ◽  
Selection For ◽  
Typical Temperature

It is well-documented experimentally that the influence of hydrogen on the mechanical properties of structural alloys like austenitic stainless steels, nickel superalloys, and carbon steels strongly depends on temperature. A typical curve plotting any hydrogen-affected mechanical property as a function of temperature gives a temperature THE,max, where the degradation of this mechanical property reaches a maximum. Above and below this temperature, the degradation is less. Unfortunately, the underlying physico-mechanical mechanisms are not currently understood to the level of detail required to explain such temperature effects. Though this temperature effect is important to understand in the context of engineering applications, studies to explain or even predict the effect of temperature upon the mechanical properties of structural alloys could not be identified. The available experimental data are scattered significantly, and clear trends as a function of chemistry or microstructure are difficult to see. Reported values for THE,max are in the range of about 200–340 K, which covers the typical temperature range for the design of structural components of about 230–310 K (from −40 to +40 °C). That is, the value of THE,max itself, as well as the slope of the gradient, might affect the materials selection for a dedicated application. Given the current lack of scientific understanding, a statistical approach appears to be a suitable way to account for the temperature effect in engineering applications. This study reviews the effect of temperature upon hydrogen effects in structural alloys and proposes recommendations for test temperatures for gaseous hydrogen applications.

Core-modified porphyrins: novel building blocks in chemistry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksey E. Kuznetsov
Keyword(s):  
Periodic Table ◽  
Building Blocks ◽  
Effective Strategy ◽  
Research Groups ◽  
Structures And Properties ◽  
Porphyrin Core ◽  
Living Organisms ◽  
New Compounds ◽  
Related Compounds ◽  
Nitrogen Phosphorus

Abstract Various (metallo)porphyrins and related compounds have been intensively investigated by different research groups due to their extremely important role in living organisms along with their versatile applications in technology. The design of novel porphyrinoids by core-modification, or substitution of pyrrole nitrogens, with the elements of other groups of the Periodic Table has been considered as a highly promising methodology for tuning structures and properties of porphyrinoids and thus opening new possible applications for them. Much effort has been given to the modifications of the porphyrin core with elements of the main groups, namely O, S, Se (chalcogens), and the heavier congener of nitrogen, phosphorus. In general, the porphyrin core modification by replacing nitrogens with heteroatoms is a promising and effective strategy for obtaining new compounds with unusual structures and properties (optical, electrochemical, coordinating, etc.) as well as reactivity. These novel molecules can also be employed as promising building or construction blocks in various applications in the nanotechnology area.

Effect of Filler Compositions on the Mechanical Properties of Bamboo Filled Polyester Composite

2014 ◽  
Vol 879 ◽  
pp. 90-95 ◽  
Author(s):  
Abdul Rahman Noor Leha ◽  
Nor Amalina Nordin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Impact Test ◽  
Compression Molding ◽  
Engineering Applications ◽  
Maximum Value ◽  
Polyester Composite ◽  
Bamboo Powder ◽  
Flexural Tests ◽  
The Impact

Biocomposite from bamboo powder was fabricated by compression molding technique. The objective of this study was to investigate the mechanical properties of bamboo compounded with epoxy with different ratio. Tensile and flexural tests were done to characterize its mechanical properties. It was observed that the strength of bamboo-polyester was increased with increasing amount of bamboo powder. The tensile and flexural strength shows the highest value at 25 wt.% bamboo. However, the impact test shows the maximum value at 20 wt.% bamboo powder. These results exhibit the bamboo-polyester can be a good candidate to be used in many engineering applications

scholarly journals Experimental Study on Mixed Mode Fracture Behavior of Sandstone under Water–Rock Interactions

