bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined Inhibitory Effect of Curcuma Xanthorrhiza Extract and Xylitol on Streptococcus Mutans and Actinomyces Viscosus
Authors: Kim Hae Sun , Choi Choong Ho , Kwon H.K. , Kim B.I.
Published: March 2009

This study evaluated the combined inhibitory effects of a Curcuma xanthorrhiza extract (CXE) and
Xylitol on S. mutans and A. viscosus in vitro. Three series of experiments on S. mutans and A.
viscosus were carried out. In the first series, the Minimum inhibitory concentrations (MICs) of
CXE, Xylitol, and CXE mixed with Xylitol (CXE+Xylitol) against S. mutans and A. viscosus were
determined. Second, the antibacterial effect and the rapid effectiveness of CXE, Xylitol, and
CXE+Xylitol against those bacteria was evaluated as contacting for 1, 2, 5, and 10 minutes. Finally,
The saccharolytic capability of S. mutans was examined using bovine teeth that had been pretreated
with CXE (1%), Xylitol (1%), CXE+Xylitol (1%), chlorhexidine (1%) and distilled water, and
rinsed with distilled water. The pretreated bovine teeth were layered with soft agar containing
sucrose (5%), S. mutans and phenol red, as a pH indicator, and incubated. The MICs of CXE were 5
ppm on both bacterial species. Xylitol did not inhibit either species. The MICs of CXE+Xylitol
were 10 and 5 ppm against S. mutans, A. viscosus, respectively. According to the rapid
effectiveness, CXE completely inhibited the growth of bacteria but Xylitol did not. CXE+Xylitol
could completely inhibit the growth of bacteria. An evaluation of the saccharolytic capability of S.
mutans on bovine teeth revealed that distilled water and Xylitol could not inhibit bacterial
fermentation. However, the bovine teeth containing CXE, CXE+Xylitol and chlorhexidine inhibited
the fermentation of bacteria. These results show that CXE and CXE+Xylitol have a strong
antibacterial effect on S. mutans and A. viscosus in vitro.
A Three-Dimensional Finite Element Analysis with Various Implant Designs
Authors: Yoo Dong Ki , Heo Seong Joo , Koak Jai Young , Kim Seong Kyun , Lim Young Jun , Kim Sung Hun , Han Chong Hyun
Published: March 2009

Various studies recommend that threaded type implants should be used to maximize
initial contact, improve initial stability, enlarge implant surface area, and favor dissipation of
interfacial stress. The objective of this study was to compare four types of screw implants placed in
posterior region of mandible model and evaluate the influences of implant shape, configuration,
length, diameter and abutment connection method on stress distribution using a three-dimensional
finite analysis. Four types of two-length implant models — 8.5 and 13 mm — were selected and the
wide diameter was also used. Four groups were classified by implant outline and connection
manner A load of 100 N was applied vertically on the center of the implant. Oblique and horizontal
loads were taken as equal to that of the vertical load. The TMJ area in mandibular model was
constrained in all directions. Results show that the stress of two-length implants was similar in all
groups and the internal connection implant with appropriate thickness of inner part of the implant
had better stress distribution.
Prediction of Intraosseous Pressure Behavior to Understand Strain Generated Potential near Osseointegrated Bone and Implant Composite
Authors: Min Sung Ki , Hong Jung Hwa , Ko Sang Ok
Published: March 2009

Osseointegration (OI) could be described as the modality for stable fixation of titanium
implant to bone structure. The OI has become a realized phenomenon of importance in the dental
and rehabilitation sciences since recently developed dentures and artificial limbs are directly
attached to human skeleton by using osseointegrated implants. Previously, a study showed that bone
strain generated potential (SGP) that is an electrical potential and considered to be generated by
fluid flow in bone could be used as a parameter to examine the amount of OI on implant-bone
interface. SGP generation is known to require intraosseous fluid flow related with generations of
pore pressure gradient in bone. Therefore, SGP would interact with properties determining
interstitial fluid flow characteristics such as viscosity, velocity, flow path directions, and interstitial
fluid flow boundary conditions. Since interstitial fluid flow characteristics in bone are governed by
pore pressure gradient, it could be possible to predict SGP indirectly through the prediction of pore
pressure generation in bone. The aim of this study is to predict the distribution of pore pressure in
OI bone-implant composite representing a completely osseointegrated rabbit tibia-titanium implant
composite. The theoretical background of this prediction is based on the poroelasticity of 2-phase
material that grounds on fluid flow and behavior of cortical bone material. In this study, we
constructed a finite element (FE) model of the composite from images of micro-CT scanning. In the
next step, we examined analysis of the FE model about pore pressure by using ABAQUS. In this
analysis, the constitutive behavior was externally computed by utilizing a user subroutine. The
results showed the different spatial distributions of pore pressure in the composite. The magnitudes
of pore pressure were found to be significantly increased when the position was approached for the
interface of implant-bone. Further analytical study is required to fully understand relationships
between SGP and pore pressure distributions in OI bone-implant composite materials.
Effect of Stabilization of Changing Viscosity in Chitosan Solution as a Bio-Adsorbent
Authors: Na Jae Sik , Park Sang Soon , Kim Chun Ho , Lee Sang Bong , Jung Byung Ok
Published: March 2009

