Scaling, Growth, and Size Effects on the Mechanical Behavior of a Topologically Interlocking Material Based on Tetrahedra Elements

2019 ◽  
Vol 86 (11) ◽  
Author(s):  
M. Short ◽  
T. Siegmund
Keyword(s):  
Load Transfer ◽  
Building Blocks ◽  
Truss Structures ◽  
Material System ◽  
Internal Load ◽  
Deformation Response ◽  
Granular Crystals ◽  
Architectured Material ◽  
Topological Interlocking ◽  
System Characteristics

AbstractThe present study is concerned with the deformation response of an architectured material system, i.e., a 2D-material system created by the topological interlocking assembly of polyhedra. Following the analogy of granular crystals, the internal load transfer is considered along well-defined force networks, and internal equivalent truss structures are used to describe the deformation response. Closed-form relationships for stiffness, strength, and toughness of the topologically interlocked material system are presented. The model is validated relative to direct numerical simulation results. The topologically interlocked material system characteristics are compared with those of monolithic plates. The architectured material system outperforms equivalent size monolithic plates in terms of toughness for nearly all possible ratios of modulus to the strength of the material used to make the building blocks and plate, respectively. In addition, topologically interlocked material systems are shown to provide better strength characteristics than a monolithic system for low strength solids.

scholarly journals Mechanics of Tubes Composed of Interlocking Building Blocks

2022 ◽  
Author(s):  
Kyle Mahoney ◽  
Thomas Siegmund
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Building Blocks ◽  
Maximum Load ◽  
Finite Element Models ◽  
Element Analysis ◽  
Internal Load ◽  
Deformation Response ◽  
Good Agreement

Topologically interlocking material (TIM) systems are composed of convex polyhedral units placed such that building blocks restrict each other's movement. Here, TIM tubes are considered as rolled monolayers of such assemblies. The deformation response of these assembled tubes under diametrical loading is considered. This investigation employs experiments on additivelymanufactured physical realizations and finite element analysis with contact interactions. The internal load transfer in topologically interlocking tubes is rationalized through inspection of the distribution of minimum principalstress. A thrust-line (TL) model for the deformation of topologically interlocking tubes is established. The model approximates the deformation response of the assembled tubes as the response of a collection of Misestrusses aligned with paths of maximum load transfer in the system. The predictions obtained with the TL-model are in good agreement with results of finite element models. Accounting for sliding between building blocks in theTL-model yields a predicted response more similar to experimental results with additively manufactured tubes.

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 Exploring the Internal Radiative Efficiency of Selective Area Nanowires

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
A. Cavalli ◽  
J. E. M. Haverkort ◽  
E. P. A. M. Bakkers
Keyword(s):  
Solar Cell ◽  
High Growth ◽  
Optical Emission ◽  
Building Blocks ◽  
Growth Conditions ◽  
Material System ◽  
Solar Cell Application ◽  
Precise Control ◽  
Radiative Efficiency ◽  
Selective Area

Nanowires are ideal building blocks for next-generation solar cell applications. Nanowires grown with the selective area (SA) approach, in particular, have demonstrated very high material quality, thanks to high growth temperature, defect-free crystalline structure, and absence of external catalysts, especially in the InP material system. A comprehensive study on the influence of growth conditions and device processing on optical emission is still necessary though. This article presents an investigation of the nanowire optical properties, performed in order to optimize the internal radiative efficiency. In an initial preamble, the motivation for this study is discussed, as well as the morphology and crystallinity of the nanowires. The effect on the nanowire photoluminescence of several intrinsic and extrinsic parameters and factors are then presented in three sections: first, the influence of basic growth conditions such as the temperature and the precursor ratio is studied. Subsequently, the effects of varying dopant molar flows are explored, keeping in mind the intended solar cell application. Third, the manner in which the processing and the passivation affect the nanowire optical emission is discussed. Precise control of the growth conditions allows maximizing the nanowire internal radiative efficiency and thus their performance in solar cells and other optoelectronic devices.

Simulation-Based Design of a Self-Folding Smart Material System

2013 ◽  
Author(s):  
Edwin Peraza-Hernandez ◽  
Darren Hartl ◽  
Richard Malak
Keyword(s):  
Three Dimensional ◽  
Building Blocks ◽  
Passive Layer ◽  
Heating Power ◽  
Von Mises Stress ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Material System ◽  
Design Variables ◽  
Von Mises

Origami engineering — the practice of creating useful three-dimensional structures through folding operations on two-dimensional building-blocks — is receiving increased attention from the science, mathematics, and engineering communities. The topic of this paper is a new concept for a self-folding material system. It consists of an active, self-morphing laminate that includes two meshes of thermally-actuated shape memory alloy (SMA) separated by a compliant passive layer. The goal of this paper is to analyze several of the key engineering tradeoffs associated with the proposed self-folding material system. In particular, we examine how key design variables affect folding behavior in an SMA mesh-based folding sheet. The design parameters we consider in this study are wire thickness, mesh wire spacing, thickness of the insulating elastomer layer, and heating power. The output parameters are maximum von Mises stress in the SMA, maximum temperature in the SMA, and minimum folding angle. The results show that maximum temperature in the SMA is mostly dependent on the total heating power per unit width of SMA. The results also indicate that through-heating — heat transfer from one SMA layer to the other through the insulating elastomer — can impede folding for some physical configurations. However, we also find that one can mitigate this effect using a staggered mesh configuration in which the SMA wires on different layers are not aligned. Based on our results, we conclude that the new staggered mesh design can be effective in preventing unintended transformation of the non-actuated layer.

Internal load transfer in a metal matrix composite with a three-dimensional interpenetrating structure

2011 ◽  
Vol 59 (4) ◽  
pp. 1424-1435 ◽  
Author(s):  
S. Roy ◽  
J. Gibmeier ◽  
V. Kostov ◽  
K.A. Weidenmann ◽  
A. Nagel ◽  
...  
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Load Transfer ◽  
Three Dimensional ◽  
Internal Load

Internal load transfer and damage evolution in a 3D interpenetrating metal/ceramic composite

2012 ◽  
Vol 551 ◽  
pp. 272-279 ◽  
Author(s):  
Siddhartha Roy ◽  
Jens Gibmeier ◽  
Vladimir Kostov ◽  
Kay André Weidenmann ◽  
Alwin Nagel ◽  
...  
Keyword(s):  
Damage Evolution ◽  
Ceramic Composite ◽  
Load Transfer ◽  
Internal Load ◽  
Metal Ceramic

Investigation of the Effect of Rolling Bearing Construction on Internal Load Distribution and the Number of Active Rolling Elements

2013 ◽  
Vol 633 ◽  
pp. 103-116 ◽  
Author(s):  
Radoslav Tomovic
Keyword(s):  
Load Distribution ◽  
Load Transfer ◽  
Rolling Bearing ◽  
Radial Clearance ◽  
Radial Load ◽  
Rolling Bearings ◽  
Internal Load ◽  
Ring Support ◽  
Rolling Elements

One of the most important characteristics of a rolling bearing is the load distribution on rolling elements. This paper provides an analysis on the influence of the internal construction of rolling bearings on load distribution and the number of active rolling elements. The analysis was performed using a new mathematical model for the boundary level calculations of the bearing deflection and external radial load for the inner ring support onqrolling bearing elements. The model considers two boundary positions of inner ring support on an even and odd number of rolling elements. The developed model enables a very simple determination of the number of active rolling elements participating in an external load transfer, depending on the bearing type and internal radial clearance.

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