Search results

1 – 10 of over 8000
To view the access options for this content please click here
Article
Publication date: 1 October 2004

Savvas G. Vassiliadis and Christopher G. Provatidis

The surface of the textile fabrics is not absolutely flat and smooth. Its geometrical roughness within certain extents is considerable. The surface roughness influences…

Abstract

The surface of the textile fabrics is not absolutely flat and smooth. Its geometrical roughness within certain extents is considerable. The surface roughness influences the fabric hand and it plays a significant role in the end use of the fabric. In parallel, the periodic variations of the fabric surface level due to the regular interlaced patterns of the yarns cause a respective variation of the geometrical roughness measurement. Thus, the fabric roughness data measured using the Kawabata Evaluation System for Fabrics and imposed to a certain process of numerical calculations result into the retrieval of the structural parameters of the fabric. The principle of the method has a non‐destructive character and can be applied to woven or knitted fabrics.

Details

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

Keywords

To view the access options for this content please click here
Article
Publication date: 17 April 2001

Ma Zizong and Zhao Fengyu Xu Jichao

The economic design of specification limits must be determined on an economic basis where we minimize total loss to society, which consists of both the producer and the…

Abstract

The economic design of specification limits must be determined on an economic basis where we minimize total loss to society, which consists of both the producer and the consumer. Economic specification limits have been developed based on the assumption that the quality characteristic is normally distributed. Unfortunately, the assumption is not to meet some practical cases. In this paper, some non‐normal distributions are considered for quality characteristic with geometrical features. An economic model for selecting the optimum specification limits on the basis of minimizing total cost is introduced. A case study is presented to illustrate the application in practice.

Details

Asian Journal on Quality, vol. 2 no. 1
Type: Research Article
ISSN: 1598-2688

Keywords

To view the access options for this content please click here
Article
Publication date: 13 January 2012

M. Averyanova, E. Cicala, Ph. Bertrand and Dominique Grevey

The purpose of this paper is to investigate the effect of main process parameters of selective laser melting (SLM) technology on single lines and single layers…

Abstract

Purpose

The purpose of this paper is to investigate the effect of main process parameters of selective laser melting (SLM) technology on single lines and single layers manufactured from 17‐4 PH martensitic powder using the experimental design approach.

Design/methodology/approach

A fractional factorial approach has been applied to vary and to identify the optimal set of process parameters using three different powder particle size distributions for 17‐4 PH steel. This paper assesses the impact of influence factors such as process and material parameters on objective factors such as dimension of single lines and single layers, as well as surface roughness.

Findings

The influence of process parameters and materials properties on single line and single layer manufacture is shown and proved statistically. The effect of each process parameter and their interactions on single layer and single line stability and quality has been investigated, and a complex objective function analyzing geometrical stability of single lines has been proposed. The findings indicate the most appropriate 17‐4 PH powder particle size distribution.

Originality/value

The research provides a systematic scientific approach using fractional factorial experiment design to identify the influence of process parameters, materials parameters and their combinations on essential martensitic steels (17‐4 PH steel) single lines and single layers characteristics such as geometrical stability and surface roughness. This approach will be extended to 3D parts fabrication and reported in a later paper.

Details

Rapid Prototyping Journal, vol. 18 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

To view the access options for this content please click here
Book part
Publication date: 13 January 2010

Tony Kazda and Bob Caves

Abstract

Details

Airport Design and Operation
Type: Book
ISBN: 978-0-08-054643-8

To view the access options for this content please click here
Book part
Publication date: 5 August 2015

Tony Kazda and Bob Caves

Abstract

Details

Airport Design and Operation
Type: Book
ISBN: 978-1-78441-869-4

To view the access options for this content please click here
Article
Publication date: 5 May 2015

Da-Wei Zhang and He Yang

The purpose of this paper is to explore the basic loading state in local loading forming process of large-sized complicated rib-web component, which is important for…

Abstract

Purpose

The purpose of this paper is to explore the basic loading state in local loading forming process of large-sized complicated rib-web component, which is important for understanding process characteristic, controlling metal flow and designing preformed geometry of the local loading forming process. Moreover the analytical models for different loading states are established to quickly predict the metal flow.

Design/methodology/approach

Through analysis of geometric characteristic of large-sized complicated rib-web component and the deformation characteristic on planes of metal flow by local loading method, a representative cross-section is put forward and designed, which could reflect the local loading forming characteristics of large-sized complicated rib-web component. Finite element method (FEM) is used to analyze the stress and metal flow, and the analytical models of metal flow are established by using slab method (SM).

Findings

Three local loading states and one whole loading state are found in the local loading forming process of representative cross-section. Further, four loading states also exist in local loading forming process of large-sized complicated rib-web components. With the metal distribution in the process, some local loading states may turn into whole loading state. For the representative cross-section, the relative error of metal distribution between SM and FEM results is less than 15 per cent, and the relative error of metal in the rib cavity between SM and FEM results is less than 10 per cent.