The emulsion stabilizing potential of chitosans was compared in the presence of organic
additives. The 4 types suspension of 0.1 wt% of chitosan flocculant were obtained by mixing of
chitosan colloidal dispersion with three kinds of additives; sorbic acid, benzoic acid and
dibutylhydroxytoluene (BHT). The viscosity of emulsion revealed the following order of stabilizing
potentials; sorbic acid > benzoic acid > BHT. As a bio-adsorbent for the treatment of biomedical
wastewater, the results were capable of adsorbing more than 30% of pure chitosan. The chitosan
emulsions represented that the removal efficiency were increased by COD 59.2%, BOD 70.1%, Zn
77.1%, Cu 93.7%, E. coli 99.4%. As a result of this investigation, it is remarked that the high
stabilizing potential of chitosan solution is explained by higher adsorption efficiency with organics,
heavy metals and microorganism, and that the effectiveness of chitosan solution for coagulating
biomedical wastewater suspension could be improved due to stabilization of the viscosity in the
presence of organic additives.
Deburring of Sheet Metal by Barrel Finishing
Authors: Boschetto Alberto , Ruggiero Armando , Veniali Francesco
Published: March 2009

In sheet metal processes the burrs cannot be completely eliminated during the process but
can be minimized by optimization of the process parameters. Hence the deburring often becomes an
essential secondary operation. Most of the deburring operations are hand-made and therefore
several manufacturers tend to eliminate these tedious and labor-intensive operations due to time and
cost issues. Moreover, clamping problems can arise which, together with the deburring forces, can
induce dimension alterations and local deformations, particularly for thin sheets. Barrel finishing is
an old technique commonly used to improve the surface roughness of complicated parts, but can
find interesting applications also in the deburring. Aim of this work is to present an experimental
investigation on the deburring of sheet metal performed by barreling. A technological model has
been developed in order to assess the height of the burr as a function of the initial burr and of the
working time.
Application of Tailored Heat Treated Blanks under Quasi Series Conditions
Authors: Merklein Marion , Vogt Uwe
Published: March 2009

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength
specifically optimized for the succeeding forming process. The strength distribution is set by a local,
short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow
enhancing forming limits significantly leading to shorter and more robust manufacture process
chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of
the blank’s local heat treatment and the entire process chain of the car body manufacture have to be
analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of
AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the
influence of a short-term heat treatment on the coil lubricant, usually already applied by the material
supplier, was given a closer look. Based on these experiments process restrictions for the
application of THTB in an industrial automotive environment were derived and a process window
for the THTB design was set up. In conclusion, strategies were defined how to enhance the found
process boundaries leading to a more robust process window.
FEM Modeling of Self-Piercing Riveted Joint
Authors: Atzeni Eleonora , Ippolito Rosolino , Settineri Luca
Published: March 2009

The present paper aims at defining a numerical tool for the efficient design of the selfpiercing
riveting process by means of FE simulations. Abaqus Explicit v.6.4 software has been used
to establish a model for 3D simulation of the joining process and of the shearing test on the riveted
joint, in order to understand the joint formation and failure mechanisms. The obtained indications
have been validated experimentally through joint sectioning and comparison between real geometry
and numerical results. Furthermore, shear tests have been performed to compare the experimental
and numerical results in terms of joint resistance.
Temperature Dependence of Deformation Behavior in Magnesium and Magnesium Alloy Single Crystals
Authors: Ando Shinji , Harada Naoharu , Tsushida Masayuki , Kitahara Hiromoto , Tonda Hideki
Published: March 2009

It is important to research activation of the slip systems in magnesium crystals to
understand deformation behavior of magnesium. In this study, pure magnesium, Mg-7.0at%Li and
Mg-0.1at%Zn single crystals were stretched in the [11-20] direction in the range of 77K to 573K to
investigate the deformation behavior by non-basal slip. The active slip system was investigated by
the observation of slip bands, etch pit bands and dislocations by TEM. {11-22} <-1-123> second
order pyramidal slip is activated in all magnesium and magnesium alloy single crystals, and its yield
stress shows anomalous temperature dependence in the range from 77K to 293K, however, the
yields stress decreased rapidly with increasing temperature above 293K. The yield stress due to
the pyramidal slip in Mg-Li and Mg-Zn alloy were lower than that of pure magnesium about 20MPa
whereas the stress of Mg-Zn at 77K was about two times higher than pure magnesium.
Effect of Refractory Ceramic Coating on the Thermal Oxidation Resistance of Inconel 617 Alloy
Authors: Cho Hyun , Lee D.M. , Bang K.H. , Lee B.W.
Published: March 2009

Effect of ceramic coating (TiN, TiCN, TiAlN or Al2O3) on the wear resistance and
thermal oxidation behavior of Inconel 617 alloy (Ni-22Cr-12.5Co-9Mo-1Al) have been examined.
TiAlN and Al2O3 coatings showed lower wear loss than bare Inconel 617 and the enhanced thermal
oxidation resistance at 1000oC by suppressing the inhomogeneous formation of Cr2O3 at the surface
region through the reaction between oxygen and grain boundary-diffused Cr, one of the main
component of Inconel 617 alloy, while TiN and TiCN coatings showed poor temperature stability at
the temperature region above 600 oC.
A General Model to Chemo-Mechanical Equilibrium of a Geo-Synthetic Polymeric Membrane
Authors: Buonsanti Michele
Published: March 2009