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 70 ◽  
Author(s):  
Wen Hua ◽  
Jianxiong Li ◽  
Shiming Dong ◽  
Xin Pan
Keyword(s):  
Mechanical Properties ◽  
Fracture Resistance ◽  
Mixed Mode ◽  
Degradation Mechanism ◽  
Mixed Mode Fracture ◽  
Pure Mode ◽  
Brazilian Disk ◽  
Tangential Strain ◽  
Mode Fracture

Water–rock interactions can significantly deteriorate the physical and mechanical properties of rocks, and it has been identified as one of the significant factors influencing the stability and safety of structures in rock–soil engineering. In this study, the fracture mechanical properties of sandstone under periodic water–rock interactions and long-term immersion have been studied with central cracked Brazilian disk specimens. The degradation mechanism of water–rock interactions was also studied using a scanning electron microscope (SEM). Finally, the generalized maximum tangential stress and generalized maximum tangential strain criteria were adopted to evaluate the experimental results. The results show that periodic water–rock interactions can remarkably affect the fracture resistance of sandstone. With the increase in the number of cycles, the pure mode I, pure mode II, and mixed mode fracture toughness decreases greatly, however, the values of KIf/KIC and KIIf/KIC decrease slightly. Furthermore, the fracture resistance of sandstone influenced by cyclic wetting–drying is more significant than long-term immersion. Moreover, the fracture criteria, which considers the effect of T-stress, can reproduce the test results very well.

Physical Properties of Building Blocks from Hemp Shives Aggregate and Cementitious Binder, Manufactured in the Expanded Clay (Vibro Pressing) Production Line

2017 ◽  
Vol 908 ◽  
pp. 118-122 ◽  
Author(s):  
Giedrius Balčiūnas ◽  
Viktor Kizinievič ◽  
Justinas Gargasas
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Physical Properties ◽  
Production Line ◽  
Scientific Literature ◽  
Building Blocks ◽  
Freeze Thaw ◽  
Cementitious Binder ◽  
Pressing Technology

Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) aggregate and lime binder, although, such materials are characterised by pretty low mechanical properties. In order to obtain higher mechanical properties of a composite, it is appropriate to use cementitious binder. This work investigates physical properties of blocks from hemp shives aggregate and cementitious binder, manufactured in the expanded clay production line using vibro pressing technology. Following properties of the blocks are determined: freeze-thaw resistance, compressive strength, thermal conductivity and density. Thermal resistance according to EN ISO 6946 for the block with cavities is calculated as well. It is found that compressive strength of FHS-cement blocks may be up to 3.18 MPa when the density is of ~850 kg/m3 and thermal conductivity up to 0.135 W/(m∙K). It is found as well that the decrease of compressive strength is 8.7% after 25 freeze-thaw cycles.

EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF MAGNETORHEOLOGICAL ELASTOMER

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Nurul Husna Rajhan ◽  
Hanizah Ab. Hamid ◽  
Azmi Ibrahim ◽  
Rozaina Ismail
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Strength ◽  
Carbon Black ◽  
Tensile Test ◽  
Magnetorheological Elastomer ◽  
Dead Load ◽  
Carbon Black Content ◽  
Engineering Applications ◽  
Magnetorheological Elastomers

Magnetorheological elastomers (MREs) have much interest in engineering applications. However, the mechanical properties of MREs are still under ongoing researches. This paper presents the results from tensile test, hardness and rebound test that were carried out in order to understand the mechanical properties of MRE with the influence of carbon black content. The addition of carbon black was varied with the amount of 20 pphr, 40 pphr and 60 pphr of carbon black. The development of the MRE composites was manufactured by following the conventional rubber compounding process. The optimum cure of each MRE composite was determined by using a Rheometer 100. The mechanical properties through tensile test were obtained by using an Instron Tensile Machine, meanwhile hardness and resilience were carried out by using Wallace Dead Load Hardness and Dunlop Tripsometer, respectively. The results of tensile strength were not consistent with the addition of carbon black. In meantime, hardness value increases as the carbon black increases. The decreasing pattern of MRE resilience could be observed when the carbon black content increases.

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