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Article
Publication date: 1 April 1984

W. Lambert

The reasons for the essential drying of electronic components are enumerated prior to a description of several drying methods currently employed in industry. A process…

Abstract

The reasons for the essential drying of electronic components are enumerated prior to a description of several drying methods currently employed in industry. A process involving drying with fluorocarbons that utilises a water displacement system is found to perform efficiently. The displacement effect is outlined and the benefits of using this system with fluorocarbon solvents are listed. Various applications exist in the electronics field for which this method proves to offer marked advantages.

Details

Circuit World, vol. 11 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 5 August 2019

Wei-Hai Yuan, Wei Zhang, Beibing Dai and Yuan Wang

Large deformation problems are frequently encountered in various fields of geotechnical engineering. The particle finite element method (PFEM) has been proven to be a…

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Abstract

Purpose

Large deformation problems are frequently encountered in various fields of geotechnical engineering. The particle finite element method (PFEM) has been proven to be a promising method to solve large deformation problems. This study aims to develop a computational framework for modelling the hydro-mechanical coupled porous media at large deformation based on the PFEM.

Design/methodology/approach

The PFEM is extended by adopting the linear and quadratic triangular elements for pore water pressure and displacements. A six-node triangular element is used for modelling two-dimensional problems instead of the low-order three-node triangular element. Thus, the numerical instability induced by volumetric locking is avoided. The Modified Cam Clay (MCC) model is used to describe the elasto-plastic soil behaviour.

Findings

The proposed approach is used for analysing several consolidation problems. The numerical results have demonstrated that large deformation consolidation problems with the proposed approach can be accomplished without numerical difficulties and loss of accuracy. The coupled PFEM provides a stable and robust numerical tool in solving large deformation consolidation problems. It is demonstrated that the proposed approach is intrinsically stable.

Originality/value

The PFEM is extended to consider large deformation-coupled hydro-mechanical problem. PFEM is enhanced by using a six-node quadratic triangular element for displacement and this is coupled with a four-node quadrilateral element for modelling excess pore pressure.

Details

Engineering Computations, vol. 36 no. 9
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 February 1986

H.R. Thomas and C.H. Liu

The implementation of the finite element solution of Biot's consolidation theory on a low‐cost microcomputer is described. A two‐dimensional linear elastic model is solved…

Abstract

The implementation of the finite element solution of Biot's consolidation theory on a low‐cost microcomputer is described. A two‐dimensional linear elastic model is solved using bilinear rectangular elements and a fully implicit timestepping algorithm. The machine used is the Acorn Computers model B, BBC microcomputer, a popular low‐cost engineering applications machine. The program is written in Basic but to increase speed of computation certain sections of the solution procedure involving matrix manipulation are written in Assembly language. The results obtained are encouraging from the point of view of accuracy, problem size and computational time. It is concluded that there is scope for the use of the present generation of low‐cost microcomputer, as typified by this machine, in the numerical solution of the more straightforward, but still realistic, consolidation problems.

Details

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

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Article
Publication date: 1 July 1954

R. Leslie

Temporary corrosion preventives based on petroleum are applied to a great variety of products ranging from ball bearings to sheet steel to give protection during…

Abstract

Temporary corrosion preventives based on petroleum are applied to a great variety of products ranging from ball bearings to sheet steel to give protection during manufacture, transport or storage. In this article the author describes the main types of preventives, their selection for particular purposes, methods of application, the types of and mode of action of inhibitors added to the preventives and, finally, methods of testing.

Details

Anti-Corrosion Methods and Materials, vol. 1 no. 7
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 June 1951

A new range of mechanical lubricating equipment is now being manufactured in Great Britain. This is the result of an agreement between Davies & Metcalfe Ltd., Romiley…

Abstract

A new range of mechanical lubricating equipment is now being manufactured in Great Britain. This is the result of an agreement between Davies & Metcalfe Ltd., Romiley, Stockport, and Alex. Friedmann, Vienna. The latter company have manufactured high class mechanical lubricators and accessories for very many years and are well known in most parts of the world.

Details

Industrial Lubrication and Tribology, vol. 3 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 19 July 2019

Bingqi Li, Zhenyu Zhang, Xiaogang Wang and Xiaonan Liu

The behavior of joints has a significant effect on the stability of water conveyance tunnel. The purpose of this paper is to study the contact and friction at the joint of…

Abstract

Purpose

The behavior of joints has a significant effect on the stability of water conveyance tunnel. The purpose of this paper is to study the contact and friction at the joint of the tunneling segment lining and establish its contact friction model. At the same time, the stress and deformation characteristics at the joint of the segment under hydrostatic load are analyzed.

Design/methodology/approach

In this study, the contact and friction in a bolted joint are examined using shear testing. The feasibility of the proposed model is verified by a numerical simulation of tests and a theoretical analysis. Accordingly, the effect of joints on the lining is explored under internal hydrostatic loading.

