bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluoride-Containing Bioactive Glasses
Authors: Brauer Delia S. , Karpukhina Natalia , Seah Daphne , Law Robert V. , Hill Robert G.
Published: March 2009

Fluoride is an important mineral for hard tissues in the body and appropriate fluoride
exposure and usage are beneficial to bone and tooth integrity. Fluoride increases both bone density
and bone mass due to stimulation of bone formation and it is used as a treatment for osteoporosis.
Bioactive glasses have the capacity to form an intimate bond with living bone tissue due to
formation of a mixed hydroxycarbonate apatite layer (HCA) in vitro and in vivo. This makes
fluoride-containing bioactive glasses attractive biomaterials. In order to design fluoride-containing
bioactive glasses, we need to understand the role of fluorine within the glass structure.
A series of bioactive glasses with increasing fluoride content was prepared by a melt-quench route.
Characterisation included differential scanning calorimetry (DSC), density measurements, MASNMR
spectroscopy and studies in simulated body fluid (SBF).
DSC results showed a linear decrease in glass transition temperature (Tg) with increasing amounts
of fluoride. Density of the glasses increased with increasing amounts of fluoride. This may indicate
an expansion of the silicate glass network accompanying incorporation of CaF2. 19F MAS-NMR
spectroscopy showed broad peaks at chemical shifts between -135 and -120 ppm. As sodium
fluoride gives a chemical shift of -223 ppm and calcium fluoride of -108 ppm, this indicated
possible formation of mixed calcium sodium fluoride species. HCA and calcium phosphate layers
were found on the glasses after one week of immersion in SBF showing the bioactivity of the glass
series.
Liquids, Glasses, Density Fluctuations and Low Frequency Modes
Authors: Greaves G.N. , Wilding M.C. , Kargl F. , Hennet L.
Published: March 2009

An overview is given of recent advances in the experimental physics of supercooled
liquids and glasses. These are described in the context of measurements of non-ergodicity,
viscosity and low frequency dynamics. Particular attention is paid to recently reported
correlations between melt fragility and the vibrational and mechanical properties of the ensuing
glass. Low frequency vibrations are discussed in relation to the Boson peak that characterises
the glassy state. Throughout the over-arching role of density fluctuations in glass formation is
stressed together with the experimental tools now available to characterise heterogeneity.
Soda-Lime-Silica Glass Containers: Chemical Durability and Weathering Products
Authors: Chopinet Marie Helene , Verità M. , Falcone R. , Lehuédé P. , Vallotto M. , Nardone Michele , Sodo A.
Published: March 2009

In a previous paper the weathering of the internal surface of empty glass containers before
filling was investigated. Several phenomena were identified and described such as leaching of
modifiers, formation of a hydrated leached layer and of crystalline deposits mainly consisting of
Ca-carbonates and Na-carbonates. Localised glass surface corrosion was sometimes also detected.
The role of the storage conditions, time, temperature, relative humidity and concentrations of
pollutant gases (CO2, SO2), in the weathering phenomena was highlighted [1].
In the present work the composition of the weathered glass layer and the nature of the crystalline
deposits are investigated. Furthermore, in order to examine more closely the weathering
mechanisms and their causes, the correlation between durability laboratory tests and chemical
composition of soda-lime-silica glass are discussed.
Glass Surface Analysis by an Optimized Sequential Chemical Etching Technique Using the Corrosive Agent HF/HNO3
Authors: Djambazov Peter , Prange Andreas , Conradt Reinhard
Published: March 2009

The characterization of the early reaction steps of the corrosion process in liquid media
represents a tremendous challenge within the field of chemical analysis. In response to this, some
known instrumental methods like AFM, SIMS and SNMS have proven themselves useful. Within
the present work on the subject, we will introduce an optimized direct chemical etching technique
which allows the quantification of the primary removed glass surface layers. It is based on the
established etching procedure using hydrofluoric acid in combination with other mineral acids. The
above mentioned method is modified and appropriately extended by enhancing the precision of the
selected exposure time with the help of an automatic dipping device. Other improvements include
the minimization of the dissolution rate by lowering the test temperature to – 10°C and also the
decrease of the aqueous activity by adding alcohol instead of water into the acid solutions.
Furthermore, by applying sequential etching with low concetrations of HF and HNO3, very small
removal depths within the range below 10 nm per step are obtained. The equivalent components
from the dissolved surface layers of the examined float glass are determined by subsequent
chemical analysis of the etchants via AAS and ICP-OES. Their dissolution character can be well
distinguished through a comparison between the gravimetric mass loss qgravim and the so-called
normalized mass release per surface area qsol, calculated from the chemical composition of the
corrosive solutions.
Kinetics of E-glass Fibres Leaching in Borate Solution and Distilled Water
Authors: Mišíková Lucia , Liška Marek
Published: March 2009

Flow – through leaching experiments have been conducted on E – glass fibres in distilled
water and buffered potassium borate solution at temperatures 50, 70 and 90°C and at flow rates 8,
16 and 32 ml/hour. Time dependencies of normalized amount of leached elements in corrosive
solutions have been determined. Values of stationary leaching rates were calculated and values of
activation energies were found.
Ageing of Clay-Based Materials
Authors: Pešová Andrea , Andertová Jana , Machovič Vladimir , Gedeon Ondrej
Published: March 2009

