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Article
Publication date: 4 November 2014

Mica Grujicic, Ramin Yavari, Jennifer Snipes, S. Ramaswami and Roshdy Barsoum

The purpose of this paper is to study the mechanical response of polyurea, soda-lime glass (glass, for short), polyurea/glass/polyurea and glass/polyurea/glass sandwich…

Abstract

Purpose

The purpose of this paper is to study the mechanical response of polyurea, soda-lime glass (glass, for short), polyurea/glass/polyurea and glass/polyurea/glass sandwich structures under dynamic-loading conditions involving propagation of planar longitudinal shockwaves.

Design/methodology/approach

The problem of shockwave generation, propagation and interaction with material boundaries is investigated using non-equilibrium molecular dynamics. The results obtained are used to construct basic shock Hugoniot relationships associated with the propagation of shockwaves through a homogeneous material (polyurea or glass, in the present case). The fidelity of these relations is established by comparing them with their experimental counterparts, and the observed differences are rationalized in terms of the microstructural changes experienced by the shockwave-swept material. The relationships are subsequently used to predict the outcome of the interactions of shockwaves with polyurea/glass or glass/polyurea material boundaries. Molecular-level simulations are next used to directly analyze the same shockwave/material-boundary interactions.

Findings

The molecular-level simulations suggested, and the subsequent detailed microstructural analyses confirmed, the formation of topologically altered interfacial regions, i.e. polyurea/glass and glass/polyurea interphases.

Originality/value

To the authors’ knowledge, the present work is a first attempt to analyze, using molecular-level simulation methods, the interaction of shockwaves with material boundaries.

Details

Multidiscipline Modeling in Materials and Structures, vol. 10 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 6 August 2018

Kindness A.M. Uyanga, Modestus Okechukwu Okwu, A.O. Adeoye and S.E. Ogbeide

The study aims to carry out the production of a bulk heterojunction organic solar cell in a laboratory scale using a blend of poly (3-hexylthiopene) (P3HT) and [6…

Abstract

Purpose

The study aims to carry out the production of a bulk heterojunction organic solar cell in a laboratory scale using a blend of poly (3-hexylthiopene) (P3HT) and [6, 6]-phenyl (C61) butyric acid methyl ether (PCBM).

Design/methodology/approach

Four inverted geometry organic solar cells were prepared based on 1:1 ratio of P3HT to PCBM and subjected to post annealing at different temperatures of 32, 120, 130 and 140°C. Solar cells were fabricated with structure glass/ITO/P3HT:PCBM/PEDOT:PSS/Au and characterized using Keithley 2400 series sourcemeter and a multimeter interfaced to a computer system with a LabVIEW software, which showed both dark and illumination current–voltage characteristic curves. Four reference cells were also fabricated with structure soda lime glass/P3HT:PCBM and annealed at different temperatures of 32, 120, 130 and 140°C.

Findings

The third organic solar cell prepared, Sample CITO, had the best performance with power conversion efficiency (PCE) of 2.0281 per cent, fill factor (FF) of 0.392, short circuit current of −0.0133 A and open circuit voltage of 0.389 V. Annealing of active layer was found to improve cell morphology, FF and PCE. Annealing of the active layer at 140°C resulted in a decrease of the PCE to 2.01 per cent.

Research limitations/implications

These findings are in good agreement with previous investigation in literature which reported that best annealing temperature for a 1:1 ratio blend of active material is 130°C. Ultraviolet–visible spectra on reference cells showed that sample CITO had wider absorption spectra with peak absorbance at a wavelength of 508 nm.

Originality/value

This research is purely original.

Details

World Journal of Engineering, vol. 15 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 1 August 1999

Jaroslav Mackerle

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the…

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Abstract

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Details

Engineering Computations, vol. 16 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 April 2005

Jaroslav Mackerle

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming…

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5057

Abstract

Purpose

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

Design/methodology/approach

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Findings

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Originality/value

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

Details

Engineering Computations, vol. 22 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 December 1964

G.W. Underwood

SUMMARY The main overall problems associated with transparencies for manned supersonic and hypersonic aircraft are considered. Civil and military concepts are compared in…

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51

Abstract

SUMMARY The main overall problems associated with transparencies for manned supersonic and hypersonic aircraft are considered. Civil and military concepts are compared in relation to aircraft performance requirements and the reasons for the continuing need for optical transparencies are enumerated. Aircraft performance requirements and typical flight plans show the necessity for designing the transparencies to withstand a considerable range of environmental conditions in addition to the aerodynamic dictates in relation to size, position and shape. These conditions are listed and design feature considerations are discussed in some detail with particular accent on the thermal problems. Reference is made to certain organic and inorganic materials for the basic glazings and the problems associated with the ‘marrying’ of these materials with retaining frame members are discussed. Detail proposals are made for typical windscreen and canopy assemblies. Brief reference is made to the poor reliability shown by many transparencies in present‐day modern aircraft which indicates the need for revision of certain existing test requirements. The proposed new requirements will result in the development of new testing techniques although test factors might well be reduced. The paper concludes with a statement on the importance which is being given to the subject matter by the various bodies in the U.K. and the emphasis which should be placed on the need for the continuation of research and development work in this field.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 12
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 23 February 2012

