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Article
Publication date: 15 June 2010

Jonathan Hiller and Hod Lipson

Digital materials are composed of many discrete voxels placed in a massively parallel layer deposition process, as opposed to continuous (analog) deposition techniques…

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2217

Abstract

Purpose

Digital materials are composed of many discrete voxels placed in a massively parallel layer deposition process, as opposed to continuous (analog) deposition techniques. The purpose of this paper is to explore the wide range of material properties attainable using a voxel‐based freeform fabrication process, and demonstrate in simulation the versatility of fabricating with multiple materials in this manner.

Design/methodology/approach

A representative interlocking voxel geometry was selected, and a nonlinear physics simulator was implemented to perform virtual tensile tests on blocks of assembled voxels of varying materials. Surface contact between tiles, plastic deformation of the individual voxels, and varying manufacturing precision were all modeled.

Findings

By varying the precision, geometry, and material of the individual voxels, continuous control over the density, elastic modulus, coefficient of thermal expansion, ductility, and failure mode of the material is obtained. Also, the effects of several hierarchical voxel “microstructures” are demonstrated, resulting in interesting properties such as negative Poisson's ratio.

Research limitations/implications

This analysis is a case study of a specific voxel geometry, which is representative of 2.5D interlocking shapes but not necessarily all types of interlocking voxels.

Practical implications

The results imply that digital materials can exhibit widely varying and tunable properties in a single desktop fabrication process.

Originality/value

The paper explores the vast potential of tunable materials, especially using the concept of voxel microstructure, applicable primarily to 3D voxel printers but also to other multi‐material freeform fabrication processes.

Details

Rapid Prototyping Journal, vol. 16 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 22 February 2021

Devender Sheoran, Rajesh Kumar, Seema Thakran and Kapil Kumar Kalkal

The purpose of this paper is to study two-dimensional deformations in a nonlocal, homogeneous, isotropic, rotating thermoelastic medium with temperature-dependent…

Abstract

Purpose

The purpose of this paper is to study two-dimensional deformations in a nonlocal, homogeneous, isotropic, rotating thermoelastic medium with temperature-dependent properties under the purview of the Green-Naghdi model II of generalized thermoelasticity. The formulation is subjected to a mechanical load.

Design/methodology/approach

The normal mode analysis technique is adopted to procure the exact solution of the problem.

Findings

For isothermal and insulated boundaries, discussions have been made to highlight the influences of rotational speed, nonlocality, temperature-dependent properties and time on the physical quantities.

Originality/value

The exact expressions for the displacement components, stresses and temperature field are obtained in the physical domain. These are also calculated numerically for a magnesium crystal-like material and depicted through graphs to observe the variations of the considered physical quantities. The present study is useful and valuable for the analysis of problems involving mechanical shock, rotational speed, nonlocal parameter, temperature-dependent properties and elastic deformation.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 27 July 2012

Skylar Tibbits and Kenny Cheung

The purpose of this paper is to explain a current implementation of a programmable and computational material, Logic Matter, and to describe potential applications for…

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2086

Abstract

Purpose

The purpose of this paper is to explain a current implementation of a programmable and computational material, Logic Matter, and to describe potential applications for computational materials and self‐guided assembly.

Design/methodology/approach

Following an introduction, the paper describes the types of information currently found in architectural construction, then introduces Logic Matter, a building block embodying physical digital logic. Examples of structural optimization and construction scenarios are given, to demonstrate the benefits of programmable and computational physical materials for assembly.

Findings

Logic Matter demonstrates a prototype with embedded digital logic and programmability, offering new applications for automated assembly, online material analysis and physical computing.

Originality/value

The paper describes the existing types of architectural construction information and proposes a novel application of programmable and computational material for automated assembly.

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Article
Publication date: 31 May 2013

Yongrong Wang and Peihua Zhang

This study aims to clarify the key factors among physical‐mechanical properties of fabrics in relation to the dynamic pressure performance of compression garment.

Abstract

Purpose

This study aims to clarify the key factors among physical‐mechanical properties of fabrics in relation to the dynamic pressure performance of compression garment.

Design/methodology/approach

The physical‐mechanical properties of 16 different fabrics were measured using a KESF standard evaluation system and INSTRON tensile tester, and the garment pressure was measured by dynamic pressure measuring system. Grey correlation analysis is used to determine the correlation degree of fabric physical‐mechanical properties and dynamic pressure magnitude.

