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Article
Publication date: 6 November 2023

Daniel E.S. Rodrigues, Jorge Belinha and Renato Natal Jorge

Fused Filament Fabrication (FFF) is an extrusion-based manufacturing process using fused thermoplastics. Despite its low cost, the FFF is not extensively used in high-value…

44

Abstract

Purpose

Fused Filament Fabrication (FFF) is an extrusion-based manufacturing process using fused thermoplastics. Despite its low cost, the FFF is not extensively used in high-value industrial sectors mainly due to parts' anisotropy (related to the deposition strategy) and residual stresses (caused by successive heating cycles). Thus, this study aims to investigate the process improvement and the optimization of the printed parts.

Design/methodology/approach

In this work, a meshless technique – the Radial Point Interpolation Method (RPIM) – is used to numerically simulate the viscoplastic extrusion process – the initial phase of the FFF. Unlike the FEM, in meshless methods, there is no pre-established relationship between the nodes so the nodal mesh will not face mesh distortions and the discretization can easily be modified by adding or removing nodes from the initial nodal mesh. The accuracy of the obtained results highlights the importance of using meshless techniques in this field.

Findings

Meshless methods show particular relevance in this topic since the nodes can be distributed to match the layer-by-layer growing condition of the printing process.

Originality/value

Using the flow formulation combined with the heat transfer formulation presented here for the first time within an in-house RPIM code, an algorithm is proposed, implemented and validated for benchmark examples.

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Article
Publication date: 1 April 1994

J. Noorzaei, M.N. Viladkar and P.N. Godbole

Study of soil‐structure interaction effect in framed structuresnecessitates proper physical modelling of the structure, foundation and thesoil mass. At the same time, the…

136

Abstract

Study of soil‐structure interaction effect in framed structures necessitates proper physical modelling of the structure, foundation and the soil mass. At the same time, the stress—strain model used for the constitutive relationship of the soil mass must also be realistic. In the present study, a hyperbolic stress—strain model has been used to consider the soil non‐linearity. The interactive behaviour of a five storey, two bay plane frame has been studied in detail and the results are compared with those obtained from a conventional and a linear interactive analysis.

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Engineering Computations, vol. 11 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 January 1992

N. SOYRIS, L. FOURMENT, T. COUPEZ, J.P. CESCUTTI, G. BRACHOTTE and J.L. CHENOT

This paper presents the results of the simulation of the forging of a connecting rod. The calculation has been carried out by the code FORGE3 developed at the CEMEF laboratory…

169

Abstract

This paper presents the results of the simulation of the forging of a connecting rod. The calculation has been carried out by the code FORGE3 developed at the CEMEF laboratory. FORGE3 is a three‐dimensional finite element computer program that can simulate hot forging of industrial parts. The flow problem is solved using a thermomechanical analysis. The mechanical resolution and the thermal one are coupled by the way of the consistency K which is thermodependent, the plastic deformation in the volume of the material and the friction heat flux on the surface. The material behaviour is assumed to be incompressible and viscoplastic (Norton—Hoff law) with the associated friction law. The thermal resolution includes the case of non‐linear physical properties and boundary conditions. An explicit Euler scheme is used for the mechanical resolution and two‐step schemes for the thermal one. For the computation of other parameters, it is necessary to have a good approximation for the strain rate tensor. The Orkisz method has been used to determine the deviatoric stress tensor and p is calculated by an original smoothing method. The results show that it is possible to get good information on the flow and on the physical properties during forging of automotive parts. Comparisons have been made with experimental measurements with a reasonably good agreement.

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Engineering Computations, vol. 9 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 March 1996

Jean‐Loup Chenot, E. Massoni and JL. Fourment

Focuses on the inverse problems arising from the simulation of forming processes. Considers two sets of problems: parameter identification and shape optimization. Both are solved…

417

Abstract

Focuses on the inverse problems arising from the simulation of forming processes. Considers two sets of problems: parameter identification and shape optimization. Both are solved using an optimization method for the minimization of a suitable objective function. The convergence and convergence rate of the method depend on the accuracy of the derivatives of this function. The sensitivity analysis is based on a discrete approach, e.g. the differentiation of the discrete problem equations. Describes the method for non‐linear, non‐steady‐state‐forming problems involving contact evolution. First, it is applied to the parameter identification and to the torsion test. It shows good convergence properties and proves to be very efficient for the identification of the material behaviour. Then, it is applied to the tool shape optimization in forging for a two‐step process. A few iterations of the inverse method make it possible to suggest a suitable shape for the preforming tools.

