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1 – 10 of 53J.M.A. Cesar de Sa and D.R.J. Owen
The application of numerical techniques to the solution of practical problems which exist in rubber technology is described. Structures and components in the form of reinforced…
Abstract
The application of numerical techniques to the solution of practical problems which exist in rubber technology is described. Structures and components in the form of reinforced rubber shells are widely used in industry and prediction of their performance is complicated by both the anisotropic nature of composite construction and the incompressible behaviour of the basic material. A layered shell element is developed for the solution of such problems with general anisotropic behaviour independently permitted in each layer. The approach adopted permits the easy location of reinforcement patterns. Numerical solution is based on a single field formulation by eliminating at integrating point level the Lagrange multiplier imposing the incompressible constraint. Large deformation, including large rotation, behaviour is accommodated and a total Lagrangian solution process is adopted. The code developed permits the simulation of non‐conservative loading and its versatility is demonstrated by the solution of some practical examples.
Application of the finite element method to the simulation of glass forming processes is described. The forming process results in a coupled thermal/mechanical problem with…
Abstract
Application of the finite element method to the simulation of glass forming processes is described. The forming process results in a coupled thermal/mechanical problem with interaction between the heat transfer analysis of the temperature distribution in the glass and the viscous flow formulation describing the deformation of molten glass being a dominant factor. Particular attention must be given to derivation of the appropriate non‐linear thermal boundary conditions and also to monitoring of the mechanical contact between the glass and mould. The technique described provides both the glass and temperature distribution at each instant of the forming process and thus can provide invaluable information for mould and plunger design, optimum operation times, etc. Numerical examples are provided for both wide neck and narrow neck press and blow forming processes and the results obtained compare well with commercial observations.
R.J. Alves de Sousa, R.M. Natal Jorge, R.A. Fontes Valente and J.M.A. César de Sá
This paper focuses on the development of a new class of eight‐node solid finite elements, suitable for the treatment of volumetric and transverse shear locking problems. Doing so…
Abstract
This paper focuses on the development of a new class of eight‐node solid finite elements, suitable for the treatment of volumetric and transverse shear locking problems. Doing so, the proposed elements can be used efficiently for 3D and thin shell applications. The starting point of the work relies on the analysis of the subspace of incompressible deformations associated with the standard (displacement‐based) fully integrated and reduced integrated hexahedral elements. Prediction capabilities for both formulations are defined related to nearly‐incompressible problems and an enhanced strain approach is developed to improve the performance of the earlier formulation in this case. With the insight into volumetric locking gained and benefiting from a recently proposed enhanced transverse shear strain procedure for shell applications, a new element conjugating both the capabilities of efficient solid and shell formulations is obtained. Numerical results attest the robustness and efficiency of the proposed approach, when compared to solid and shell elements well‐established in the literature.
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J. César de Sá, Luisa Costa Sousa and Maria Luisa Madureira
Uses a rigid viscoplastic formulation to simulate hot and cold forging processes. The finite element solution uses mixed methods in which the independent variables can be…
Abstract
Uses a rigid viscoplastic formulation to simulate hot and cold forging processes. The finite element solution uses mixed methods in which the independent variables can be velocities, pressures and deviatoric stresses. Uses interface elements both in the mechanical and the thermal analysis, to take into account the effects of contact and friction, thermal conductivity of lubricants and heat generated by friction. The code developed includes an adaptive mesh refinement, triggered by an error estimator based on energy norms evaluated from nodal stress values, recovered from a local continuous polynomial expansion, and those given by the numerical solution. Assesses the code developed, using experimental results.
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José Antonio Pedraza-Rodríguez, Martha Yadira García-Briones and César Mora-Márquez
This article aims to explore the concept of chain value of the public port system in Ecuador from the perspective of importing/exporting companies, analyzing how perceived value…
Abstract
Purpose
This article aims to explore the concept of chain value of the public port system in Ecuador from the perspective of importing/exporting companies, analyzing how perceived value in the use of port services affects customer satisfaction and the intermediate links of the influence of trust and commitment on customer loyalty.
Design/methodology/approach
Relying on a survey of 634 Ecuadorian companies with experience in international trade as port users and a theoretical framework well-established in the literature on consumer behavior, the empirical study found evidence of a positive and significant relationship with the knowledge of chain effects.