Findings

The mechanical behaviors (e.g. tensile, shearing, and bending) and physical characteristics are different in elastic fabrics with varied content of elastic fiber, kinds of yarn, et al. Grey correlation analysis is a valid method to analyze the indices of a system, quantize them and put them in order. All the degrees of Grey correlation are more than 0.6. The degree of grey correlation between tensile force (F), shearing rigidity (G) and bending rigidity (B) are higher than others, hence it is conducted that these would significantly effect on garment pressure. The quantitative regression equations between pressure magnitude at extension of 50 percent and the individual key parameters (mean values in wale and course directions) of tested samples are illustrated.

Research limitations/implications

The other parameters (e.g. fabric structure, yarn fineness, and pre‐tension, et al.) should be taken into account. Further, an integrative mathematic model would be established, which could predict the garment pressure directly from the physical‐mechanical properties of fabric.

Originality/value

The present study indicates that pressure magnitude of elastic fabric is an integrative action performed by physical‐mechanical properties. The developed illustrative equations and method offer a rational and practical tool for assessing pressure functional performance of elastic fabric in the stages of design and product development.

Details

International Journal of Clothing Science and Technology, vol. 25 no. 2
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 March 1988

G.A. Green and F.J. Tribe

Submarine propeller shaft seals operate under onerous conditions in an aggressive environment and their effective life is vitally dependent upon the durability of the seal…

Abstract

Submarine propeller shaft seals operate under onerous conditions in an aggressive environment and their effective life is vitally dependent upon the durability of the seal face materials. The combination of physical and mechanical properties of certain carbon‐carbon composites makes them potentially suitable for this critical service, but a literature search revealed no prior reference to their deployment in any liquid sealing application nor, indeed, to their behaviour in an aqueous environment. In consequence, a programme of work has been carried out to determine the effect of prolonged exposure to high‐pressure sea water upon their properties, and to assess their performance when run in a seal test rig against a variety of counter surfaces. The assessments were made under a reproducible condition of boundary lubrication stabilised by control of interface torque. The effects of composite anisotrophy and of graphitisation have been examined using specimen rings with the direction of fibre lay‐up either in, or normal to, the rubbing plane, and in the graphitised or non‐graphitised condition. It has been shown that the carbon‐carbon composites are stable in water and perform well as a seal face material; however, current high procurement cost will probably restrict their use to the more exacting applications.

Details

Industrial Lubrication and Tribology, vol. 40 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 June 2012

Wenfang Song, Qian Liu and Weidong Yu

The purpose of this paper is to describe a new apparatus for testing acoustic insulating, air permeating and water vapor transfer properties of fibrous assemblies with…

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193

Abstract

Purpose

The purpose of this paper is to describe a new apparatus for testing acoustic insulating, air permeating and water vapor transfer properties of fibrous assemblies with density variation.

Design/methodology/approach

An apparatus is designed and built in order to investigate the acoustic insulating, air permeating and water vapor transfer properties of fiber assemblies with density variation. The apparatus mainly consists of three chambers, just like the structure of a syringe. The three properties can be measured by placing different sensors at the corresponding chambers. The material density variation can be realized by compression.

Findings

The new apparatus can realize the measurement of the three properties with density variation, which provides a new perspective to study the physical property of fibrous assemblies.

Originality/value

The paper introduces a new apparatus for testing acoustic insulating, air permeating and water vapor transfer properties of fibrous assemblies with density variation.

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Article
Publication date: 19 October 2015

Janusz Domanski, Konstanty Skalski, Roman Grygoruk and Adrian Mróz

The purpose of this paper is to present the methodology of a design process of new lumbar intervertebral disc implants with specific emphasis on the use of rapid…

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856

Abstract

Purpose

The purpose of this paper is to present the methodology of a design process of new lumbar intervertebral disc implants with specific emphasis on the use of rapid prototyping technologies. The verification of functionality of artificial intervertebral discs is also given. The paper describes the attempt and preliminary research to evaluate the properties of the intervertebral disc implant prototypes manufactured with the use of different rapid prototyping technologies, i.e. FDM – fused deposition modelling, 3DP – 3D printing and SLM – selective laser melting.