Originality/value

Metal flow can be controlled by adjusting the loading states in the process. According to the metal flow laws in different loading states, a simple unequal-thickness billet can be designed to achieve initial metal distribution, and then, the secondary metal distribution can be achieved in the process.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 87 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 1 June 1997

Nan‐Shing Ong, Chee‐Kai Chua and Eng‐Wah Lee

Presents the development of an AutoCAD development system (ADS) application program for the automatic analysis of parts in mechanical assembly. The primary goal is to…

Abstract

Presents the development of an AutoCAD development system (ADS) application program for the automatic analysis of parts in mechanical assembly. The primary goal is to provide design engineers with a tool for extracting the part’s characteristics from the 3‐D solid model AutoCAD database. With this information and other non‐geometric information, the time for assembling the part can be determined. Describes the algorithms used to evaluate the rotational symmetries from the solid model database. Twelve 3‐D solid models are designed to evaluate the program capabilities. The overall performance of the program is satisfactory in terms of speed. It also provides a low‐cost PC‐based, fully‐functional alternative to the more expensive workstation‐based analysis program.

Details

Integrated Manufacturing Systems, vol. 8 no. 3
Type: Research Article
ISSN: 0957-6061

Keywords

To view the access options for this content please click here
Article
Publication date: 3 July 2017

Dimitrios Chronopoulos, Manuel Collet and Mohamed Ichchou

This paper aims to present the development of a numerical continuum-discrete approach for computing the sensitivity of the waves propagating in periodic composite…

Abstract

Purpose

This paper aims to present the development of a numerical continuum-discrete approach for computing the sensitivity of the waves propagating in periodic composite structures. The work can be directly used for evaluating the sensitivity of the structural dynamic performance with respect to geometric and layering structural modifications.

Design/methodology/approach

A structure of arbitrary layering and geometric complexity is modelled using solid finite element (FE). A generic expression for computing the variation of the mass and the stiffness matrices of the structure with respect to the material and geometric characteristics is hereby given. The sensitivity of the structural wave properties can thus be numerically determined by computing the variability of the corresponding eigenvalues for the resulting eigenproblem. The exhibited approach is validated against the finite difference method as well as analytical results.

Findings

An intense wavenumber dependence is observed for the sensitivity results of a sandwich structure. This exhibits the importance and potential of the presented tool with regard to the optimization of layered structures for specific applications. The model can also be used for computing the effect of the inclusion of smart layers such as auxetics and piezoelectrics.

Originality/value

The paper presents the first continuum-discrete approach specifically developed for accurately and efficiently computing the sensitivity of the wave propagation data for periodic composite structures irrespective of their size. The considered structure can be of arbitrary layering and material characteristics as FE modelling is used.

Details

Engineering Computations, vol. 34 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

To view the access options for this content please click here
Article
Publication date: 4 March 2020

Eva Lubloy

The aim of the research was to investigate the effect of concrete strength on the fire resistance of structures. At first, it may seem contradictory that higher concrete…

Abstract

Purpose

The aim of the research was to investigate the effect of concrete strength on the fire resistance of structures. At first, it may seem contradictory that higher concrete strengths can decrease the fire resistance of building structures. However, if the strength of the concrete exceeds a maximum value, the risk of spalling (the detachment of the concrete surface) significantly.

Design/methodology/approach

Prefabricated structural elements are often produced with higher strength. The higher concrete strengths generally do not cause a reduction in the load bearing capacity, but it can have serious consequences in case of structural fire design. Results of two prefabricated elements, namely, one slab (TT shaped panel) and one single layer wall panel, were examined. Results of the specimen with the originally designed composition and a specimen with modified concrete composition were examined, were polymer fibres were added to prevent spalling.

Findings

As a result of the experiments, more strict regulations in the standards the author is suggested including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is required after polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons.

Originality/value

As a result of the experiments, the author suggests including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is necessary to require the addition of polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons.

Details

Journal of Structural Fire Engineering, vol. 11 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

To view the access options for this content please click here
Article
Publication date: 1 June 2012

Chiahsu Lin and Chorng H. Twu

Based on the developed personal pleasure fashion design model (PPFDM), the authors have developed six fashion trend alternatives. The purpose of this paper is to use the…

Abstract

Purpose

Based on the developed personal pleasure fashion design model (PPFDM), the authors have developed six fashion trend alternatives. The purpose of this paper is to use the fuzzy multiple criteria decision making (MCDM) to select the best fashion trend alternative.

Design/methodology/approach

To rationalize uncertainty associated with fuzzy, the fuzzy analytic hierarchy process (fuzzy AHP) is proposed in this work to calculate the weight for the criteria. The synthetic evaluation is used to calculate the score for each criterion from the best non‐fuzzy performance (BNP) values and the weight of the criterion. The scores for each criterion are summed up to rank the importance of the alternatives.

Findings

The results show that the preferred trend of the alternatives is in the order of Romantic hippy, followed by Greek goddess, then Black knight, Urban punk, Country yappy, and Sporty academy. The multiple dimension scale (MDS) is used to visualize the preferred fashion trend alternatives; it reveals that the preference image goes from romantic to urban, to country, and finally to sporty.

Originality/value

The paper offers important criteria for the selection of fashion trend alternatives. The calculation examples provide insight into the complicated fuzzy AHP and MDS methods to clarify each step in fuzzy MCDM. This study, through using MDS, uncovers that material‐oriented consumers will purchase products or brands that are congruent with their inner femininity desire to create their personal identity and self‐image. Moreover, the developed framework has proven to be useful in improving the quality of fashion design decision.

Details

International Journal of Clothing Science and Technology, vol. 24 no. 2/3
Type: Research Article
ISSN: 0955-6222

Keywords

1 – 10 of over 8000