The interaction between two or more independent causes of materials degradation results
in a duplex mode of materials degradation. The materials degradation rate whether expressed in
loss of material or loss of mechanical strength is often faster than the sum of each form of materials
degradation acting separately. For this reason, duplex modes of materials degradation are of great
practical importance. Synergisms between unrelated forms of materials degradation are not
immediately obvious and have in some instances been only recently recognized. In this paper a
chemically aggressive environment over a geo-synthetic polymeric membrane is investigated. The
membrane free energy depends upon the mono-axial strain and the degree of reaction with an
external agent. We suppose chemical potential assigned and the minimization problem is
formulated. Practically the minimum problem is non-convex, and coexistence of equilibrium phases
is possible. The proposed general model is able to describe the complex phenomenon when
polymeric geo-synthetic membrane are undergoing to heterogeneous and complex action of the
package system built in dump of urban waste. Finally a FEM simulation is compared with
minimization problem theoretical results.
Environmental Fatigue Behaviors of SA508 Gr.1a Low Alloy Steel in 310°C Deoxygenated Water
Authors: Cho Hyun Chul , Jang Hun , Kim Byoung Koo , Kim In Sup , Jang Chang Heui
Published: March 2009

The low cycle fatigue tests of SA508 Gr.1a low alloy steel were carried out to investigate
the fatigue crack growth mechanisms in high temperature water. The fatigue life in 310oC
deoxygenated water was shorter than that in air. Furthermore, the reduction in the fatigue life in 310oC
deoxygenated water was enhanced with a decreasing strain rate, from 0.4 to 0.008 %/s. The ductile
striations with the streamed down features, which may indicate the occurrence of the metal
dissolution, were mainly observed at the strain rate of 0.008 %/s. And the flat facets and the brittle
cracks, which may be evidences for the HIC, were primarily observed in the strain rate range from
0.04 to 0.4 %/s. From the analysis of microstructure, it is thought that the HIC contribute dominantly
to the reduction in the fatigue life in the strain rate range from 0.04 to 0.4 %/s and the metal
dissolution is mainly responsible for the reduction in the fatigue life at the strain rate of 0.008 %/s.
Fatigue Characteristics of Low Carbon Steel in Hydrogen Gas Environment
Authors: Noguchi Hiroshi , Oda Yasuji
Published: March 2009

In order to investigate the effect of hydrogen environment on fatigue crack growth
characteristics of a low carbon steel JIS S10C, fatigue crack growth tests were conducted in a low
pressure hydrogen gas environment. Fatigue crack growth rate in hygrogen gas is higher than that in
nitrogen gas. It seems that a crack in the range of low growth rate prefers to propagate along the
grain boundaries under hydrogen environment while in the range of high growth across the grains
accompanied by brittle striation patterns or river patterns. It is important to clarify how hydrogen
affects the crack growth behavior of different stages of crack growth.
Finite Element Analysis of the Forging Process of Magnesium Wheels
Authors: Xia Zi Hui , Ju Feng
Published: March 2009

The high specific strength of the magnesium alloy makes it a valuable choice for
automotive, aerospace and sporting industries, where the weight reduction is a critical consideration
in design. However, wrought magnesium alloys offer a poor formability at room temperature and a
hot working condition is required for the forming process. This paper studies the application of
finite element methods for the simulation of the forging of magnesium alloys. Numerical analysis of
the forging process of an automotive magnesium wheel is conducted based on the tested flow curve
of AZ80. The effect of friction on the final deformation of the upsetting of magnesium billets is also
discussed.
Diameter Expansion Deformation Behaviors of Midair Shaft under Various Processing Conditions
Authors: Fujiki Kengo , Zhu Xia , Mori Kazuki , Okabe Nagatoshi
Published: March 2009

The basic investigation was conducted for the diameter enlarging machine of a shaft by
repeating cyclic torsion newly developed as a novel idea. With a concept repeating the alternate cyclic stress
on a shaft subjected to axial-compressive force, the plastic working method to cause diameter enlarging
deformation on a part of shaft was proposed. In this investigation, the diameter enlarging experiment and the
model analysis by FEM with notice of the deformation behaviors on diameter enlarging process were
conducted as axial-compressive stress σc and torsion angle θ for mild steel pipes of SGD400. About
300cycles of cyclic torsion was repeated the cyclic torsion angle θ=3°as a standard process condition to a
shaft subjected to axial-compressive stress of σC/σy0 =1.0. In this condition, the shaft has enlarged to about 1.3
times of initial diameter (D/D0=1.3). The experimental value was in excellent agreement with the analysis
value. Also, not only diameter enlarging deformation behaviors but also influence of machining conditions on
the behaviors was clarified.
Micro-Incremental Forming of Ti and Au Foils by Indentation Method
Authors: Otsu Masaaki , Taniguchi Hiroshi , Takashima Kazuki
Published: March 2009

