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Article
Publication date: 4 June 2020

Tiago Oliveira, Wilber Vélez and Artur Portela

This paper is concerned with new formulations of local meshfree and finite element numerical methods, for the solution of two-dimensional problems in linear elasticity.

Abstract

Purpose

This paper is concerned with new formulations of local meshfree and finite element numerical methods, for the solution of two-dimensional problems in linear elasticity.

Design/methodology/approach

In the local domain, assigned to each node of a discretization, the work theorem establishes an energy relationship between a statically admissible stress field and an independent kinematically admissible strain field. This relationship, derived as a weighted residual weak form, is expressed as an integral local form. Based on the independence of the stress and strain fields, this local form of the work theorem is kinematically formulated with a simple rigid-body displacement to be applied by local meshfree and finite element numerical methods. The main feature of this paper is the use of a linearly integrated local form that implements a quite simple algorithm with no further integration required.

Findings

The reduced integration, performed by this linearly integrated formulation, plays a key role in the behavior of local numerical methods, since it implies a reduction of the nodal stiffness which, in turn, leads to an increase of the solution accuracy and, which is most important, presents no instabilities, unlike nodal integration methods without stabilization. As a consequence of using such a convenient linearly integrated local form, the derived meshfree and finite element numerical methods become fast and accurate, which is a feature of paramount importance, as far as computational efficiency of numerical methods is concerned. Three benchmark problems were analyzed with these techniques, in order to assess the accuracy and efficiency of the new integrated local formulations of meshfree and finite element numerical methods. The results obtained in this work are in perfect agreement with those of the available analytical solutions and, furthermore, outperform the computational efficiency of other methods. Thus, the accuracy and efficiency of the local numerical methods presented in this paper make this a very reliable and robust formulation.

Originality/value

Presentation of a new local mesh-free numerical method. The method, linearly integrated along the boundary of the local domain, implements an algorithm with no further integration required. The method is absolutely reliable, with remarkably-accurate results. The method is quite robust, with extremely-fast computations.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 11 October 2011

Rabe Alsafadie, Mohammed Hjiaj, Hugues Somja and Jean‐Marc Battini

The purpose of this paper is to present eight local elasto‐plastic beam element formulations incorporated into the corotational framework for two‐noded three‐dimensional…

Abstract

Purpose

The purpose of this paper is to present eight local elasto‐plastic beam element formulations incorporated into the corotational framework for two‐noded three‐dimensional beams. These formulations capture the warping torsional effects of open cross‐sections and are suitable for the analysis of the nonlinear buckling and post‐buckling of thin‐walled frames with generic cross‐sections. The paper highlights the similarities and discrepancies between the different local element formulations. The primary goal of this study is to compare all the local element formulations in terms of accuracy, efficiency and CPU‐running time.

Design/methodology/approach

The definition of the corotational framework for a two‐noded three‐dimensional beam element is presented, based upon the works of Battini .The definitions of the local element kinematics and displacements shape functions are developed based on both Timoshenko and Bernoulli assumptions, and considering low‐order as well as higher‐order terms in the second‐order approximation of the Green‐Lagrange strains. Element forces interpolations and generalized stress resultant vectors are then presented for both mixed‐based Timoshenko and Bernoulli formulations. Subsequently, the local internal force vector and tangent stiffness matrix are derived using the principle of virtual work for displacement‐based elements and the two‐field Hellinger‐Reissner assumed stress variational principle for mixed‐based formulations, respectively. A full comparison and assessment of the different local element models are performed by means of several numerical examples.

Findings

In this study, it is shown that the higher order elements are more accurate than the low‐order ones, and that the use of the higher order mixed‐based Bernoulli element seems to require the least number of FEs to accurately model the structural behavior, and therefore allows some reduction of the CPU time compared to the other converged solutions; where a larger number of elements are needed to efficiently discretize the structure.

Originality/value

The paper reports computation times for each model in order to assess their relative efficiency. The effect of the numbers of Gauss points along the element length and within the cross‐section are also investigated.

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Article
Publication date: 19 March 2018

Joshua Osah and Caroline Khene

This study aims to identify group structural elements that should be assessed in e-Government strategy formulation processes at local government level for service delivery…

Abstract

Purpose

This study aims to identify group structural elements that should be assessed in e-Government strategy formulation processes at local government level for service delivery in South Africa. These elements influence the success or effectiveness of the strategy formulation process.

Design/methodology/approach

The theoretical framework of group structural elements by Asplund and nine other strategy formulation-related approaches are reflected upon. Weick’s approach of theory development is used to guide the theoretical analysis. A pragmatic approach is applied to conduct the empirical investigation using a case study of a digital citizen engagement project in South Africa.

Findings

The paper highlights the following group elements that influence the strategy formulation process: group member relations, degree of differentiation within the group and resources of the group. Not addressing these structural elements may result in a lack of creativity or a reluctance to participate in the context of public sector engagement.

Research limitations/implications

The paper does not provide an exhaustive list of all aspects that necessitate assessment before and during a strategy formulation process, for example, organisational and environment structural elements.