One of the general symptoms of ageing is a volume change due to the moisture exposure,
known as an irreversible moisture expansion (IME). It is assumed IME of fired clay-based materials
is governed by the presence of inner-surface and interlamellar OH-groups, present in clay minerals
and assumed to be also abundant in amorphous intergranular phases. IME was measured on a series
of clay-based ceramic bodies with a variable content of clay raw minerals under two different
hydrothermal conditions. IR spectroscopy was used to correlate IME with the increasing amount of
inner and interlamellar hydroxyl groups.
Glass Formation in the MoO3-La2O3-Nd2O3 System
Authors: Aleksandrov Lyubomir , Iordanova Reni , Dimitriev Yanko B. , Handa Katsumi , Ide Junko , Milanova Margarita
Published: March 2009

Novel low melting glasses in the MoO3-La2O3-Nd2O3 system were obtained at different
cooling rates (102 K/s and 104-105 K/s). Characterization of the amorphous samples was made by
differential thermal analysis (DTA) and X-ray absorption fine structure (XAFS) method. According
to DTA data of the glass samples, the glass transition temperatures are at 325-330 0C, the
crystallization started above 410 0C and the melting temperatures are at 660-720 0C. A structural
model of glasses was suggested on the basis of XAFS and IR investigations. It was shown that the
predominant structural units in the amorphous network of glasses containing 90 -80 mol% MoO3
are MoO6 groups. The appearance of MoO4 groups deteriorates the glass formation ability.
Simulation of Electrical Heating with Multiple Transformers
Authors: Simons Philip , Habraken Andries
Published: March 2009

In the simulation package GTM-X two methods are available that approximate the
electric potentials in the glass melt in the presence of multiple transformers. Both methods control
the grouped electrodes in such a way that power consistency is guaranteed, also for complicated
electrode groupings and transformer systems. By power consistency we mean that the total heat
release, as calculated from the potentials and currents at the electrodes, matches the power that is
released in the volume cells. The first method approximates two scalar potentials; it may violate the
constraint that electrical currents are conserved per electrode group. The second method solves for
two scalar potentials per electrode group (or transformer); the result is that also this additional
constraint can be satisfied. In this article, we discuss these two methods and show results for a
model problem.
The Bubble Behaviour under Effect of Centrifugal Force
Authors: Tonarová Vladislava , Nĕmec Lubomír
Published: March 2009

The fining process may be enhanced by acting of additive force on bubbles in the glass
melt. This study deals with behaviour of single bubbles under effect of centrifugal force in a rotating
discontinuous cylinder with glass melt. The model of a single bubble in the combined gravitational
and centrifugal field has been set up and calculations of bubble behaviour in the cylinder have been
performed for the model TV glass. Two mechanisms of bubble separation were indicated from
results of calculations, i.e. the complete dissolution and separation by centrifugal force. The first
mechanism is restricted to areas close to cylinder mantel and exhibits relatively long bubble
dissolution times. The analysis of model and results revealed the potentially positive role of
increasing cylinder radius and partial filling of rotating cylinder with glass melt. The bubble
separation is considerably influenced by bubble dissolution or growth during centrifuging, thus the
crucial role in this process plays temperature and the bubble initial composition. The until now
results show that at lower temperatures the bubbles should contain low content of gases well soluble
in glass, to admit higher rotation velocities. Whereas to be enabled the transport of chemically
soluble gases from the melt into the bubbles at high temperatures, the bubbles have to be treated at
lower rotation velocities (ω =25 – 50 s-1). The small bubbles tend to dissolve close to the cylinder
mantle, but from other cylinder regions they have to be separated by centrifuging, and this is a very
slow process. Some pretreatments of the glass melt is considered to get rid of bubbles having size
under 0.1 mm.
Advanced Simulation of 3D Glass Bottle Forming with Abaqus
Authors: de Leede Gerard , Koch Rik , Bouwman Vincent , Kloosterman Gertjan
Published: March 2009

Production of glass bottles requires blowing of the glass after entrance of a gob of molten
glass in the blank mould. The final shape of the bottle is highly dependent on the viscosity of the
glass, the blow-pressure and the temperature distribution in the glass and the mould and simulation
of this complicated process enables optimization of the process conditions. During simulation of
blowing of the glass, the mesh has to be adapted due to the extreme deformations of the mesh. To
reduce the user-time and to be able to run this kind of analyses automatically based on an arbitrary
base-geometry, a completely automated remeshing/rezoning procedure is set-up. Using the
automated remeshing capability, simulations of the glass bottle forming process have successfully
been performed, enabling for example optimization of process settings.
Monitoring of Glass Production Using Vision Systems
Authors: Hotař Vlastimil
Published: March 2009

