A Sequential Two-Step Design Framework for Deformable Mechanical Metamaterials

2020 ◽  
Author(s):  
Sree Kalyan Patiballa ◽  
Girish Krishnan
Keyword(s):  
Shape Change ◽  
Building Blocks ◽  
Load Flow ◽  
Stretchable Electronics ◽  
Design Framework ◽  
Shape Morphing ◽  
Mechanical Metamaterials ◽  
Global Deformation ◽  
Deformation Patterns

Abstract Deformable metamaterials are materials that are made up of several repeating elastic building blocks whose geometries can be tailored to obtain a specified global shape change or stiffness behavior. They are deemed useful in soft robotics, shape morphing mechanisms, stretchable electronics, wearable devices, and devices that adapt according to their environment. This paper presents a two-step sequential design framework for the synthesis of deformable mechanical metamaterials where (a) topology optimization is used to map global deformation requirement to local elasticity matrix, followed by (b) a selection of building block microstructure geometry from a database and refining it to match the elasticity requirement. The first step is accomplished through a unique parameterization scheme that enables the classification of the planar orthotropic elasticity matrix into four distinct classes. The second step uses a kinetostatic framework known as load flow visualization to populate candidate microstructure geometries within these four classes. Finally, the framework is validated for the design of a cantilever beam with a specified lateral stiffness requirement and the design of planar sheets that exhibit sinusoidal deformation patterns.

Topological classification of periodic orbits in the Kuramoto–Sivashinsky equation

2018 ◽  
Vol 32 (15) ◽  
pp. 1850155 ◽  
Author(s):  
Chengwei Dong
Keyword(s):  
Nonlinear System ◽  
Variational Method ◽  
Periodic Orbits ◽  
Symbolic Dynamics ◽  
Chaotic Systems ◽  
Building Blocks ◽  
Topological Classification ◽  
One Dimensional ◽  
Sivashinsky Equation

In this paper, we systematically research periodic orbits of the Kuramoto–Sivashinsky equation (KSe). In order to overcome the difficulties in the establishment of one-dimensional symbolic dynamics in the nonlinear system, two basic periodic orbits can be used as basic building blocks to initialize cycle searching, and we use the variational method to numerically determine all the periodic orbits under parameter [Formula: see text] = 0.02991. The symbolic dynamics based on trajectory topology are very successful for classifying all short periodic orbits in the KSe. The current research can be conveniently adapted to the identification and classification of periodic orbits in other chaotic systems.

scholarly journals Divergent Design of Mechanical Metamaterials Clan Deducted from Arc-serpentine Curve

2021 ◽  
Author(s):  
Shengli Mi ◽  
Hongyi Yao ◽  
Xiaoyu Zhao ◽  
Wei Sun
Keyword(s):  
Thick Plate ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Design Strategies ◽  
Shape Morphing ◽  
Mechanical Metamaterials ◽  
Unit Cells ◽  
Combinatorial Principles ◽  
Composite Curve ◽  
Typical Design

Abstract The exotic properties of mechanical metamaterials are determined by their unit-cells' structure and spatial arrangement, in analogy with the atoms of conventional materials. Companioned with the mechanism of structural or cellular materials1–5, the ancient wisdom of origami6–11 and kirigami12–16 and the involvement of multiphysics interaction2,17,18 enrich the programable mechanical behaviors of metamaterials, including shape-morphing8,12,14,16,19, compliance4,5,8,17,20, texture2,18,21, and topology11,18,22−25. However, typical design strategies are mainly convergent, which transfers various structures into one family of metamaterials that are relatively incompatible with the others and do not fully bring combinatorial principles3,10,26 into play. Here, we report a divergent strategy that designs a clan of mechanical metamaterials with diverse properties derived from a symmetric curve consisting of serpentines and arcs. We derived this composite curve into planar and cubic unit-cells and modularized them by attaching magnetics. Moreover, stacking each of them yields two- and three-dimensional auxetic metamaterials, respectively. Assembling with both modules, we achieved three thick plate-like metamaterials separately with flexibility, in-plane buckling, and foldability. Furthermore, we demonstrated that the hybrid of paradox properties is possible by combining two of the above assembles. We anticipate that this divergent strategy paves the path of building a hierarchical library of diverse combinable mechanical metamaterials and making conventional convergent strategies more efficient to various requests. Main

Shape-Morphing Mechanical Metamaterials

2021 ◽  
pp. 103146
Author(s):  
Caigui Jiang ◽  
Florian Rist ◽  
Hui Wang ◽  
Johannes Wallner ◽  
Helmut Pottmann
Keyword(s):  
Shape Morphing ◽  
Mechanical Metamaterials

Containers and Connectors as Elements in a Portal Design Framework

2012 ◽  
pp. 223-244
Author(s):  
Joe Lamantia
Keyword(s):  
Best Practices ◽  
Building Blocks ◽  
Design Framework ◽  
Simple Rules

This article defines the standardized elements used in the building blocks portal design framework in detail, as the second in a series of articles on a Portal Design Framework. This article explains the (simple) rules and relationships for combining Containers and Connectors into portal structures. This article shares best practices, examples, and guidelines for effectively using the building blocks framework during portal design efforts.