Ti and Au foils with a thickness of 10μm were formed by indenting at a place neighboring
another indented place sequentially by means of a hemispherical diamond tool with a radius of 5μm.
In this forming method, forming dies are not necessary and commercial equipments for
nanoindentation can be used. Forming load and pitch were changed in single line forming and
forming direction, line pitch and line number were changed in plural line forming, and bending angle
was investigated. From the experimental results, bending angle of Ti foil was greater than that of Au
one when same working conditions were employed. As the forming pitch increased, bending angle
decreased. When the forming line pitch was changed, bending angle had the maximum peak at a pitch
of 30μm by one-way forming path and 25μm by two-way forming path. Bending angle by one-way
forming path was larger than that by two-way forming path. As forming line number increased,
although bending angle increased, increment of them became smaller.
Application of Stress Analysis by Digital Image Correlation and Intelligent Hybrid Method to Unidirectional CFRP Laminate
Authors: Machida Kenji , Sato Mitsuru , Ogihara Shinji
Published: March 2009

Fiber reinforced composites are heterogeneous and anisotropic. The applicability of the
stress analysis methods on such heterogeneous and anisotropic materials is not well known. In the
present study, an attempt is made to apply the digital image correlation method and the intelligent
hybrid method to a carbon fiber reinforced plastic (CFRP) laminate. A material used is
carbon/epoxy system. Laminate configuration is unidirectional. Tensile load is applied in off-axis
(45 degrees) direction as well as longitudinal (0 degree) and transverse (90 degrees) directions on a
CFRP laminate. Displacement, strain and stress fields due to the tensile loading in the CFRP
unidirectional laminate are analyzed. The constitutive equation considering material anisotropy is
built into the intelligent hybrid method used at the time of analyses. The validity of the algorithm is
checked through comparison between results of the present method, experimental results from
strain gauge method, and the analytical results from finite element method (FEM).
Characterization of Polymer Adhesion through Modified JKR Theory and Instrumented Indentation Technique
Authors: Lee Gyu Jei , Park Sang Wook , Kang Seung Kyun , Kim Kug Hwan , Han Jae Hwan , Kim Kun Nyun , Kwon Dong Il
Published: March 2009

The Johnson-Kendall-Roberts (JKR) theory was combined with the instrumented
indentation technique to evaluate the work of adhesion and modulus of an elastomeric polymer. An
indentation test was used to obtain the load-displacement data for contacts between a diamond
indenter and poly(dimethylsiloxane), PDMS. The JKR theory, modified to avoid the effect of
ambiguous contact radius and depth for nanocontact, was applied to take into account surface
adhesion and viscoelastic effects of the compliant polymer. Future work will include experimental
verification that polymer stiffness in JKR contact is a time-dependent function.
Mechanical Behaviour of Cellular Solids and Their Sandwich Panels under Impact Loading
Authors: Zhao Han , Nasri I. , Li Hui Jian
Published: March 2009

This paper presents a experimental study of the strength enhancement under impact
loading of metallic cellular materials as well as sandwich panels with cellular core. A testing
method using 60mm diameter Nylon Hopkinson pressure bars is used to investigate the rate
sensitivity of various metallic cellular materials as honeycombs, foams. Finally, an inversed
perforation test on sandwich panels with an instrumented pressure bar is also presented. Such a new
testing setup provides piercing force time history measurement, generally inaccessible. Testing
results show a notable enhancement of piercing forces, even though the skin aluminum plates and
the foam cores are nearly rate insensitive.
Real-Time Observations on Deformation and Failure of LY12 Samples under Impact Tension
Authors: Chen Si Ying , Huang Chen Guang , Lan Tian , Ni Guo Qiang
Published: March 2009

In this paper, the real-time deformations and failures of LY12 samples loaded by an
SHTB are investigated by an optical system, which consists of a high-speed camera, a flash lamp, a
frame grabber and a synchronization device with the controlling accuracy of 1 microsecond. The
deformation history of LY12 is obtained with a time interval of 10μs and the result is compared
with that acquired by classic Hopkinson method at the same time. Besides, two different failure
modes and the crack propagation velocity of LY12 specimen are detected in impact tensile process.
The fracture textures after working are also surveyed by SEM and it shows that the dynamic
fracture mode is affected by the microstructure of materials.
Three-Dimensional Measurement of Local Strain Distribution by Tracking Microstructural Features in High-Resolution SR-CT Image
Authors: Kobayashi Masakazu , Toda Hiroyuki , Ohgaki Tomomi , Uesugi Kentaro , Wilkinson David S. , Kobayashi Toshiro , Aoki Yoshimitsu
Published: March 2009

The local elastic and plastic strain during deformation are very complicated and different
form the macroscopic strain, because most materials have inhomogeneous microstructure. In this
study, local strain distribution in three dimensions has been measured using the new developed
method based on image analysis in high-resolution synchrotron radiation computed tomography
(SR-CT). Model and practical specimens, which made of cupper alloy and aluminum alloy,
respectively, were prepared for a development procedure and application of local strain
measurements. Gauging intervals of microstructural features before and after deformation gave us
information of inhomogeneous local strain distribution in three dimensions. High strain was observed
in a necking region appeared after tensile deformation in the model sample. A combination of
non-destructive measurements by SR-CT and three-dimensional analysis revealed inhomogeneous
strain distributions in practical aluminum samples.
Development of Pore Pressure Measurement System in Lacunocanalicular Network of Trabeculae Using MEMS Based Micro-Pressure Transducer
Authors: Hong Jung Hwa , Park Young Hwan
Published: March 2009