Applications of vision systems for control and monitoring are becoming more widespread.
However, there are still specific problems in the glass industry, especially transparency of glass
(many times colourless) that requires the use of special illuminations, adapters for lenses, filters,
software filters, analyses of images, etc. An important problem is the choice of an optimal analysis
for obtained images that should correspond with the character of obtained data. Our research is
developing the use of cameras (an area scan cameras, a line scan cameras, and an intelligent
cameras) for quality monitoring of glass production with connection to a PC or compact vision
systems, software solutions with appropriate image analyses (using standard and new algorithms)
and to solve of real problems for industry applications. The first stage of the research is: using a
digital camera, an area scan camera and a line scan camera for glass melt and glass products
monitoring to solve specific problems with lighting and to test some standard and non-standard
analysis such as fractal geometry for the evaluation of productions and products. This article briefly
shows basic information about our results and possibilities of application in the glass industry.
Properties of Glass Surface with Nano-Particles Aluminum Compounds Refined
Authors: Drajewicz Marcin , Wasylak Jan
Published: March 2009

New refining technology of soda – lime – silicon glassy surfaces with aluminum compounds
nano-molecules has been presented in the present study. Structural definition of aluminum
compounds nano-powders exposed to thermal processing, including grain-size analysis has been
discussed. Optimal technical and technological parameters of the refining process have been
selected. Refining method of soda – lime – silicon glassy surfaces with aluminum compounds nanomolecules
assures profitable operational properties of the glass, such as increased bending strength,
scratching strength, micro hardness and chemical resistance without deterioration of the optical
properties. Nano-molecules were spread onto the heated glass surface, or onto cold glass surface
and then heated up to temperatures close to the glass transformation, when nano-molecules
penetrate into the glass surface. The layer thicknes as glass operational properties has been tested.
From obtained results it can be explained the mechanism the incorporation of nano particles. The
received results develop new possibilities with respect to container glass, float glass and glass
fibres, as well as to glass processing.
Analysis of Tableware Mouth Impact Strength
Authors: Sabošová Janka , Vrábel Peter , Šajgalík Pavol
Published: March 2009

Mouth rim is a tableware quality issue perceived by customer in a very sensitive way.
Investigation and evaluation of importance of main technological aspects were made in order to find
optimal process set up ensuring high mouth rim efficiency. Process data, light microscopy and glass
rim resistance against mechanical load were applied as methods allowing analysis of rim impact
strength. Planned experiments were proposed to quantify the effect of parameters like glass wall
thickness, set up of cracking off, edge melting and toughening process. Influence of glass fining
process causing reboil visible only by light microscopy was found as one of the most important
issues. Optimal process setup was proposed in both directions (i) technological set up and (ii)
statistical process control.
Boundary Layers Refractory/Glass Melt and Glass Defects
Authors: Dunkl Michael
Published: March 2009

In this paper the formation of boundary layers and their behaviour regarding corrosion and glass
defect potential of different refractory/glass melt combinations will be discussed.
The reaction between refractories and glass melts is determined by the diffusion of the different
ions from the glass melt into the refractory material and vice versa. The connected solution
reactions lead to the formation of a saturation boundary layer, which influences the corrosion
behaviour and the glass defect potential.
The behaviour of the boundary layers of various refractory/glass melt types are partly complete
different. On the one side there are refractory/glass melt combinations which form a relative thick
reaction layer, on the other side there are refractory/glass melt combinations with very thin
boundary layers. Thick reaction layers affect in the most cases like a protection layer with a good
corrosion resistance, but there can be a relative high glass defect potential at operation changes.
Thin reaction layers have for the most cases a low glass defect potential, but partly a higher
corrosion rate.
Environmental Impact for Regenerators Materials Selection in Soda-Lime Flat Glass Furnaces
Authors: Meynckens Jean Pierre , Cherdon Benoît
Published: March 2009

The function of regenerators is to use the thermal energy of the waste gases to preheat
the combustion air and thereby provide better heat transfer via a high flame temperature.
Satisfactory furnace operation can only be achieved if the regenerator chambers are in good
condition.
Today, environmental issues play a major role in the selection of regenerators and checkers
refractories. The impact on the environment has been studied on 35 side-fired flat glass furnaces.
Firstly, we will describe in this paper the issues raised by increased carry over and CO content
observed in various furnaces with different types of checker packing such as basket weaves, box
blocks and cruciforms .
Secondly, we will talk about how the impact on health and waste/recycling solutions is analyzed
and should be taken into consideration before ordering refractories.
Finally, some new materials are now appearing on the market. The fact that China dominates
magnesia production (51% of the world production) entails the rise of new raw material sources for
the basic refractories used for checker bricks. Besides that, the refractories suppliers are
continuously improving their materials to offer glassmakers new solutions to overcome the actual
issues in the regenerators. These new sources of materials have been analyzed in R&D and are now
considered as potential solutions which need further testing under industrial conditions.
Nuclear Waste Glasses: Continuous Melting and Bulk Vitrification
Authors: Hrma Pavel , Kruger Albert A.
Published: March 2009

This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes
have a variety of components and composition ranges. For each waste composition, the glass must
be formulated to possess acceptable processing and product behavior defined in terms of physical
and chemical properties that guarantee that the glass can be easily made and resist environmental
degradation. Glass formulation is facilitated by developing property-composition models, and the
strategy of model development and application is reviewed. However, the large variability of waste
compositions presents numerous additional challenges: insoluble solids and molten salts may
segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate
in container refractory walls; on cooling, the glass may precipitate crystalline phases. These
problems need targeted exploratory research. Examples of specific problems and their possible
solutions are discussed.
Structural Changes in Alkali Depleted Alkali-Silicate Glass – MD Study
Authors: Gedeon Ondrej , Charvátová Soňa , Macháček Jan
Published: March 2009