Enhancing the Portal Experience

2010 ◽  
Vol 2 (2) ◽  
pp. 12-25 ◽  
Author(s):  
Joe Lamantia
Keyword(s):  
Best Practices ◽  
User Experience ◽  
Building Blocks ◽  
Business Practices ◽  
Design Framework ◽  
Enterprise 2.0 ◽  
Social Business ◽  
The Third ◽  
User Value

This article presents strategies for enhancing the long-term business and user value of portals as the third in a series of articles describing a Portal Design Framework. This article identifies essential Enterprise 2.0 functionality for collaboration and dialog—capabilities that support emerging Social Business practices—included in the Building Blocks Design Framework. The author discusses portal management and governance best practices and describes strategies for maintaining and enhancing the user experience of portals designed using the Building Blocks Framework.

Using the Building Blocks

2010 ◽  
Vol 2 (3) ◽  
pp. 43-55
Author(s):  
Joe Lamantia
Keyword(s):  
Building Blocks ◽  
Design Framework ◽  
Design And Development ◽  
Over Time

This article is a case study that explores the use of the Building Blocks portal design framework over a series of enterprise portal projects spanning several years. This article describes the business contexts that shaped each portal as it was designed, showing the use and reuse of design and development elements based on the Building Blocks. This article discusses the changes and adaptations that shaped the elements of the Building Blocks design framework over time.

Load-Transmitter Constraint Sets: Part II—A Building Block Based Methodology for the Synthesis of Compliant Mechanisms

2010 ◽  
Author(s):  
Girish Krishnan ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Compliant Mechanisms ◽  
Load Flow ◽  
Flow Path ◽  
Mathematical Representation ◽  
Mathematical Framework ◽  
Systematic Design ◽  
Shape Morphing ◽  
Load Paths ◽  
Block Based ◽  
Extensive Computation

Designers have always conceptualized of load flow as a part of their initial design process for mechanisms and structures. However, the lack of mathematical representation of load flow makes it inappropriate to be included in systematic design processes. Load Transmitter Constraint (LTC) sets provide a mathematical framework for visualizing load paths in compliant mechanisms. In this paper we propose a systematic design methodology for compliant mechanisms by systematic combination of LTC sets. This enables the designer to conceptualize load flow and choose relevant LTC sets to enforce it. Apart from being intuitive this process gives an understanding of the importance of each member in the mechanism. Furthermore this theory enables accurate and deterministic design for given motion specification without the aid of extensive computation. In this paper we propose guidelines for the design of mechanisms with a single load flow path and multi load flow path, particularly relevant in shape morphing applications.

Posable Tensegrity-Constrained Inflatable Kinematic Graphical Analysis

2020 ◽  
Author(s):  
Adeline Wihardja ◽  
Kunj Patel ◽  
Laura Giner Munoz ◽  
Ellen Kim ◽  
Jonathan Luntz ◽  
...  
Keyword(s):  
Kinematic Analysis ◽  
Shape Change ◽  
Low Cost ◽  
Building Blocks ◽  
Pressure Control ◽  
Graphical Analysis ◽  
Three Dimensions ◽  
Analysis And Design ◽  
Novel Technology ◽  
Instantaneous Center

Abstract Inflatable devices have been used in various applications due to their low cost, light weight, simplicity, and ability to compactly stow yet deploy to large sizes with complex shape. Recently, soft robotics has added active shape change to inflatables’ otherwise static functionality. However, the required complex multi-chamber structures and active pressure control sacrifice many inherent advantages including simplicity and stowability. Many applications require only passive shape change (posability), where users manipulate a device manually, and the device simply holds its new posed shape. This paper explores a new approach using internal string-like tensile elements to provide posability while maintaining stowability and other inherent advantages of inflatables, leveraging concepts in the field of tensegrity mechanisms. Tensegrity constrained inflatables provide posable motion by allowing internal tensile strings to thread through loops as the shape is changed, where friction between the strings and loops retain the new pose. Graphical instantaneous center kinematic analysis techniques for traditional linkage systems are extended to include threaded tensegrity mechanisms, enabling analysis and design of complex posable tensegrity structures. A simple example prototype implementing bending with 1 DOF, demonstrates posable behavior, quantified in terms of the force required to change pose at different angles and pressures. The resulting bistable behavior is explained using the IC kinematic analysis. The kinematic techniques are also applied to the design of one degree of freedom functional building blocks which combine to create tensegrity configurations providing 2 DOF posability in two and three dimensions which are demonstrated through multiple hardware prototypes. The novel technology and design methods presented in this paper provide a foundation for the development of a class of new user-interactive inflatable devices with posable functionality and deploy and stow capability.

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