Experimental measurement of pore pressure generation in lacunocanalicular network of
trabeculae is never measured, although the characteristics could be important for bone remodeling.
In this study, the pore pressure generation in micro-trabecular specimens within the elastic range
was measured in vitro using a specially designed micro-experimental setup and a MEMS based
micro-pressure transducer. Then, a quasi-static loading (9㎛/min) was applied up to the strain of
0.4 % with measuring pore pressure generations in the undrained and drained conditions. 49.2 ±
4.45 KPa of pore pressure generation at the 0.4% strain was found in the undrained condition. In
contrast, no pore pressure generation was measured in the drained condition. The result could let us
know the amount of a possible maximum pore pressure generation in lacunocanalicular network of
trabeculae within the elastic range.
Measurement of Adhesion Strength for Patterned Single Layer Ceramic Capacitor Sheet
Authors: Huh Yong Hak , Kim Dong Iel , Kim Dong Jin , Lee Kyung Ho , Kim Dong Jin
Published: March 2009

Adhesion strength for single layer ceramic capacitor sheet, used in MLCC(Multilayer
Ceramic Capacitor), was measured by peel tests. The peel strength was measured during the
separation of the ceramic sheet from the PET film using the peel testing system developed in this
study. The sheet specimen was adhered on the glass jig floating on the liquid media, which was
designed to minimize the friction, and the specimen was pulled up by micro-actuator. In this study, the
dependency of the specimen width, peel angle and testing speed on the adhesive strength was
experimentally investigated. It was found that the adhesive strength for the ceramic sheet is nearly
identical, irrespective of the specimen width ranged from 5 to 20 mm, and the adhesive strength was
increased with increasing testing speed. Furthermore, the strength was shown to be dependent on the
peel angle.
Mechanical Surface Behavior of ZrN and TiN Coated Dental Screw by Ion-Plating Method
Authors: Choe Han Cheol , Chung Chae Heon , Brantley William A.
Published: March 2009

The abutment screw loosening of dental implant system has been remained problem in
restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in
implant screw mechanism. The purpose of this study was to investigate surface characteristics of ZrN
and TiN coated dental gold-screw and Ti-screw by ion-plating method and to evaluate wear resistance,
surface roughness, and film adhesion on the screw surface using field emission scanning electron
microscopy(FE-SEM), energy dispersive x-ray spectroscopy(EDX), micro-diamond scratch tester,
vickers hardness tester, and surface roughness tester. The surface of gold screw and GoldTite is more
smoothly than ones of other kinds of non coated screw. The ZrN and TiN coated surface is more
smoothly than ones of other kinds of screw. The hardness of TiN and ZrN coated
surface showed higher than that of non coated surface. The TiN coated titanium screw and ZrN coated
gold screw have a good wear resistance and adhesion on the surface. The surface of ZrN coated screw
showed low surface roughness compared with the surface of TiN coated screw.
Formability of Beta Titanium Alloy in Multi-Stage Deep Drawing Process
Authors: Harada Yasunori , Fukaura Kenzo , Mori Kenichiro
Published: March 2009

In the multi-stage deep drawing processes of a beta titanium alloy sheet, the formability has
been investigated. The beta titanium alloy sheets have sufficient ductility at room temperature,
whereas a seizure tends to occur during deep drawing due to high reactivity with other materials. To
prevent the seizure, the beta titanium alloy sheet was treated by oxide coating heating, because the
coated sheet was not in direct contact with the die during deep drawing due to the existence of the
oxide layer. The blank used was the commercial beta titanium alloy Ti-15V-3Cr-3Sn-3Al. The effect
of the coating condition on the formability in the multi-stage deep drawing process was examined. It
was found that long drawn cups with a height sixfold that of the diameter were successfully formed by
oxide coating heating.
The Effects of Coatings at Diamonds on the Mechanical Behavior of Metal-Diamond Composites
Authors: Yu Yi Qing , Li Yuan , Xu Xi Peng
Published: March 2009

The present study was undertaken to examine the effects of metal coatings at the surfaces
of diamonds impregnated in metal bond matrices. Diamonds with or without coatings were
incorporated into same bond matrix to form two metal-diamond composites in order to reveal the
effects of coatings. Diamonds with same coatings were applied to three bond matrices to check the
influences of matrix properties on the effects of coatings. The transverse rupture strength (TRS) of
the composites was measured to ssess their mechanical behavior. Circular sawing was also conducted
to reveal the contribution of coatings to diamond retention. SEM was used to analyze the fractured
surfaces of the composites. For same bond matrix, the coatings at diamonds were found to increase
the TRS of the composites. However, it is difficult to compare the effects of coatings in different bond
systems.
Magnetic Investigation of Thermal Shock Fatigue Process
Authors: Mészáros István , Ginsztler János
Published: March 2009