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Engineering Computations, vol. 13 no. 2/3/4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 January 1988

J.L. Chenot

The constitutive equations for the deformation of elastoplastic, viscoplastic or compressible materials are presented for the small strain approximation and for the large strain…

56

Abstract

The constitutive equations for the deformation of elastoplastic, viscoplastic or compressible materials are presented for the small strain approximation and for the large strain theory of Hill. A velocity approach is proposed for time discretization, which leads to a second order approximation for small strain, and an incrementally objective second order approximation for large deformation processes. Two other quasi second order formulations are discussed. The finite element space discretization is outlined and the solution procedure is described.

Details

Engineering Computations, vol. 5 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 February 1998

Hiroshi Okuda, Shinobu Yoshimura, Genki Yagawa and Akihiro Matsuda

Describes the parameter estimation procedures for the non‐linear finite element analysis using the hierarchical neural network. These procedures can be classified as the neural…

582

Abstract

Describes the parameter estimation procedures for the non‐linear finite element analysis using the hierarchical neural network. These procedures can be classified as the neural network based inverse analysis, which has been investigated by the authors. The optimum values of the parameters involved in the non‐linear finite element analysis are generally dependent on the configuration of the analysis model, the initial condition, the boundary condition, etc., and have been determined in a heuristic manner. The procedures to estimate such multiple parameters consist of the following three steps: a set of training data, which is produced over a number of non‐linear finite element computations, is prepared; a neural network is trained using the data set; the neural network is used as a tool for searching the appropriate values of multiple parameters of the non‐linear finite element analysis. The present procedures were tested for the parameter estimation of the augmented Lagrangian method for the steady‐state incompressible viscous flow analysis and the time step evaluation of the pseudo time‐dependent stress analysis for the incompressible inelastic structure.

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Engineering Computations, vol. 15 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 January 1993

G.S. SEKHON and J.L. CHENOT

A finite element model for numerical simulation of non‐steady but continuous chip formation under orthogonal cutting conditions is described. The problem is treated as coupled…

475

Abstract

A finite element model for numerical simulation of non‐steady but continuous chip formation under orthogonal cutting conditions is described. The problem is treated as coupled thermo‐mechanical. A velocity approach has been adopted for the proposed solution. The computational algorithm takes care of dynamic contact conditions and makes use of an automatic remeshing procedure. The results of simulation yield complete history of chip initiation and growth as well as distributions of strain rate, strain, stress and temperature. The paper includes a detailed presentation of computational results for an illustrative case.

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Engineering Computations, vol. 10 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 March 1990

François Bay and Jean‐Loup Chenot

In order to optimize production and save material, numerical simulation is becoming more and more used in industrial forging processes.

54

Abstract

In order to optimize production and save material, numerical simulation is becoming more and more used in industrial forging processes.

Details

Engineering Computations, vol. 7 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 February 1998

Jyoti Lata Pandey and M.K. Banerjee

Concrete forms a major component of the national infrastructure. Corrosion of reinforced steels embedded in concrete has recently received wide attention in R&D programmes…

1590

Abstract

Concrete forms a major component of the national infrastructure. Corrosion of reinforced steels embedded in concrete has recently received wide attention in R&D programmes. Different cases have been reported showing failures of concrete structures which means huge loss. An attempt has been made to identify the different factors affecting the corrosion of embedded steel. Comparative evaluation of different protective schemes use of additives in concrete admixtures and the application of the cathodic protection technique has been discussed.

Details

Anti-Corrosion Methods and Materials, vol. 45 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Available. Content available
Book part
Publication date: 12 October 2018

Abstract

Details

Quality Services and Experiences in Hospitality and Tourism
Type: Book
ISBN: 978-1-78756-384-1

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