Findings
The findings confirm the chain effect and reveal ways to maintain an ongoing satisfactory, trust and committed relationship with users, thereby ultimately gaining and maintaining their loyalty. The conclusions suggest how this postulate can help to close the gap referred to the effective management of port services, and point out that port managers should be concerned with a continuous in-depth understanding of the perceived value and its chain effects.
Originality/value
The authors add evidence of the use of the postulate of the chain of effects on these dimensions, whose applicability is very well established, tested and consensual for the doctrine in industrial marketing. In contrast, it is scarcely present in the port relationship with its users.
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Catarina F. Castro, Luísa Costa Sousa, C.A.C. António and J.M.A. César de Sá
An optimisation method for design of intermediate die shapes needed in some forging operations is presented. The basic problem consists of finding an optimal two‐step forging…
Abstract
An optimisation method for design of intermediate die shapes needed in some forging operations is presented. The basic problem consists of finding an optimal two‐step forging sequence by automatically designing the shape of the preforming tools. The optimisation problem is defined based on an inverse formulation. The objective function of the optimisation problem is a function describing the quality of the obtained part by measuring the die underfill. The finite element method is used to simulate the forging problem. The optimisation method is based on a modified sequential unconstrained minimisation technique and a gradient method. The sensitivity‐dependent algorithm requires computing the derivatives of the objective function with respect to the design variables defining the preform shapes. A direct differentiation method has been developed for this purpose. The optimisation scheme is demonstrated with two axisymmetric forging examples in which optimal preform dies are obtained.
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This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.
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Luís César Ferreira Motta Barbosa, Otávio José de Oliveira, Marcio Cardoso Machado, Ana Clara Tomaz Morais, Patrícia Maria Bozola and Manuel Gilberto Freitas Santos
This study used a qualitative approach on five case studies in Brazilian industrial companies. The research used interviews, document analysis and on-site visits to collect and…
Abstract
Purpose
This study used a qualitative approach on five case studies in Brazilian industrial companies. The research used interviews, document analysis and on-site visits to collect and analyze data. The companies were selected based on the following criteria: operating in the industrial sector, updating their quality management system (QMS) process to ISO 9001: 2015 and agreeing to participate in this study.
Design/methodology/approach
This article aims to investigate the strategies of industrial companies adopted for ISO-9001:2015 certification in light of the six major advances concerning the previous version. Thus, QMS of other organizations can incorporate identified lessons learned, whether certified or not.
Findings
The main finding of the research is the systematization of a set of lessons learned in the experiences of implementing the six significant advances of ISO 9001 concerning the previous version by industrial companies in the State of São Paulo in Brazil. These lessons can and should be used by other organizations to improve their QMSs.
Practical implications
The practices identified in this empirical research can serve as benchmarking to assist quality managers from other companies in QMS certification based on ISO 9001: 2015 or even those not certified but interested in updating their QMSs. Therefore, lessons learned can significantly minimize efforts to improve your projects, processes, products and services. These findings can also help industrial companies improve their production efficiency and effectiveness through quality improvement.
Originality/value
The main novelty of the research is the consolidation of theoretical and practical analysis of the main changes in the latest version of the ISO 9001 standards. The efforts to fulfill those changes result in lessons learned. The “lessons learned” will form a new block of knowledge that will subsidize theoretical (new research) and practical (formulation of a new ISO 9001 standard and helps quality managers improve their systems).
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This paper specifies how to construct and validate an instrument based on multi‐item scales for the cataloguing and measurement of managerial and organizational capabilities on…
Abstract
This paper specifies how to construct and validate an instrument based on multi‐item scales for the cataloguing and measurement of managerial and organizational capabilities on the basis of management perceptions. The construction and reduction of the scales have been reinforced by the Delphi and retesting techniques. The use of this methodology was illustrated in a sample of Spanish industrial firms. The paper enhances the value of the instruments for a resource‐based view with regard to the faithful and rigorous measurement of its key concept, distinctive competences. The scales created provide consistent empirical evidence to remove doubts surrounding managerial self‐evaluation, including those arising from problems of self‐esteem and reinforcement effects. In addition, the paper provides empirical evidence to support the predictive ability of distinctive competences on current and long‐term performance variability.
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