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Article
Publication date: 25 September 2009

Yuan Mao Huang and Yu‐Chung Liao

The purpose of this paper is to enhance the method developed by previous researchers. In addition to using the combined interference matrix, the combined connection matrix

Abstract

Purpose

The purpose of this paper is to enhance the method developed by previous researchers. In addition to using the combined interference matrix, the combined connection matrix and the combined contact matrix of product components, the disassembly sequence matrix and the combined instability matrix with platform to evaluate instability of sub‐assemblies are built, and effects of changes of sub‐assembly disassembly directions or tools and the effect of gravity are considered to obtain the best disassembly sequence for a product with many components. A computer program is generated and results of two cases are compared with those of the available studies.

Design/methodology/approach

The methodology includes the combined interference matrix, the combined contact matrix and the combined connection matrix of components for a product. The combined instability matrix of sub‐assemblies, changes of sub‐assembly disassembly direction or tools, and the effect of gravity during operation are considered. The binary number system is used to simplify relations among components of a product.

Findings

This methodology enhances the existing method and software is generated. Results of two cases are compared and show the same optimum disassembly processes as those obtained from other researchers.

Research limitations/implications

All matrices are defined by the directions of x, y and z with three axes perpendicular to each other. The computer program generated cannot be used for a product with components that must be disassembled in the directions different from the axes.

Practical implications

Two cases are used to investigate feasibility of the proposed methodology with the computer program generated. The first one is an electric drill, and the second one is a flash lighter.

Originality/value

The methodology described in this paper is feasible for study of disassembly processes of products. The software generated can be used to obtain the optimum disassembly process of products.

Details

Assembly Automation, vol. 29 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 27 May 2014

Masoud Hajarian

The linear matrix equations have wide applications in engineering, physics, economics and statistics. The purpose of this paper is to introduce iterative methods for…

Abstract

Purpose

The linear matrix equations have wide applications in engineering, physics, economics and statistics. The purpose of this paper is to introduce iterative methods for solving the systems of linear matrix equations.

Design/methodology/approach

According to the hierarchical identification principle, the authors construct alternating direction gradient-based iterative (ADGI) methods to solve systems of linear matrix equations.

Findings

The authors propose efficient ADGI methods to solve the systems of linear matrix equations. It is proven that the ADGI methods consistently converge to the solution for any initial matrix. Moreover, the constructed methods are extended for finding the reflexive solution to the systems of linear matrix equations.

Originality/value

This paper proposes efficient iterative methods without computing any matrix inverses, vec operator and Kronecker product for finding the solution of the systems of linear matrix equations.

Details

Engineering Computations, vol. 31 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 April 1985

C.A.M. Oliveira and R.A.F. Martins

The Semiloof shell element stiffness and mass matrices are analysed. Various integration rules for the stiffness matrix are used, and the influence of these rules on the…

Abstract

The Semiloof shell element stiffness and mass matrices are analysed. Various integration rules for the stiffness matrix are used, and the influence of these rules on the existence of mechanisms and on the element spectra is studied. Some methods for lumping the mass matrix are attempted with special reference to a method imposing a given behaviour of the spectra of eigenvalues.

Details

Engineering Computations, vol. 2 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 July 1998

Ralf Östermark

In the present study we introduce a new recursive matrix inversion (RMI) algorithm for a distributed memory computer. The RMI algorithm was designed to meet the…

Abstract

In the present study we introduce a new recursive matrix inversion (RMI) algorithm for a distributed memory computer. The RMI algorithm was designed to meet the requirements of high performance flexible software for implementing different parallel optimization algorithms. Special consideration has been taken to ensure the usability and portability of the algorithm. The results we present show that a significant improvement in performance is attainable over the LU‐factorization algorithm included in the LAPACK library.

Details

Kybernetes, vol. 27 no. 5
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 4 January 2016

Xiayu Zheng, Yuhua Wang and Dongfang Lu

The purpose of this paper is to model the particle capture of elliptic magnetic matrices for parallel stream type high magnetic separation, which can be a guidance for the…

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Abstract

Purpose

The purpose of this paper is to model the particle capture of elliptic magnetic matrices for parallel stream type high magnetic separation, which can be a guidance for the development of novel elliptic cylinder matrices for high-gradient magnetic separation (HGMS).

Design/methodology/approach

The magnetic field distribution around the elliptic matrices is investigated quantitatively and the magnetic field and gradient were calculated. The motion equations of the magnetic particles around the matrices were derived and the particle capture cross-section of elliptic matrices was studied and was compared with that of the conventional circular matrices.

Findings

Elliptic matrices can present larger particle capture cross-section than the conventional circular matrices and can be a kind of promising matrices to be applied to HGMS.