Alkali-silicate glass irradiated with electrons of the medium energy becomes to be fully
depleted of alkali ions after some time. The chemical changes are expected to be accompanied with
significant changes of glass structure. The changes in structure of 15K2O•85SiO2 glass were
simulated by ab-initio MD. Experimental conditions were imitated by the following procedure.
First, glass was prepared by the numerical cooling from the high-temperature melt. Second, alkali
ions were removed. Third, silica structure was relaxed at temperatures 300 K and 1000 K. Structural
changes are characterized in terms PP RDF’s and coordination numbers. It was found peroxide
bonds were created from the dangling bonds, coming from non-bridging oxygen.
Study on the Recycling of Borate Silicate Vitreous Waste with Capitalization of Heavy Metals Sludge
Authors: Diaconu Adriana , Sava Bogdan Alexandru , Ursu Luminita Daniela , Mitiu Ileana , Rosu Elisabeta , Radu Dorel , Dumitrescu Ovidiu , Eftimie Mihai
Published: March 2009

The paper follows both the national preservation and durable managing policy, as well as
the European laws for the area of environmental protection (UE’s Directive 1999/31/EC – „landfill
of waste” an the Council’s Directive no. 94/62/CE regarding the packaging and the packaging
waste, amended by the Council’s Directive no. 2004/12/CE). The proposed technologies lead to
reducing the need of both raw materials and energy in the process of obtaining various types of
glass. The study proposes new ways of retrieving and eliminating waste that contains heavy metals
alongside borosilicate shards. This paper also aims to increase the responsibility of the waste
generating companies and to make the potential users more sensible.
Utilization of Cement Furnace Dust to Produce Colored Vials & its Using in Epoxy Glass Floor
Authors: Zinhom Mohamed Aly Hassan , Youssif Ibrahim Mohamed , Gawad Nihal Abdel
Published: March 2009

The dust of cement furnace is the actual secondary result of cement industry. That, there’s
more than three million tons annually aggregated in Egypt, as it representing great danger whether
to man and the surrounded environment. This because such dust has harmful effect on environment
and beings, especially the close areas from cement factories.
That, using of any cement dust quantity considers good solution of environment pollution, which
resulted from the recent industry, especially cement.
In this research, it uses cement dust to glass mixtures with increased rates may reach 70% of glass
composition mixture’s weight, where such rate doesn’t affect the chemical or physical properties of
obtained glass, so it shall be suitable to be used in many applicable purpose in this industry.
The Effect of CaO and MgO on Physical Properties of MgO-CaO-B2O3-Al2O3-SiO2 Glasses with Composition Close to the E-Glass Fibers
Authors: Kraxner J. , Klement R. , Chromčíková Mária , Liška Marek
Published: March 2009

High temperature viscosity and density of glass melts, glass transition temperature, and
thermal expansion coefficient of glasses from the system MgO-CaO-B2O3-Al2O3-SiO2 with
composition close to the E-glass were measured and interpreted with respect to the effect of CaO
and MgO content on their physical properties. The Andrade model was applied for description of
the temperature dependence of the glass viscosity within studied temperature range. The regression
formaulae describing the compositional dependence of the viscosity points T2 = T( η = 100 dPa.s),
T3 = T( η = 1000 dPa.s), the glass transition temperature, Tg, thermal expansion coefficient of glass,
αg
, and of the viscous flow activation energy, Ea, were proposed.
Volumetric Changes Between Different Conformations of Two SiOH Groups in SiO2 Glass
Authors: Mlejnek M. , Kuchinsky S.
Published: March 2009

We present numerical studies of possible modifications of SiOH groups in “wet” SiO2
glass with 193 nm laser irradiation. We focus on structural changes associated with two
conformations: (i) two nearby hydrogen bonded SiOH groups, and (ii) oxygen triclusters, i.e.
bridging oxygen forming a third covalent bond with a hydrogen atom. The energies of these two
systems and the activation barrier of thermal relaxation between them identify the latter
conformation as a candidate for a product formed under 193 nm laser exposure, when we consider
the former conformation as an initial state. We investigate the effects of local volume changes
associated with the changes in conformation and find it has non-negligible effect on the index of
refraction. These conformational changes thus appear able to contribute to the permanent changes in
index of refraction and absorption of the glass after UV irradiation.
The Yttria-Alumina Glasses - MD and TD Models
Authors: Perichta P. , Liška Marek , Macháček Jan , Gedeon Ondrej
Published: March 2009

The ab-initio molecular dynamics (MD) calculations of the yttrium - aluminate binary
system 23Y2O3·77Al2O3 were performed with help of the Vienna ab-initio simulation package
VASP. The thermodynamic model (TD) of glasses of the studied binary system was constructed.
Both the Y/O and Al/O coordination numbers calculated from the partial pair radial distribution
function (PP RDF) obtained for MD simulated melt at the temperature of 2500 K were significantly
lower than the corresponding coordination numbers obtained from the TD model. The published
neutron diffraction and X-ray diffraction studies give the results close to the results of the present
ab-initio MD simulation. The TD model resulted in higher Al/O and Y/O coordination when
compared with experimental results.
On the Use of Mechanical Weight Functions for Practical Evaluation of Thermal Shock SIF's in Flexibly Restrained Edge-Cracked Plates
Authors: Fillery B.P. , Hu Xiao Zhi , Fisher Gordon
Published: March 2009

