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Article
Publication date: 14 November 2008

George K. Stylios

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

1246

Abstract

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 20 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 7 December 2020

Rafael Moreno, Diego Carou, Daniel Carazo-Álvarez and Munish Kumar Gupta

3D printing is gaining attention in the medical sector for the development of customized solutions for a wide range of applications such as temporary external implants. The…

Abstract

Purpose

3D printing is gaining attention in the medical sector for the development of customized solutions for a wide range of applications such as temporary external implants. The materials used for the manufacturing process are critical, as they must provide biocompatibility and adequate mechanical properties. This study aims to evaluate and model the influence of the printing parameters on the mechanical properties of two biocompatible materials.

Design/methodology/approach

In this study, the mechanical properties of 3D-printed specimens of two biocompatible materials (ABS medical and PLActive) were evaluated. The influence of several printing parameters (infill density, raster angle and layer height) was studied and modelled on three response variables: ultimate tensile strength, deformation at the ultimate tensile strength and Young’s modulus. Therefore, statistical models were developed to predict the mechanical responses based on the selected printing parameters.

Findings

The used methodology allowed obtaining compact models that show good fit, particularly, for both the ultimate tensile strength and Young’s modulus. Regarding the deformation at ultimate tensile strength, this output was found to be influenced by more factors and interactions, resulting in a slightly less precise model. In addition, the influence of the printing parameters was discussed in the work.

Originality/value

The presented paper proposed the use of statistical models to select the printing parameters (infill density, raster angle and layer height) to optimize the mechanical response of external medical aids. The models will help users, researchers and firms to develop optimized solutions that can reduce material costs and printing time but guaranteeing the mechanical response of the parts.

Details

Rapid Prototyping Journal, vol. 27 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 April 1988

Balbir S. Dhillon and Subramanyam N. Rayapati

A newly developed model for performing reliability and availability analysis of mechanical devices subject to multiple failure modes is presented. Using this model, reliability…

Abstract

A newly developed model for performing reliability and availability analysis of mechanical devices subject to multiple failure modes is presented. Using this model, reliability analyses of mechanical devices such as brakes, bearings, engines, fans, gears, generators, heat exchangers and pumps are developed. Real life failure rate data for these devices are obtained from various sources and are used in their reliability analyses. Principal failure modes of these devices are identified and expressions for reliability, state probabilities, mean time to failure and variance of time to failure are developed. For known field failure data reliability and state probability plots are shown.

Details

International Journal of Quality & Reliability Management, vol. 5 no. 4
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 17 May 2022

Massicilia Dahmani, Abdelghani Seghir, Nabil Issaadi and Ouali Amiri

This study aims to propose a numerical modeling procedure for response analysis of elastic body floating in water and submitted to regular waves. An equivalent simplified…

Abstract

Purpose

This study aims to propose a numerical modeling procedure for response analysis of elastic body floating in water and submitted to regular waves. An equivalent simplified mechanical single-degree-of-freedom system allowing to reproduce the heave movements is first developed, then the obtained lumped characteristics are used for elastic analysis of the floating body in heave motion.

Design/methodology/approach

First, a two-dimensional numerical model of a rigid floating body in a wave tank is implemented under DualSPHysics, an open source computational fluid dynamics (CFD) code based on smoothed particle hydrodynamics method. Then, the obtained results are exploited to derive an equivalent mechanical mass-spring-damper model. Finally, estimated equivalent characteristics are used in a structural finite element modeling of the considered body assuming elastic behavior.

Findings

Obtained results concerning the floating body displacements are represented and validated using existing experimental data in the literature. Wave forces acting on the body are also evaluated. It was found that for regular waves, it is possible to replace the complex CFD refined model by an equivalent simplified mechanical system which makes easy the use of structural finite element analysis.

Originality/value

The originality of this work lies in the proposed procedure to evaluate the mechanical properties of the equivalent elastic system. This allows to couple two different software tools and to take advantages of their features.

Details

World Journal of Engineering, vol. 20 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 April 1992

JAROSLAV MACKERLE

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE…

Abstract

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.