In the present paper we summarize some of our results obtained in the field of magnetic
testing of thermal shock fatigue testing of power plant steels. In this work 15Mo3 type ferritic heat
resistant steel was investigated. This steel and several similar grades are commonly used in power
plants boilers as the material of reheating steam pipelines and pressure vessels. Their typical
application temperature is about 500-550 °C. It is commonly accepted that a combined form of
mechanical, thermal fatigue and the creep processes causes the long term deterioration of this
structural steels. The applied thermal shock fatigue test can model the material degradation due to
long term service in high temperature environment. A parallel motion vibrating sample
magnetometer, an AC permeameter and a magnetic Barkhausen noise measuring device was used
for testing the magnetic properties of the samples and several different magnetic properties were
measured to characterize the microstructural processes of the deterioration.
Influence of the Thickness and Frequency in the Infrared Hybrid Method in Consideration of Heat Conduction
Authors: Machida Kenji , Hayafune Koichi , Miyagawa Shohei
Published: March 2009

The thickness dependency of the temperature image obtained by an infrared
thermography was investigated using specimens with three kinds of metal materials of different
heat conduction and four kinds of thickness of the specimens. Then, the infrared hybrid method was
developed to separate each stress components. However, it contains the influence of heat
conduction in the infrared stress measurement method. Therefore, heat conduction error will arise in
the infrared hybrid analysis. Then, the new system which corrects the error by an heat conduction
inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be
raised using heat conduction inverse analysis. Furthermore, the accuracy of hybrid method taking
heat conduction into consideration was discussed in comparison with 3-D finite-element analysis
and the 2-D infrared hybrid method.
Eddy Current and Fuzzy Inference to Control Defects Growth in Reinforced Concrete
Authors: Buonsanti Michele , Calcagno S. , Morabito F.C. , Versaci Mario
Published: March 2009

In reinforced concrete, when slits take places, the problem arises to control the growth of
it. If the critical limit is exceeded due to further load increases, the final strength relies on the
integrity of the tight rods. The ability of finding possible defects in these rods and in controlling the
relevant growth is therefore of great importance in structural safety at the ultimate stage. In
particular, thin reinforced concrete structures draw researchers attention to such a point that several
theoretical models have been developed with the aim to reproduce with adequate reliability the real
behaviour, taking into consideration the actual deformability, the rising and spreading of fissuring,
together with the mechanisms and the loads leading to collapsing. In this work, an experimentation
is carried out on a deflect less reinforced concrete specimen, which underwent to rising traction up
to the fissuring. The employed investigation technique is an application of the well-known eddy
current-based methodology. The magnetic fields maps which were got by this way constitute an
electromagnetic representation of the tensional condition of the specimen at the different values of
the applied traction, using the above mentioned experimental database, concerns the extraction of
inferences to predict and assess the growth of defects in reinforced concrete elements similar to the
employed specimen.
Identifying Elastic Properties of Isotropic Materials by Finite Element Analyses and Vibration Data
Authors: Alfano Marco , Pagnotta Leonardo , Stigliano Giambattista
Published: March 2009

The use of non destructive techniques for the elastic characterization of isotropic
materials is continuously increasing and those based on the modal vibration testing of plate-like
specimens is very widespread. In the present paper, an optimized search procedure is proposed
which allows the material constants of isotropic plates to be non-destructively identified from
vibration testing data and using finite element analyses. The identification process is performed by
an optimizing algorithm in which the error function to be minimized depends on the difference
between the natural frequencies obtained by finite element analyses and the measured ones. In order
to verify the proposed identification procedure a comparison with the results reported in literature
has been made.
Peak and Average Temperatures in Adiabatic Shear Band for Thermo-Viscoplastic Metal Materials
Authors: Wang X.B.
Published: March 2009

Gradient-dependent plasticity considering the microstructural effect is introduced into
Johnson-Cook model to calculate the nonuniform temperature distribution in adiabatic shear band
(ASB) and the evolutions of average and peak temperatures in ASB. Effects of initial static yield
stress, strain-hardening coefficient, strain-hardening exponent, strain-rate parameter and
thermal-softening parameter are numerically investigated. The calculated peak temperature in ASB
considering both the plastic work and the microstructural effect is always greater than the average
temperature calculated only using the plastic work. For much lower flow shear stress, the peak
temperature approaches two times the average temperature. The occurrence of phase transformation
in ASB is easier in metal material with higher initial static yield stress, strain-hardening coefficient,
strain-rate parameter and thermal-softening parameter. At much lower flow shear stress or much
higher average plastic shear strain, the phase transformation occurs more easily in material with a
lower strain-hardening exponent. Traditional elastoplastic theory without the microstructural effect
underestimates the peak temperature in ASB so that the experimentally observed phase
transformations cannot be explained.
Leak Behavior of SCC Degraded SG Tubes at a Constant Pressure
Authors: Hwang Seong Sik , Chan Nam Gung , Park Jang Yul , Jung Man Kyo , Kim Hong Pyo , Kim Joung Soo
Published: March 2009