Two practical methods have been used to estimate thermal shock stress intensity factors
(TS-SIF`s) associated with a flexibly restrained cracked plate. The first method used a traditional
mechanical weight function (MWF) methodology in conjunction with the MWF derived for an
equivalent freely restrained cracked component. The second method used a traditional MWF
methodology in conjunction with the MWF derived for an equivalent rigidly restrained cracked
component. Fracture mechanic finite element analyses were also undertaken to construct a
comparative benchmark for the TS-SIF`s associated with a flexibly restrained cracked plate. The
results of this comparison demonstrate the errors associated with these MWF methods to be
acceptable, if and only if, the crack size is small, the crack component aspect ratio is large or the
flexible boundary restraint stiffness are deemed negligible or near rigid. In addition, the curves
derived with these MWF methods do not intersect and there is no obvious transition to distinguish
which MWF method would be more appropriate for a given a particular flexible boundary restraint
configuration. In effect, this means that these MWF methods cannot be confidently used to evaluate
the TS-SIF`s associated with a flexibly restrained cracked component.
Asymptotic Analysis of Size Dependent Fracture Strength Using Boundary Effect Concept
Authors: Duan Kai , Hu Xiao Zhi
Published: March 2009

In this paper, the extensively-reported “size effect” phenomena in fracture mechanics tests
are explained using the boundary effect concept. It is pointed out that the widely-observed size effect
in fracture, including the dependence of the fracture energy on ligament, strength and fracture
toughness on crack and/or ligament and the strength of geometrically similar specimens on
characteristic size, is in fact, due to the boundary influence on the crack tip damage zone.
Furthermore, the recently-developed asymptotic model is used to demonstrate that the dependence of
strength on crack and ligament lengths as well as on the characteristic size of geometrically similar
specimens is a result of the dominance of the distance of the crack tip to specimen boundaries on the
specimen failure mode. To verify further the boundary effect concept, the asymptotic model is also
applied to two sets of selected experimental data available in the literature, and the implications are
discussed.
Deterioration Mechanisms in Dragline Wire Ropes
Authors: Dayawansa Daya , Kuruppu Mahinda , Mashiri Fidelis
Published: March 2009

Failures in hoist and drag ropes are studied and described based on site inspections on
Marion and BE draglines. Causes of the failures are discussed. Some of the analyses of the wire
rope failures centres on the wire rope accessories through which these ropes travel during machine
operation. The influence of wire quality on wire rope life is also studied. Visual and metallographic
examinations are both used in this study leading to a better understanding of deterioration
mechanisms that lead to failure of hoist and drag ropes under service loading.
The Effects of Cyclic Loading on Fracture Modes in Brittle Layer Structures: Relevance to Failure of Dental Crowns
Authors: Lam Sarah , Halliday Kimble , Qasim Tarek
Published: March 2009

The effects of cyclic loading on contact damage in curved bi-layer systems are
investigated. Dome structures consisting of glass shells, filled with epoxy resin, simulate the
essential structure of monolithic all-ceramic dental crowns on natural tooth dentine. Cyclic loading,
with only a vertical component, was carried out with the Multi-Functional Chewing Simulator
(Willytec. Munich, Germany). The specimens were tested by indentation with hard spheres of
tungsten carbide, with the load applied axially at the apex of the dome. This project reports some
new results on the effect of cyclic loading on curved bi-layer systems. In addition, the effect of
aqueous environments is addressed. In both air and water tests, observations taken throughout the
cyclic loading course indicated that the outer cone cracks inhibited the propagation of radial cracks.
Results confirm that crack initiation occurred more rapidly in wet conditions of testing,
emphasizing the influences of the moist environment of the oral cavity. Furthermore, the
experiments took into account the evolution of inner cone cracks observed in wet cyclic loading
tests. The new results are important since nearly all-dental crowns exhibit some curvature. The
implications of the results on the failure of dental crowns are discussed.
Does Size Matter? - The Effect of Volume on the Compressive Strength of Open Cell Brittle Ceramics
Authors: Heness Greg , Booth Norman , Ben-Nissan Besim
Published: March 2009

This study investigates the effect of specimen volume on the compressive strength of
open cell brittle ceramics. A series of unconfined compression tests were carried out on specimens
ranging in volume. The crushing strength and apparent stiffness were measured and these results are
correlated with the volume of material stressed. It was found that as the volume of material tested
decreased the strength decreased.
Dynamic Effect on Vibration Signatures of Cracks in Railway Prestressed Concrete Sleepers
Authors: Kaewunruen Sakdirat , Remennikov Alex M.
Published: March 2009