Originality/value

There is little literature investigating the magnetic characteristics and the particle capture of the elliptic matrices in HGMS, the study is of great significance for the development of novel elliptic magnetic matrices in HGMS.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 25 February 2014

Shiuh-Chuan Her and Shou-Jan Liu

Carbon nanotubes (CNTs) with exceptional mechanical, thermal and electrical properties are considered to be ideal for reinforcing high-performance structures. The…

Abstract

Purpose

Carbon nanotubes (CNTs) with exceptional mechanical, thermal and electrical properties are considered to be ideal for reinforcing high-performance structures. The interfacial stresses between the CNTs and surrounding matrix are important phenomena which critically govern the mechanical properties of CNTs-reinforced nanocomposites. A number of methods have been proposed to investigate the stress transfer across the CNT/matrix interface, such as experimental measurement and molecular dynamics (MDs). Experimental tests are difficulty and expensive. MDs simulations, on the other hand, are computationally inefficient. The purpose of this paper is to present a reasonably simplified model. Incorporating the simplified model, the analytical expressions of the interface stresses including the shear stress and longitudinal normal stress are obtained.

Design/methodology/approach

The analytical model consists of two concentric cylinders, namely a single-walled carbon nanotube (SWCNT) cylinder and a matrix cylinder, as the representative volume element (RVE). The interfacial stress analysis is performed using the shear lag model for the axisymmetric RVE. Analytical solutions for the normal stresses in the SWCNT and matrix, and the interfacial shear stress across the SWCNT/matrix interface are obtained. The proposed model has a great ability to theoretical prediction of the stress transfer between the matrix and CNTs.

Findings

In order to demonstrate the simulation capabilities of the proposed model, parametric studies are conducted to investigate the effects of the volume fraction of SWCNT and matrix modulus on the stress transfer. The axial stress in the matrix is decreasing with the increase of the volume fraction and decrease of the matrix modulus. As a result of more loads can be transferred to the SWCNT for a large volume fraction and small matrix modulus. These results show that using a large volume fraction and a small matrix modulus improves the efficiency of the stress transfer from the matrix to the CNTs.

Originality/value

A simple but accurate model using a simplified 2D RVE for characterizing the stress transfer in CNT-reinforced nanocomposites is presented. The predictions from the current method compare favourably with those by existing experimental, analytical and computational studies. The simple and explicit expressions of the interfacial stresses provide valuable analysis tools accessible to practical users.

Details

Engineering Computations, vol. 31 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 February 1986

Ola Dahlblom, Anders Peterson and Hans Petersson

A computer program, CALFEM, is presented. This interactive computer program is designed as a tool for teaching of the finite element method. No programming knowledge is…

Abstract

A computer program, CALFEM, is presented. This interactive computer program is designed as a tool for teaching of the finite element method. No programming knowledge is needed. The program is well suited to solve problems in structural mechanics and for solution of field problems. A variety of finite elements is available. One objective when designing CALFEM was that the user shall understand every part of the computational procedure. The program is based on a command language. All information is stored in user‐defined matrices created by usage of commands. Required input to matrices are given on request from the program. The contents of the matrices can be looked upon at any time and new decisions can be made in the course of the run. The user of the program determines in which way he wants to proceed with the calculation process by choosing proper commands. This means that everything in the computational procedure is under the direct control of the user. This is in contrast to many conventional ‘black box’ finite element programs. Commands can be stored on user‐defined secondary storage files. The files can be edited in CALFEM and be used further on in the calculation procedure. The program is written in FORTRAN 77 and all calculations are performed in double precision.

Details

Engineering Computations, vol. 3 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 February 1994

A.O.M. SALEH and M.A. LAUGHTON

A quantitative method for the estimation of the discrete transition matrix is developed for the periodic time‐varying system of state differential equations governing…

Abstract

A quantitative method for the estimation of the discrete transition matrix is developed for the periodic time‐varying system of state differential equations governing electrical synchronous machine behaviour. The approach allows the eigensystem of this transition matrix to be calculated to an arbitrary accuracy without significant added computational burden by using modal structural properties of the state‐space equations.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 13 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 1956

P.M. Hunt

This paper describes the use of preset and programme parameters with the matrix interpretive scheme (which was considered in Part I) for the preparation of general purpose…

Abstract

This paper describes the use of preset and programme parameters with the matrix interpretive scheme (which was considered in Part I) for the preparation of general purpose programmes for an electronic digital computer. The implications of partitioning the matrices when using the force method of analysis are considered in detail and the above techniques are applied to develop general purpose programmes for the calculations encountered when using this method of structural analysis. The general case, when all matrices are partitioned; the displacement method of structural analysis, and the use of magnetic tape storage, are considered in Part III.

Details

Aircraft Engineering and Aerospace Technology, vol. 28 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 February 2002

Daniel F. Twomey

Organization structures are as important to competitiveness as strategy because structures enable both performance and learning. Yet, organization design factors and…

Abstract

Organization structures are as important to competitiveness as strategy because structures enable both performance and learning. Yet, organization design factors and considerations are often overlooked. The matrix structure and similar types of adhocracies have the potential to transform organizational learning and thereby create a continuous acceleration of innovation. Unlike some adhocracies, the matrix structure focuses on performance and learning. Because of deficiencies in organization culture and management skills, the matrix structure has been less than fully effective. This paper seeks to clarify the issues that continue to block organizational competitiveness as they relate to performance and learning in matrix structures.

Details

Competitiveness Review: An International Business Journal, vol. 12 no. 2
Type: Research Article
ISSN: 1059-5422

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