Details

Engineering Computations, vol. 9 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 25 July 2019

Zhoupeng Han, Rong Mo, Haicheng Yang and Li Hao

Three-dimensional computer-aided design (CAD) assembly model has become important resource for design reuse in enterprises, which implicates plenty of design intent, assembly…

Abstract

Purpose

Three-dimensional computer-aided design (CAD) assembly model has become important resource for design reuse in enterprises, which implicates plenty of design intent, assembly intent, design experience knowledge and functional structures. To acquire quickly CAD assembly models associated with specific functions by using product function requirement information in the product conceptual design phase for model reuse, this paper aims to find an approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model before functional semantic-based assembly retrieval.

Design/methodology/approach

An approach for structure-function correlations analysis and functional semantic annotation of CAD assembly model is proposed. First, the product knowledge model is constructed based on ontology including design knowledge and function knowledge. Then, CAD assembly model is represented by part attributed adjacency graph and partitioned into multiple functional regions. Assembly region and flow-activity region are defined for structure-function correlations analysis of CAD assembly model. Meanwhile, the extraction process of assembly region and flow-activity region is given in detail. Furthermore, structure-function correlations analysis and functional semantic annotation are achieved by considering comprehensively assembly structure and assembled part shape structure in CAD assembly model. After that, a structure-function relation model is established based on polychromatic sets for expressing explicitly and formally relationships between functional structures, assembled parts and functional semantics.

Findings

The correlation between structure and function is analyzed effectively, and functional semantics corresponding to structures in CAD assembly model are labeled. Additionally, the relationships between functional structures, assembled parts and functional semantics can be described explicitly and formally.

Practical implications

The approach can be used to help designers accomplish functional semantic annotation of CAD assembly models in model repository, which provides support for functional semantic-based CAD assembly retrieval in the product conceptual design phase. These assembly models can be reused for product structure design and assembly process design.

Originality/value

The paper proposes a novel approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model. Functional structures in assembly model are extracted and analyzed from the point of view of assembly structure and function part structure. Furthermore, the correlation relation between structures, assembled parts and functional semantics is expressed explicitly and formally based on polychromatic sets.

Details

Assembly Automation, vol. 39 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 13 June 2016

Mica Grujicic, Jennifer Snipes and S Ramaswami

The purpose of this paper is to propose a computational approach to establish the effect of various flow drilling screw (FS) process and material parameters on the quality and the…

Abstract

Purpose

The purpose of this paper is to propose a computational approach to establish the effect of various flow drilling screw (FS) process and material parameters on the quality and the mechanical performance of the resulting FS joints.

Design/methodology/approach

Toward that end, a sequence of three distinct computational analyses is developed. These analyses include: (a) finite-element modeling and simulations of the FS process; (b) determination of the mechanical properties of the resulting FS joints through the use of three-dimensional, continuum finite-element-based numerical simulations of various mechanical tests performed on the FS joints; and (c) determination, parameterization and validation of the constitutive relations for the simplified FS connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle component manufacturing, e.g. car-body electro-coat paint-baking process. In such simulations, explicit three-dimensional representation of all FS joints is associated with a prohibitive computational cost.

Findings

Virtual testing of the shell components fastened using the joint connectors validated the ability of these line elements to realistically account for the strength, ductility and toughness of the three-dimensional FS joints.

Originality/value

The approach developed in the present work can be used, within an engineering-optimization procedure, to adjust the FS process and material parameters (design variables) in order to obtain a desired combination of the FS-joint mechanical properties (objective function).

Details

International Journal of Structural Integrity, vol. 7 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 29 March 2022

Saeed Hatefi Ardakani, Peyman Fatemi Dehaghani, Hesam Moslemzadeh and Soheil Mohammadi

The purpose is to analyze the mechanical behavior of the arterial wall in the degraded region of the arterial wall and to determine the stress distribution, as an important factor…

Abstract

Purpose

The purpose is to analyze the mechanical behavior of the arterial wall in the degraded region of the arterial wall and to determine the stress distribution, as an important factor for predicting the potential failure mechanisms in the wall. In fact, while the collagen fiber degradation process itself is not modeled, zones with reduced collagen fiber content (corresponding to the degradation process) are assumed. To do so, a local weakness in the media layer is considered by defining representative volume elements (RVEs) with different fiber collagen contents in the degraded area to investigate the mechanical response of the arterial wall.