In general, cracks in structural members indicate a level of serviceability of the
engineering structures. Usually a hairline crack can be detected by visual inspection, crack gauge,
fibre optical sensor, or laser sensor. Recently, an attempt to develop a non-destructive tool for health
monitoring of prestressed concrete sleepers in railway tracks using the vibration responses has been
established at the University of Wollongong, Australia. However, the fundamental understanding of
the dynamic effect due to the cracks in sleepers is insufficient. This paper investigates the dynamic
effect of the cracks on the vibration signatures of the railway prestressed concrete sleepers. The
modal analysis has been used to evaluate the modal changes in vibration characteristics of the
prestressed concrete sleepers in the frequency band between 0 and 1,600 Hz. The sample cracks
have been initiated by the impulsive forces attributed to the high capacity drop impact testing
machine. Comparison of the modal parameters of the intact and cracked sleepers has been
highlighted in terms of natural frequencies and modal damping. This understanding will lead to
further development of the economical technology to evaluate the structural integrity of railway
track and its components.
Statistical Analysis of the Tensile Strength of Carbon Nanotubes
Authors: Lu Chun Sheng
Published: March 2009

Two available strength data sets of single-walled and multi-walled carbon nanotubes are
analysed, and the effects of sample sizes on their tensile strengths are investigated. A minimum
information criterion is applied to determine the optimal strength distribution. The results show that,
in contrast to a two-parameter Weibull distribution, lognormal distribution seems to be a more
suitable choice. A simple extrapolation of classical Weibull statistics to nanoscales may result in
overestimation on the tensile strength of carbon nanotubes.
Study on Interlaminar Shear and Damage Behavior of Carbon Fiber Composites with Short Fiber Interleaves: 1. The Comparative Test
Authors: Zhao Li Jun , Zhang Feng Peng , Hu Xiao Zhi , Huang Bao Zong
Published: March 2009

A special test setup was designed and used in compression shear test of unidirectional
carbon fiber composites to study the effect of short fiber interleaves (SFIs) on the interlaminar shear
behavior. The comparative tests for two kinds of double-notched compression specimens, with and
without SFIs, were carried out to determine the interlaminar shear strength and modulus (ILSS and
ILSM) and to examine the failure characteristics. To determine ILSM of the specimens with SFIs an
inversion analysis method was proposed based on comparing compression displacement of
specimens with and without SFIs. The experimental results show that SFIs makes ILSS decreasing
due to lower interface strength, and the complex damage process of SFIs leads to a considerable
increase of interlaminar shear compliance.
Flexural Failure of Unidirectional Hybrid Fibre-Reinforced Polymer (FRP) Composites Containing Different Grades of Glass Fibre
Authors: Sudarisman Sudarisman , Davies Ian J.
Published: March 2009

The flexural behaviour of 6-ply unidirectional hybrid fibre-reinforced polymer (FRP)
matrix composites containing a mixture of E-glass and S2-glass fibres was investigated. A high
performance epoxy system comprising of Kinetix® R240 epoxy resin (combined with Kinetix®
H160 epoxy hardener) was utilised for the composite matrix. Flexural testing was conducted in
accordance with Procedure A of the ASTM D790-03 test standard on a universal testing machine
equipped with a three-point bend test rig. In addition to varying the stacking configurations of the
composite prepregs, the influence of span-to-depth ratio on the flexural properties and failure
mechanisms was also studied. The failure mechanisms of the resulting fractured specimens were
characterised using optical microscopy and compared with those noted by the authors in previous
work.
Dynamic Failure Analysis of Aluminum Foam Sandwich Structure Using 3D Material Point Method
Authors: Wang Can , Chen Hao Ran , Hu Xiao Zhi , Wang Yu Xin
Published: March 2009

The blast-resistant of an aluminum foam sandwich structure under impact has been
investigated. Plastic deformation and load distributions in each of the sub-layers during and after
impact were calculated by the material point method with the consideration of strain rate effect on
deformation of the aluminum foam. The numerical results from the 3D material point method
modeling show that the blast-resistant capability of the aluminum foam sandwich structure is
excellent, and the energy absorbability of the structure would be underestimated if the strain rate
effect on the aluminum foam is ignored.
Life-Limiting Aspects of the Corrosion of Metallic Bipolar Plates for PEM Fuel Cells
Authors: Wang Yan , Northwood Derek O.
Published: March 2009

In proton exchange membrane fuel cells (PEMFCs), the bipolar plates supply the reactant
gases through the flow channels to the electrodes and serve the purpose of electrochemically
connecting one cell to another in the electrochemical cell stack. Requirements of the bipolar plate
material are: high values of electronic conductivity; high values of thermal conductivity; high
mechanical strength; impermeability to reactant gases; resistance to corrosion; and low cost of
automated production. Metallic materials meet many of these requirements but the challenge has
been in obtaining the required corrosion resistance. In the paper, six metallic materials were
investigated as potential bipolar plate materials. The results showed that the corrosion rates were
too high even for the most corrosion resistant metals (SS316L and grade 2 Ti), and that coatings
would be required.
Investigation and Improvement of Corrosion Resistance in Automotive Fuel Tank
Authors: Abbasi Erfan , Salmani Mohammadreza
Published: March 2009