M. Suszynska, M. Szmida and A. Cizman

The aim of the work described was to investigate the effect of the glass microstructure, changed during chemical and thermal treatments, upon the micro-hardness and…

Abstract

The aim of the work described was to investigate the effect of the glass microstructure, changed during chemical and thermal treatments, upon the micro-hardness and microcracking of the exchanged specimens. Commercially available soda-lime silicate glass samples have been doped with copper. After ion-exchange, some of the specimens were annealed in the hydrogen atmosphere. Transmission electron microscopy, the XRD and electron diffraction techniques were used to characterize the microstructure of the glass-composites. Additionally, the linear thermal expansion coefficient was measured. The detected strengthening effects have been explained by supposing the formation of copper oxide and some mixed sodium-copper silicates. The induced decrease of the thermal expansion coefficient of this layer results in the formation of strong compressive stresses.

Details

World Journal of Engineering, vol. 9 no. 2
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 December 1964

A.F. Shoemaker

The factors which should be considered when contemplating windshield design are outlined, and various levels of high performance vehicles are defined. The relationship…

Abstract

The factors which should be considered when contemplating windshield design are outlined, and various levels of high performance vehicles are defined. The relationship between environment and design criteria is discussed and the author introduces some of the unique glasses in current use.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 12
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 December 1964

A.J. Holland

The construction of windscreen panels for modern aircraft is described and the role of each component in meeting the requirements for pressure strength, bird resistance…

Abstract

The construction of windscreen panels for modern aircraft is described and the role of each component in meeting the requirements for pressure strength, bird resistance and optical performance is discussed. The influence of the physical properties of the windscreen components on the performance of complete laminated windscreens is discussed and the limitations imposed by these properties indicated. Silicone inter‐layers are beginning to replace polyvinyl butyral inter‐layers in high‐speed aircraft laminated transparencies when the temperatures reached are above the working limit of the conventional interlayers. New types of glass capable of withstanding prolonged exposure to higher temperatures than soda lime silica glass without loss of toughening stress, and also capable of withstanding more severe thermal shock without fracture, have been developed.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 12
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 13 September 2011

V. Geža, A. Jakovičs, U. Krieger and B. Halbedel

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Abstract

Purpose

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Design/methodology/approach

Numerical calculations in ANSYS and ANSYS CFX were used to study electromagnetic, thermal, hydrodynamic and chemical mixing processes, results are validated by comparison with experimental data.

Findings

Obtained results show that investigated approach can improve glass melt chemical homogeneity significantly – Lorentz force driven melt movement in conjunction with diffusion process ensures good mixing quality.

Research limitations/implications

The mixing in glass melt is present only in azimuthal direction (in cylindrical coordinate system associated with outlet tube axis) but the radial homogenization is determined by diffusion only.

Practical implications

The experiments in JSJ GmbH with soda lime glass were successful and showed mixing effect in output material, thus providing additional method for glass production.

Originality/value

Although the electrical conductivity of glass is very low, the melt motion is generated by EM forces in this equipment, thus this approach is innovative in glass production technology where typical motion source is buoyancy or mechanical mixing.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 5
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 December 1964

P.W. Taylor

Three main subjects are presented in this paper: (i) A description of tests made for the purpose of determining design data; (ii) a discussion of the problems arising in…

Abstract

Three main subjects are presented in this paper: (i) A description of tests made for the purpose of determining design data; (ii) a discussion of the problems arising in the establishment of the approval procedures necessary to ensure safety and reliability; and (iii) a discussion of proposals for cyclic reliability tests. In the first section, tests to provide design data for glazing materials are described with particular emphasis placed on glasses. Types of specimen and apparatus for obtaining data at room temperature are mentioned and illustrations given of apparatus and specimens used in long term elevated temperature tests. In the second section, the overall level of reliability of complete components is discussed both in terms of structural safety and satisfactory service. While the current requirements have proved satisfactory for the past generation of aircraft, proposals are now put forward for patterns of testing that are more closely linked to the various design conditions now in use with both high‐speed and low‐speed aircraft, in order to place equal importance on the effects of temperature. In the third section, proposals are put forward for cyclic testing to overcome what appears to be an increasingly unsatisfactory record of reliability. The purpose of the tests is not to establish a safe life for any particular design but to reveal design deficiencies occurring from repeated applications of flight and thermal loadings.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 12
Type: Research Article
ISSN: 0002-2667

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