A primary water stress corrosion cracking (SCC) and an outside diameter SCC have
occurred in the steam generator (SG) tubes of nuclear power plants around the world. It is important
to establish the repair criteria for the degraded tubes to assure a reactor integrity, and yet maintain
the plugging ratio within the limits needed for an efficient operation. For assessment and
management of the degradation, it became crucial to understand initial leak behaviors under a small
pressure and leak rate evolution under a constant pressure of SCC flaws. Stress corrosion cracked
tube specimens were prepared by using a room temperature cracking technique, and leak behaviors
of these tubes were measured at room temperature. Water pressure inside the tube was increased
slowly in a step like manner with a designated holding time. Water leak rates just after a ligament
rupture were measured by collecting the leaked water in a plastic container for a designated time. A
leak rate was calculated by dividing the amount of water by the time. Under 3.45 MPa, a small
water droplet was formed, but it did not grow after a 10 minute holding period at a constant
pressure of 3.45 MPa. A throughwall crack seemed to open at around 8.28 MPa (1200 psi). Some
tubes with 100 % through wall cracks did not show a leakage at 10.8 MPa, which is a typical
pressure difference of pressurized water reactors (PWRs) during a normal operation. The higher the
pressure was applied, the larger the rates of increase with the time were. Axial cracks showed a
lower leak pressure than that of the circumferential cracks, which might be from a higher hoop
stress than the axial stress. A large open and long axial crack showed an increasing leak rate with
the time at a constant pressure.
Assessment of In-Plane Size Effect for Nuclear Carbon Steels Using Damage Models
Authors: Chang Yoon Suk , Kim Jong Min , Seok Chang Sung , Choi Jae Boong , Kim Young Jin
Published: March 2009

The present work deals with an applicability of the local approach to assess in-plane size
effects among different sized compact tension (CT) specimens. To characterize ductile crack growth
of typical nuclear materials, SA515 Gr.60 and SA516 Gr.70 carbon steels, finite element analyses
employing modified GTN and Rousselier models as well as fracture toughness tests were carried out.
Material damage parameters were calibrated using standard CT specimens and reflected to predict
fracture resistance (J-R) curves of larger CT specimens. Since comparison results between
numerically estimated J-R curves and experimentally determined ones corresponded well, it is
anticipated that the local approach might be used as a promising tool for ductile fracture evaluation
incorporating the in-plane size effect.
Reliability-Based Optimization for Fatigue Maintenance Planning of Freight Car
Authors: Baek Seok Heum , Lee Kyoung Young , Cho Seok Swoo , Joo Won Sik
Published: March 2009

The performance of bogie decreases according as traveling distance increases. Its causes were
expected to be fatigue, wear, and deterioration. Especially, maintenance coat needs about triple than
manufacture cost during required life in case of container and uncovered freight car. Freight car doesn’t
adapt corrective maintenance which repairs a poor part after a trouble but use preventive maintenance which
fixes a bad part before a trouble. There were a few researches on preventive maintenance such as inspect
affairs and facilities management. They couldn’t estimate the operation reliability on railroad vehicle.
Therefore, this study proposes the preventive maintenance procedure that predict repair period of end
beam for uncovered freight car using reliability function and instantaneous failure rate on the basis of fatigue
test and load history data.
Assessment of Fire Damage to 321 Stainless Steel Equipment in a Chemical Unit
Authors: Zhang Wei , Gao Zeng Liang , Zhang Kangda , Fang Zheng , Lu Xiao Yan , Bao Wei Guang , Zhu Guorong
Published: March 2009

In the present work, the mechanical properties of 321 stainless steel pressure equipments
exposed to an accident fire in a chemical unit were investigated. The performance and
microstructure of this material were described by chemical compositions analysis, tensile test,
scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and
X-ray diffraction (XRD). The experiment results showed that the mechanical properties of the
material were degraded. The grains on the external surface of the fracture became coarse. These
results indicated that serious damage to 321 stainless steel had been induced by extreme heat of the
fire and this pressure vessel could not be used anymore.
Vibration Fatigue Reliability of Lead and Lead-Free Solder Joint by FORM/SORM
Authors: Lee Ouk Sub , Hur Man Jae , Park Yeon Chang , Kim Dong Hyeok
Published: March 2009

It is well-known that the vibration significantly affect the life of solder joint. In this
paper, the effects of the vibration on the failure probability of the solder joint are studied by using
the failure probability models such as the First Order Reliability Method (FORM) and the Second
Order Reliability Method (SORM). The accuracies of the results are estimated by a help of the
Monte Carlo Simulation (MCS). The reliability of the lead and the lead-free solder joint was also
evaluated. The reliability of lead-free solder joint is found to be higher than that of lead solder joint.
Damage Mechanics of Solder Joints under High Current Density
Authors: Basaran Cemal
Published: March 2009

In this paper, Moiré interferometry technique is used to measure the in-situ displacement
evolution of lead-free solder joints under high density (104A/cm2). An electromigration constitutive
model is developed to simulate deformation of lead-free solder joint under current stressing. The
simulation predicts Moiré interferometry measurements in both spatial distribution and time history
evolution, which indicates that the model is reasonably good for predicting the mechanical behavior
of lead-free solder joints under electric current stressing.
The Effect of a Free Drop Impact on the Bolted Joint of the Radioactive Transport Package
Authors: Kim Dong Hak , Seo Ki Seong , Lee Ju Cahn
Published: March 2009