Findings

The results show that the openings of tunnel segments in joints gradually expand from the positions of the inner and outer edges to the location of the bolt. Moreover, the stress concentration zone is formed at the bolt. Under hydraulic loading, the opening displacement at the joint increases as the water pressure increases; nevertheless, it does not exceed engineering requirements. When the water pressure of the tunnel lining joint reaches 0.5 MPa, the opening of the joint slowly increases. When the water pressure exceeds 0.7 MPa, the opening of the joint rapidly and significantly increases.

Originality/value

Contact and friction in a bolted joint were examined using shear testing. A cohesive zone model of bolted joints was proposed based on test results. The influence of joint behavior on the stability of water conveyance tunnel was studied.

Details

Engineering Computations, vol. 36 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 November 1996

Dariusz Gawin, Bernhard A. Schrefler and M. Galindo

Presents a fully coupled numerical model to simulate the slow transient phenomena involving heat and mass transfer in deforming partially saturated porous materials. Makes…

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Abstract

Presents a fully coupled numerical model to simulate the slow transient phenomena involving heat and mass transfer in deforming partially saturated porous materials. Makes use of the modified effective stress concept together with the capillary pressure relationship. Examines phase changes (evaporation‐condensation(, heat transfer through conduction and convection, as well as latent heat transfer. The governing equations in terms of gas pressure, capillary pressure, temperature and displacements are coupled non‐linear differential equations and are discretized by the finite element method in space and by finite differences in the time domain. The model is further validated with respect to a documented experiment on partially saturated soil behaviour, and the effects of two‐phase flow, as compared to the one‐phase flow solution, are analysed. Two other examples involving drying of a concrete wall and thermoelastic consolidation of partially saturated clay demonstrate the importance of proper physical modelling and of appropriate choice of the boundary conditions.

Details

Engineering Computations, vol. 13 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 20 April 2015

Xiaona Chen and Jianping Wang

– The purpose of this paper is to explore a novel breast volume measuring method by mesh projection based on three-dimensional (3D) point cloud data.

Abstract

Purpose

The purpose of this paper is to explore a novel breast volume measuring method by mesh projection based on three-dimensional (3D) point cloud data.

Design/methodology/approach

Mesh projection method, a rapid and accurate method to calculate the volume of models described by triangular meshes, was transplanted to calculate breast volume based on 3D point cloud data derived from a [TC]2 3D scanner. A simple landmarking procedure was developed to decide breast boundary. Breast volumes derived from mesh projection method were compared to the results of water displacement by statistical analysis to validate its accuracy.

Findings

A novel breast volume measurement method is developed based on mesh projection method. By comparison of water displacement, mesh projection method is proved to be accurate to calculate breast volume. Furthermore, a simple and standard breast boundary landmarking procedure is established, which avoids the arbitrariness of the definition of breast boundary and improves the repetition of landmarking.

Practical implications

A simple and convenient tool is provided for bra industries to rapidly and accurately measure breast volume.

Originality/value

Mesh projection method is primarily applied to determine breast volume based on 3D point cloud data. Meanwhile, a simple and standard breast boundary landmarking procedure is put forward.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 6 April 2020

Annan Jiang, Shuai Zheng and Shanyong Wang

This paper aims at the problem of surrounding rock excavation damage zone of tunneling in the rich water region, this paper aims to propose a new seepage-stress-damage…

Abstract

Purpose

This paper aims at the problem of surrounding rock excavation damage zone of tunneling in the rich water region, this paper aims to propose a new seepage-stress-damage coupling model and studied the numerical algorithm. This reflects the characteristics of rock damage evolution, accompanied by plastic flow deformation and multi-field interaction.

Design/methodology/approach

First of all, rock elastoplastic damage constitutive model based on the Drucker–Prager criterion is established, the fully implicit return mapping algorithm is adopted to realize the numerical solution. Second, based on the relation between damage variation and permeability coefficient, the rock stress-seepage-damage model and multi-field coupling solving iterative method are presented. Finally, using the C++ language compiled the corresponding programs and simulated tunnel engineering in the rich water region.

Findings

Results show that difference evolution-based back analysis inversed damage parameters well, at the same time the established coupling model and calculating program have more advantages than general conventional methods. Multiple field coupling effects should be more considered for the design of tunnel support.

Originality/value

The proposed method provides an effective numerical simulation method for the construction of the tunnel and other geotechnical engineering involved underground water problems.

Details

Engineering Computations, vol. 37 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 June 1995

Bernard A. Schrefler, Xiaoyong Zhan and Luciano Simoni

A fully coupled numerical model to simulate the complexbehaviour of soil deformation, water flow, airflow, and heatflow in porous media is developed. The following thermal…

Abstract

A fully coupled numerical model to simulate the complex behaviour of soil deformation, water flow, airflow, and heat flow in porous media is developed. The following thermal effects are taken into account: heat transfer through conduction and convection, flow, as well as viscosity and density variation of the fluids due to temperature gradients. The governing equations in terms of soil displacements, water and air pressures, and temperature are coupled non‐linear partial differential equations and are solved by the finite element method. Two examples are presented to demonstrate the model performances.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 5 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

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