In the result of corrosion phenomena in automotive metallic fuel tank, a layer of rust which consists
of hard and micronized oxide grits with low cohesion and adhesion could appear. Through gasoline
delivery from fuel tank to chamber of combustion, these hard and micronized grits could cause
erosion and service problem for the components in this rout.
In concept of after sale services, some defective parts such as fuel tank, injector pump,
nozzle of injector and etc, needs to be repaired or changed due to the corrosion.
In this article in order to improvement of corrosion resistance, some investigations into the
recognition and assessment of corrosion in which relative these parts have been done. The corrosion
mechanisms such as galvanic corrosion, general corrosion have been recognized. Based on this
information modification and improvement are concentrated in field of welding, plating showed
considerable improvement in corrosion resistance.
Study of Dynamic Properties on NMMCs Material Using Ansys/LS-DYNA
Authors: Liang Li , Li Ming , Tsai Chi Tay
Published: March 2009

Dynamic properties of Nanostructured Metal Matrix Composites (NMMCs) materials
consisting of nanograined aluminum matrix with nano or micro-sized ceramics particulates are
calculated using Ansys/LS-DYNA in this paper. There are three conditions for the mechanics
analysis involved the target with 10 vol. % SiC, 30 vol. % SiC and 50 vol. % SiC. It is assumed that
the SiC particles uniformly distributed in the matrix. According to the analysis, the strength of
NMMCs material is reduced, and the deformation of target is weakened by the vol. % of SiC
increasing.
Manufacture of 3D Curved Profiles for Structure Components
Authors: Becker Dirk , Schikorra Marco , Tekkaya A. Erman
Published: March 2009

Curved Profile Extrusion (CPE) is an extension of the common extrusion process and
offers the possibility to manufacture three-dimensionally curved profiles. Due to the flexibility of
the process different curvatures can be produced with the same setup, which makes this technique
efficient especially for low volume production. The process is characterized by a controlled lateral
deflection of the strand which influences the material flow in the die and causes the profile
curvature. In this paper, a direct comparison of the power rating between warm bending and CPE is
presented. Furthermore, the investigations concerning the choice of support strategy of the
surmounting profile by a robot to increase the curvature accuracy are continued. Finally, some
extensions of the equipment are explained to increase the level of process integration.
A Modelling Approach for the Manufacturing Process Chain of Composite Lightweight Structures
Authors: Zaeh Michael F. , Langhorst Mirko
Published: March 2009

In order to support production tasks in the automotive industry, to reduce costs due to a
trial and error procedure during process design and plant construction and to secure the accuracy of
frame component assemblies, modern simulation methods are applied. In production chains a row
of different manufacturing techniques are established. To accompany the number of manufacturing
steps with the aid of calculation methods, an interacting of each simulation with the preliminary one
is necessary. Such process chains help to determine the structural properties and geometrical accuracy
of components and assemblies during manufacturing of composite lightweight structures and
ensure their final quality. The basic difficulty of handling aluminium composites with steel reinforcements
is the high residual stress level in the reinforcing elements and the adjoining matrix.
This stress state can have a significant effect on the desired machining results and the related process
itself. Contemplating this reveals the importance of defining a process chain by simulation.
Prototype Manufacturing of Extruded Aluminum Aircraft Stringer Profiles with Continuous Reinforcement
Authors: Kloppenborg Thomas , Hammers Thilo , Schikorra Marco , Kerscher Eberhard , Tekkaya A. Erman , Löhe Detlef
Published: March 2009

For an increase in safety against crack initiation and growth in metallic structures of
airplanes different concepts were developed in the past. In the focus of this work are profiles made
of continuously reinforced extruded aluminum. The production and the used die set of these profiles
is presented as well as problems occurring in terms of geometrical inaccuracies of the embedded
high strength wires. In addition, this paper attends to the problem of lateral seam weld formation.
The interface between the AA-2099 as well as AA-6056 aluminum alloy and the high strength wires
Nivaflex and Nanoflex were characterized by metallurgic investigations and push-out tests. As a
result it can be stated that a sufficient geometrical accuracy could be achieved and a high interface
strength can be accomplished even if a slight gap is still present in the interface layer between
matrix and reinforcing element.
Influence of Process Parameters on Structure and Mechanical Properties of Joints Produced by Electromagnetic Forming and Friction Stir Welding
Authors: Barreiro Pablo , Schulze Volker , Löhe Detlef
Published: March 2009

Electromagnetic compression of tubular profiles with high electrical conductivity is an
innovative joining process for lightweight structures. The components are joint using pulsed
magnetic fields which apply radial pressures of up to 200 MPa to tubular work pieces causing a
symmetric reduction of the diameter with typical strain rates of about 104 sec-1. Since there is no
contact between the components to be joined and the joining machine, any damage of component’s
surface can be avoided. Friction stir welding (FSW) is a relatively new solid state joining technique
and has been extensively developed for aluminum, magnesium, copper and titanium alloys as well
as steels. The primal advantages of the process in comparison to conventional fusion welding are
better mechanical properties, low residual stresses and distortion, and reduced occurrence of defects.
In the present article, the influence of process and material parameters on the joint’s characteristics,
material’s microstructure and the mechanical properties of electromagnetic compressed joints and
friction stir welds using reinforced aluminum profiles is analyzed. The strength of the joint is
determined by tensile tests. Finally, possible improvements of both techniques are outlined.
Investigation into Leakage Behavior of Bolted Flanged Connection with Octagonal Gasket
Authors: Zhou Han Qiu , Gu Bo Qin
Published: March 2009