In this study the effect of a free drop impact on the bolted joint of the transport package of
radioactive material was studied under various directions. A drop test of a type A or a type IP transport
package of radioactive material should be conducted under normal transport conditions. After a drop
test the radioactive content of the transport package should not be loss or dispersal. A bolt tension
during a drop impact under various directions was measured using a force sensor. And the torque to
loosen a bolt was measured after the tests. A bolt tension measured by the tests was compared with the
result of a finite element analysis. The effect of the drop direction was examined. The vertical drop
directions shows larger bolt tension than horizontal drop. For the torque to loosen a bolt, a horizontal
drop condition shows larger value than a vertical drop direction.
Dissimilar Metal Welding of Austenite Stainless Steel and Carbon Steel Using Nd:YAG Laser a Continuous Wave
Authors: Shin Ho Jun , Yoo Young Tae , Shin Byung Heon , Kim Ji Hwan
Published: March 2009

Dissimilar metal welding (DMW) are used widely in various industrial applications due
to the practical importance from the technical and economic aspect. However, DMW have several
fabricative and metallurgical drawbacks that can often lead to in-service failures. For example, the
most pronounced fabrication faults are hot cracks. Recently, DMW have used the several of heat
source to decrease such as faults. Laser welding process has, in recent years, attracted more
attention due to its special features: a small heat-affected zone and narrow weld bead due to the low
heat input; welding at high speed; welding can be carried out in areas of difficult access; contactless
energy transfer; welding in an exact and reproducible manner; possibilities for automation and
robotization, and welding performed in various atmospheres. In this paper, the weldability on
dissimilar metal welding of austenite stainless steel and carbon steel using Nd:YAG laser with a
continuous wave was experimentally investigated.
Application of Finite Element Analysis for the Prediction of the Fatigue Lifetime of Spot Welds with Triple SPCC plates
Authors: Choi Byoung Ho , Joo Dong Ho , Song Sam Hong
Published: March 2009

The fatigue characteristic of triple spot welded SPCC plates with the variation of the
thickness and the geometry under tensile-shear loading is studied by finite element analysis (FEA)
and the obtained data is compared with experimental data. Using 3-D solid element model and 3-D
beam-shell model, the maximum equivalent stress and the beam deformation angle (BDA) for various
thickness and geometry is studied. The linear relation between crack opening angle (COA) from
experiment and the BDA from FEA for beam-shell model is represented, and the empirical prediction
of fatigue lifetime is proposed using the relation between COA and BDA.
Effect of Heating Rate on Al Bonding in Air by Inserted A5056 Disk
Authors: Kawakami Hiroshi , Kimura Keiko , Kondo Satoshi , Suzuki Jippei
Published: March 2009

Al bonding in air by inserted A5056 was investigated in this study. Heating rate in
thermal history of bonding process may have the relation with the growth of Al oxide film and the
deformation of bonding surface by softening. Both of phenomena affect the joinability and the
mechanical properties of bond. Al bonding in air was carried out by several heating rate. Growth of
Al oxide film significantly suppressed the progress of bonding in air by low heating rate, 1K/s.
Decrease of deformation of bonding surface suppressed also the progress of bonding by high
heating rate, 10K/s. In case of medium heating rate, 5K/s, good joinabilty of Al bonding in air was
obtained by the medium growth of oxide film and the deformation of bonding surface.
Laser Welding Characteristics of Cold Rolled Carbon Steel Utilize Continuous Wave Nd:YAG Laser
Authors: Shin Byung Heon , Yoo Young Tae , Shin Ho Jun , Kim Ji Hwan
Published: March 2009

Laser welding process is widely used in the industrial area due to its less affects to base
metal than general welding. Laser welding has characteristics that highly affect ratio, deeply
penetration depth and small heat affected zone(HAZ) due to its in a short time melting and then
solidification by a high energy absorption rate. The objective of this research work is to investigate
the optimum conditions of a cold rolled carbon steel(SCP1) in a laser welding process using a
Nd:YAG laser with a continuous wave(CW). The determination of optimum conditions were
performed to change the laser power, beam speed, focus length and then carry out an butt welding.
From the results of the investigation, it has been shown that the optimal welding condition without
defects in the vicinity of the welded area and with a good welding quality is 1325W of the laser
power, 1.4m/min of laser welding speed and 0mm of focus position.
Modeling of Weld Beads for Laser-GMA Hybrid Welding
Authors: Kim Cheol Hee , Kang Nam Hyun , Chae Hyun Byung , Kim Jeong Han
Published: March 2009

For laser-GMA hybrid welds, the relationship between the process parameters and bead shapes was
investigated by using the experimental design and the non-linear regression. The weld beads were
fitted by two quadratic functions. By the statistical analysis, the primary bead was mainly affected by
GMA welding parameters and the root bead was mainly by laser welding parameters. The root bead
shaped deeper penetration and shallower width, as the laser power increased for the constant arc
power. High laser power resulted in the martensite phase, therefore exhibiting the sudden increase of
hardness as approached to the fusion line of the root bead.
Microstructural Factors Governing Mechanical Properties in Friction Stir Welds
Authors: Sato Yutaka S. , Kokawa Hiroyuki
Published: March 2009

Friction stir welding (FSW) is a solid-state joining process. During FSW, microstructure
drastically changes in local region of the workpiece by introduction of frictional heat and severe
plastic deformation arising from rotation of the welding tool, which results in inhomogeneous
microstructural distribution in the welds. To maintain high reliability of the structure produced by
FSW, precise understanding of microstructural factors governing weld properties is required. In the
present paper, microstructural factors governing mechanical properties, especially hardness profile
and tensile properties, of friction stir welded Al and Mg alloys are reviewed.