Practical implications

Assessing group structural elements provides valuable knowledge on how to engage stakeholders in a joint problem-solving activity. This is particularly pertinent where citizen engagement is fundamental to addressing basic service delivery concerns.

Originality/value

In the South African local municipal context, there is no existing literature that discusses the need to assess group structural elements influencing the outcome of an e-Government strategy formulation process.

Details

Transforming Government: People, Process and Policy, vol. 12 no. 1
Type: Research Article
ISSN: 1750-6166

Keywords

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Article
Publication date: 1 February 1988

Gilles Pijaudier‐Cabot, Zdeněk P. Bažant and Mazen Tabbara

This paper presents a comparison of various models for strain‐softening due to damage such as cracking or void growth, as proposed recently in the literature…

Abstract

This paper presents a comparison of various models for strain‐softening due to damage such as cracking or void growth, as proposed recently in the literature. Continuum‐based models expressed in terms of softening stress—strain relations, and fracture‐type models expressed in terms of softening stress—displacement relations are distinguished. From one‐dimensional wave propagation calculations, it is shown that strain‐localization into regions of finite size cannot be achieved. The previously well‐documented spurious convergence is obtained with continuum models, while stress—displacement relations cannot model well smeared‐crack situations. Continuum models may, however, be used in general if a localization limiter is implemented. Gradient‐type localization limiters appear to be rather complicated; they require solving higher‐order differential equations of equilibrium with additional bourdary conditions. Non‐local localization limiters, especially the non‐local continuum with local strain, in which only the energy dissipating variables are non‐local, is found to be very effective, and also seems to be physically realistic. This formulation can correctly model the transition between homogeneous damage states and situations in which damage localizes into small regions that can be viewed as cracks. The size effect observed in the experimental and numerical response of specimens in tension or compression is shown to be a consequence of this progressive transition from continuum‐type to fracture‐type formulations.

Details

Engineering Computations, vol. 5 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 March 2007

Francois K. Doamekpor

Government fiscal officers, practitioners and policy makers constantly deal with uncertainties in revenue and expenditure projections. These uncertainties create…

Abstract

Government fiscal officers, practitioners and policy makers constantly deal with uncertainties in revenue and expenditure projections. These uncertainties create difficulties in resource allocation decisions when significant deviations occur. Clearly, certain variables account for these uncertainties and knowing them prior to revenue and expenditure planning may minimize potentials for errors. This study seeks to determine the identities and reliability of these variables through the application of a measurement model to aggregate data under the formulation that certain variables create uncertainties and affect significantly both revenues and expenditures of state and local governments. The results reveal that inflation, population, unemployment rate, time, government bond rate, and real long-term debts per capita are the most reliable indicators of both revenues and expenditures.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 19 no. 1
Type: Research Article
ISSN: 1096-3367

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Article
Publication date: 1 September 2005

J.G. Wang, L. Yan and G.R. Liu

Develop a local radial point interpolation method (LRPIM) to analyze the dissipation process of excess pore water pressure in porous media and verify its numerical capability.

Abstract

Purpose

Develop a local radial point interpolation method (LRPIM) to analyze the dissipation process of excess pore water pressure in porous media and verify its numerical capability.

Design/methodology/approach

Terzaghi's consolidation theory is used to describe the dissipation process. A local residual form is formulated over only a sub‐domain. This form is spatially discretized by radial point interpolation method (RPIM) with basis of multiquadrics (MQ) and thin‐plate spline (TPS), and temporally discretized by finite difference method. One‐dimensional (1D) and two‐dimensional consolidation problems are numerically analyzed.

Findings

The LRPIM is suitable, efficient and accurate to simulate this dissipation process. The shape parameters, q=1.03, R=0.1 for MQ and η=4.001 for TPS, are still valid.

Research limitations/implications

The asymmetric system matrix in LRPIM spends more resources in storage and CPU time.

Practical implications

Local residual form requires no background mesh, thus being a truly meshless method. This provides a fast and practical algorithm for engineering computation.

Originality/value

This paper provides a simple, accurate and fast numerical algorithm for the dissipation process of excess pore water pressure, largely simplifies data preparation, shows that the shape parameters from solid mechanics are also suitable for the dissipation process.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 15 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 4 November 2019

E.J. Sellountos, Jorge Tiago and Adelia Sequeira

This paper aims to describe the 2D meshless local boundary integral equation (LBIE) method for solving the Navier–Stokes equations.

Abstract

Purpose

This paper aims to describe the 2D meshless local boundary integral equation (LBIE) method for solving the Navier–Stokes equations.

Design/methodology/approach

The velocity–vorticity formulation is selected to eliminate the pressure gradient of the equations. The local integral representations of flow kinematics and transport kinetics are derived. The integral equations are discretized using the local RBF interpolation of velocities and vorticities, while the unknown fluxes are kept as independent variables. The resulting volume integrals are computed using the general radial transformation algorithm.