Structural strength and leakage failures are two types of main failures of the bolted flanged
connection with octagonal gasket, and they are related to the gasket contact stress and gasket effective
contact width to a great extent. The deformation behavior of connection subjected to various bolt
loads and medium pressures is studied by numerical simulation. The distribution of the gasket actual
contact stress, the change of the gasket average contact stress and gasket effective contact width are
discussed. The relationship among the gasket average contact stress, the gasket effective contact
width, bolt load and medium pressure are obtained. A model for predicting the leakage rate of the
sealing connection with octagonal gasket is developed. Research indicates that the gasket actual
contact stress distributes non-uniformly, and at gasket outer flank it is much larger than that at gasket
inner flank. Both the gasket average contact stress and the gasket effective contact width increase with
increasing bolt load and medium pressure. The leakage rate is largely related to working conditions,
gasket contact stress, gasket effective contact area, and so on. The leakage rate decreases with
increasing gasket effective contact area and gasket average contact stress, and it increases linearly
with increasing medium pressure. The leakage through the octagonal gasket connection shows the
characteristic of the laminar flow of incompressible viscous fluid.
Finite Element Analysis on Fatigue Stress History of a Railway Bogie Bolster
Authors: Peng Jia Chung , Zhao Yong Xiang , Yu L.Y. , Yang A.G.
Published: March 2009

An efficient finite element (FE) method, multivariate quadratic regression approach, is
proposed for calculating the fatigue stress spectrum of engineering structures. The calculation starts
from a dynamic load history. A regression function is established as a relation from the concurrent
components of structural balance force systems into the structural stress. Parameters of the relation
are measured by the stress data using an elastic-plastic FE method under selected groups of balance
force systems. The selected systems should cover the possible load range with a similar service
condition. After passing the fit effect check, the regression equation can transfer the structural load
history into the stress history at the preferred position. Application on the determination of fatigue
stress spectrum for the bolster of K6 type bogie has indicated availability of the present approach.
Some deficiencies have been overcome from the much time cost by transient approach and the entire
elastic material relation by quasi-static approach.
A Novel Methodology to Manage Uncertainty for Multidisciplinary Design and Optimization in Conceptual Design
Authors: Shao Xin Yu , Chu Xue Zheng , Gao Liang , Qiu Hao Bo
Published: March 2009

Uncertainty in design and simulation affects the quality of product directly during the
process of MDO, which should be considered to help designers to make the design decisions,
especially at conceptual design stage. In traditional approaches, this uncertainty is ignored in the hope
that it is not significant to the decision making. In this investigation, firstly, three main uncertainties in
MDO of conceptual design are pointed out and carefully analyzed. Then, an innovative methodology
integrating extract knowledge and probabilistic method to manage these uncertainties is presented.
Considering practical application and eliminating the uncertainty in configuration, we propose a
promising method combining Fuzzy c-means algorithm (FCM) and Rough Sets theory (RST) to
deduce the configuration rule. Furthermore, probabilistic kriging model is utilized as an
approximation model to reduce global computational expense of complex product. Sensitivity
analysis (SA) is used to reduce uncertainty of inputs of simulation, and mean square error (MSE) is
employed to assess model error to reduce model uncertainty. Finally, the validity and necessity of this
methodology are demonstrated through the conceptual design of bulk carrier.
Research on Workflow Modeling Methods for Collaborative Product Development
Authors: Qiu Hao Bo , Wang Y. , Jiang Ping , Gao Liang
Published: March 2009

Collaborative Product Development (CPD) is an advanced paradigm for product
development, which focuses on facilitating the business collaboration across organizational
boundaries. The process of CPD is highly dynamic, and needs to be implemented jointly by
participant organizations. Firstly, this paper analyzes some traditional workflow modeling methods,
and reviews related research work on workflow modeling for CPD. Secondly, a process-view and
Petri nets combined approach is highlighted. At last, a novel process management framework is
proposed, which provides an effective and universal way to manage the dynamic and distributed
process of CPD.
The Parameter Selection System of Vehicle Overall Design Based on Cooperation and Specialty
Authors: Zhang L. , Shao Xin Yu , Gao Liang , Tao Wu
Published: March 2009

The process of parameter choosing in vehicle overall design is a process of collaboration
design, and is also a process of group decision optimization. The degree of cooperation and level of
experts become the crucial standards in Computer Supported Collaborative Design because many
decision-makers participating in the design process have different expertise and goals. This paper
describes vehicle overall design parameter selection with a Multi-Objective Decision-Making
optimization model, presents the concepts of non-cooperation degree and non-specialty degree, and
uses entropy to describe the model. Furthermore, Particle Swarm Optimization (PSO) algorithm is
employed to resolve the model and to get optimal parameter. In addition, we propose an effective
expert system based on the model and actual design process. Finally, the effect of the non-cooperation
degree and non-specialty degree on the result is discussed and the sensitivity of the proposed system
analyzed in this paper.