Design/methodology/approach

A three-dimensional (3D) large strain hierarchical multiscale technique, based on the homogenization and genetic algorithm (GA), is utilized to numerically model collagen fiber degradation in a typical artery. Determination of material constants for the ground matrix and collagen fibers in the microscale level is performed by the GA. In order to investigate the mechanical degradation, two types of RVEs with different collagen contents in fibers are considered. Each RVE is divided into two parts of noncollagenous matrix and collagen fiber, and the part of collagen fiber is further divided into matrix and collagen fibrils.

Findings

The von Mises stress distributions on the inner and outer surfaces of the artery and the influence of collagen fiber degradation on thinning of the arterial wall in the degraded area are thoroughly studied. Comparing the maximum stress values on outer and inner surfaces in the degraded region shows that the inner surface is under higher stress states, which makes it more prone to failure. Furthermore, due to the weakness of the artery in the degraded area, it is concluded that the collagen fiber degradation considerably reduces the wall thickness in the degraded area, leading to an observable local inflation across the degraded artery.

Originality/value

Considering that little attention has been paid to multiscale numerical modeling of collagen fiber degradation, in this paper a 3D large strain hierarchical multiscale technique based on homogenization and GA methods is presented. Therefore, while the collagen fiber degradation process itself is not modeled in this study, zones with reduced collagen fiber content (corresponding to the degradation process) are assumed.

Details

Engineering Computations, vol. 39 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 October 2004

Christopher G. Provatidis and Savvas G. Vassiliadis

The computer aided engineering and the respective computer aided design tools compose a modern mechanical modelling environment for the textile materials. The numerical mechanical

Abstract

The computer aided engineering and the respective computer aided design tools compose a modern mechanical modelling environment for the textile materials. The numerical mechanical models of the textile structures are a strong tool for the in‐depth study of the mechanical properties and the behaviour of the textiles. The precision of these models in terms of their accuracy in representing the exact geometry of the real textile structures is the fundamental factor affecting the overall success of the idealisation. This paper discusses older traditional analytical models (Peirce, Saw‐tooth, Kemp) as well as some variations of these fundamental models. Their numerical solutions are successfully compared to the experimental measurements of the yarn longitudinal deformation parameters using microscopic and digital image processing techniques. The results of the analytical models are compared with the actual measurements and the more precise models are indicated.

Details

International Journal of Clothing Science and Technology, vol. 16 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 8 January 2020

Mingyong Liu, Peidong Xu, Jinxi Zhang and Huafeng Ding

Power loss is an important index to evaluate the transmission performance of a gear pair. In some cases, the starved lubrication exists on the gear contact interface. The purpose…

Abstract

Purpose

Power loss is an important index to evaluate the transmission performance of a gear pair. In some cases, the starved lubrication exists on the gear contact interface. The purpose of this paper is to reveal the mechanical power loss of a helical gear pair under starved lubrication.

Design/methodology/approach

A starved thermal-elastohydrodynamic lubrication (EHL) model is proposed to evaluate the tribological properties of a helical gear pair. The numerical result has been validated against the published simulation data. Based on the proposed model, the influence of thermal effect, working conditions, inlet oil-supply layer and surface roughness on the mechanical power loss and lubrication performance has been discussed.

Findings

Results show that the thermal effect has a significant effect on the tribological properties of helical gear pair, especially on mechanical power loss. For a specified working condition, there is an optimal oil supply for gear lubrication to obtain the state of full film lubrication. Meanwhile, it reveals that the mechanical power loss increases with the increase of the surface roughness amplitude.

Originality/value

In this paper, a starved thermal-EHL model has been developed for the helical gear pair based on the finite line contact theory. This model can be used to analyze the tribological properties of gear pair from full film lubrication to mixed lubrication. The results can provide the tribological guidance for design of a helical gear pair.

Details

Industrial Lubrication and Tribology, vol. 72 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

21 – 30 of over 41000