Design/methodology/approach

Based on the computed tomography (CT) scan data, the anatomical parameters of lumbar spine bone tissue were achieved, which were the bases for the design-manufacture process carried out with the use of computer-aided designing/computer-aided engineering/computer-aided manufacturing systems. In the intervertebral disc implant design process, three RP technologies: FDM, 3DP and SLM were used for solving problems related to the reconstruction of geometry and functionality of the disc. Some preliminary tests such as measurement of roughness and structural analyses of material of prototypes made by different prototyping technologies were performed.

Findings

This paper allowed the authors to elaborate and patent two new intervertebral disc implants. Because the implant designs are parametrical ones with relation to lumbar bone tissue properties measured on CT scans, they can be also made for individual patients. We also compared some of the properties of intervertebral implants prototypes made with the use of FDM, 3DP and SLM technologies.

Originality/value

The paper presents the new intervertebral disc implants and their manufacturing by rapid prototyping. The methodology of designing intervertebral disc implant is shown. Some features of the methodology make it useful for preoperative planning of intervertebral disc surgery, as well.

Details

Rapid Prototyping Journal, vol. 21 no. 6
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 31 May 2013

M. Farzandi, S. Razipour, F. Mousazadegan and S. Saharkhiz

The paper aims to study changes in physical and mechanical properties of wind stoppers after fusing process.

Abstract

Purpose

The paper aims to study changes in physical and mechanical properties of wind stoppers after fusing process.

Design/methodology/approach

Effect of fusing process on physical, mechanical properties of windproof fabrics for two types of windproof fabrics and four interlinings were studied. Properties including air permeability, drape, flexural rigidity, water vapor permeability, thickness, crease recovery and water repellency have been investigated.

Findings

It was found that fusing process and using interlining, improves flexural rigidity, crease recovery, drape and increases air permeability and water vapor permeability of the final assembly where as it has no effect on water repellency property of windproof fabric.

Originality/value

Wind stoppers are kinds of windproof and in some cases waterproof fabrics that have breathability property. They stop air penetrating fabric while letting water vapor pass through. One of the problems associated with garments made of these kinds of fabrics is lack of attractive appearance when worn. One solution to this problem is to fuse windproof fabrics with interlinings to increase flexural rigidity, drape, formability and serviceability or functionality. This study investigates effect of fusing process on main physical and mechanical properties of windproof fabric which may influence their performance besides aesthetic aspect.

Details

International Journal of Clothing Science and Technology, vol. 25 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 28 June 2019

Wendong Zheng, Huaping Liu, Bowen Wang and Fuchun Sun

For robots to more actively interact with the surrounding environment in object manipulation tasks or walking, they must understand the physical attributes of objects and…

Abstract

Purpose

For robots to more actively interact with the surrounding environment in object manipulation tasks or walking, they must understand the physical attributes of objects and surface materials they encounter. Dynamic tactile sensing can effectively capture rich information about material properties. Hence, methods that convey and interpret this tactile information to the user can improve the quality of human–machine interaction. This paper aims to propose a visual-tactile cross-modal retrieval framework to convey tactile information of surface material for perceptual estimation.

Design/methodology/approach

The tactile information of a new unknown surface material can be used to retrieve perceptually similar surface from an available surface visual sample set by associating tactile information to visual information of material surfaces. For the proposed framework, the authors propose an online low-rank similarity learning method, which can effectively and efficiently capture the cross-modal relative similarity between visual and tactile modalities.

Findings

Experimental results conducted on the Technischen Universität München Haptic Texture Database demonstrate the effectiveness of the proposed framework and the method.

Originality/value

This paper provides a visual-tactile cross-modal perception method for recognizing material surface. By the method, a robot can communicate and interpret the conveyed information about the surface material properties to the user; it will further improve the quality of robot interaction.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 3
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 June 2002

Roger L. Barker

This paper traces the evolution of objective measurement of textile hand and comfort from Pierce through modern methodology and approaches. Special emphasis is given to…

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3419

Abstract

This paper traces the evolution of objective measurement of textile hand and comfort from Pierce through modern methodology and approaches. Special emphasis is given to discuss the contribution of the Kawabata Evaluation System (KES) towards advancing the state of objective measurement. Laboratory case studies are used to show how data generated by the KES and other instruments can be integrated into a comprehensive approach that attempts to explain human comfort response to garment wear in terms of fabric mechanical, surface and heat and moisture transfer properties.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 3/4
Type: Research Article
ISSN: 0955-6222

Keywords

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