Findings

The efficiency and accuracy of the method are illustrated with several examples chosen from reference problems in computational fluid dynamics.

Originality/value

The meshless LBIE method is applied to the 2D Navier–Stokes equations. No derivatives of interpolation functions are used in the formulation, rendering the present method a robust numerical scheme for the solution of fluid flow problems.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 1 April 1998

K.E. Dickson and A. Hadjimanolis

The practice of innovation management in Cyprus is investigated via case studies of innovative small manufacturing firms. The analysis concentrates on how Cypriot firms…

Abstract

The practice of innovation management in Cyprus is investigated via case studies of innovative small manufacturing firms. The analysis concentrates on how Cypriot firms develop networks (or avoid them!) and the effects of network relationships on innovation performance. The behaviour of firms is related to two contrasting models of network development: First, the “local strategic network model” where firms intentionally develop and maintain a network of long‐term relationships based on trust, cooperation and mutual benefit, with a view to obtaining the necessary resources and knowledge for innovation. Second, the “local self sufficiency model” where firms obtain any required resources from other local firms through ‘arms length’ market based transactions and any technical knowledge primarily from foreign suppliers. Such firms follow an insular pattern of behaviour in order to protect their independence and innovative activities. The possible association between performance (in terms of profitability, sales growth) and innovation strategies of Cypriot firms is examined and the implications for business managers and for Government support programmes are drawn out.

Details

International Journal of Entrepreneurial Behavior & Research, vol. 4 no. 1
Type: Research Article
ISSN: 1355-2554

Keywords

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Case study
Publication date: 16 April 2015

Rozhan Abu Dardak and Farzana Quoquab

New product development (NPD), entrepreneurship and strategic management.

Abstract

Subject area

New product development (NPD), entrepreneurship and strategic management.

Study level/applicability

Advanced undergraduate, MBA/MSc in Marketing and Management course that cover the topics on NPD.

Case overview

This case illustrates that commercialization of a new product requires a proper strategic direction to make it a reality. The case fact is positioned in livestock feed industry centered on commercialization of a newly developed urea-molasses mineral block (UMMB) or called Nutriblock. Dr Wan, a Senior Principal Research Officer of Malaysian Agricultural Research and Development Institute (MARDI), developed food supplement for ruminants which contained urea, molasses, vitamins, minerals and other nutrients. Dr Wan believed that the UMMB was a better quality food supplement compared to products in the markets because it contained 12 raw feed ingredients and an anthelmintic medication. After almost 10 years of research, in 2003, Dr Wan completed his research and, thus, wanted to get a suitable way to commercialize this product. He had two options: commercializing the technology through licensing of intellectual property right (IPR), or to transfer it as a public domain. The Business Development Unit(BDU) was responsible for the former option, whereas Centre for Promotion and Technology Transfer (CPPT) was in charge for the latter. At the beginning of2006, MARDI decided to commercialize the Nutriblock through licensing the IPR to March Avenue Technology Sendirian Berhad (March Avenue), a newly formed company. March Avenue was formed byKarthiir, a lawyer and Ma Irwan, an electrical engineer. The operation was going smoothly for the first two years. However, problem started in 2008 when Karthiir left the company due to some disagreement with Ma Irwan. Since then, March Avenue failed to achieve its sales target that seriously affected its profit level. Moreover, it suffered from internal management problem. The company finally closed down at the end of 2009. By this four year of operation, March Avenue failed to pay any royalty to MARDI. This circumstance forced Dr Wan to think seriously about his next move regarding choosing the right way of commercializing his Nutriblock. MARDI requested him to give his opinion by January 15, 2010 about whether to give another chance to BDU to commercialize this technology through IPR or to go for public domain under CPPT?

Expected learning outcomes

Using this case, students can learn that new product development and its commercialization requires proper strategic directions. It illustrates the importance of managing the commercialization of a new product effectively. NPD involves many stages, and it is important to manage every stage properly. This is because a “high-quality product” and/or a “new to the market” product are not enough to succeed in the market. In other words, producing a “product that meets market needs” must be combined with appropriate strategies.

Supplementary materials

Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Details

Emerald Emerging Markets Case Studies, vol. 5 no. 2
Type: Case Study
ISSN: 2045-0621

Keywords

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Article
Publication date: 1 December 1997

J.‐P. CIech

This paper presents a solder joint engineering reliability model —Solder Reliability Solutions** (SRS) — and its application to surface mountarea‐array and chip‐scale…

Abstract

This paper presents a solder joint engineering reliability model — Solder Reliability Solutions** (SRS) — and its application to surface mount area‐array and chip‐scale assemblies. The model is validated by failure data from 33 accelerated thermal cycling tests, and test vehicles covering several generations of component, assembly and circuit board technologies and a variety of test conditions. The SRS model has been implemented as a PC‐based design‐for‐reliabilltytool that enables rapid assessment of assembly reliability in the early stages of product development.

Details

Soldering & Surface Mount Technology, vol. 9 no. 2
Type: Research Article
ISSN: 0954-0911

Keywords

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