bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on the Dynamic Splitting Tensile Behaviour of Concrete
Authors: Zhang Li Jun , Yan Xiao Peng , Wang Zhi Hua , Ma Hong Wei
Published: March 2009

Many structures and buildings such as nuclear power station and chemical plant are often
subjected to impact and explosive loadings. The understanding of material response to highamplitude,
short-duration, impulse loads is very important, dynamic behavior of concrete under
high strain rate has been paid much attention to. In the present paper, experimental study on the
dynamic tension behavior of concrete is carried out. Based on the former theoretical introduction,
dynamic splitting tensile tests at different strain rates are conducted on 74mm diameter concrete
specimens in a Split Hopkinson Pressure Bar to study the effect of strain rate on the dynamic
tension behavior of concrete. The mechanism and speed of crack propagation of concrete cylinder
planar surface in dynamic splitting tensile test are discussed briefly.
New Technique for “Cullet” Generation of Glass Bottles by Using Underwater Shockwave
Authors: Sakamoto Hidetoshi , Kawabe Shinjiro , Satoh Kazuo , Himeno Masahiro , Itoh Shigeru
Published: March 2009

As the application technique for glass bottle’s recycling system, a new “Cullet”
generation method by using underwater shock wave was proposed. This small fragmentation
technique of glass bottles has a lot of excellent advantages such as the simplification of process by
simultaneous cleaning and crushing operation, the high collect rate of “Cullet” and so on. In this
study, the relation between of the explosive conditions and “Cullet” sizes were clarified and the
high speed fracture process of glass bottle was observed by framing photograph of high speed
image converter.
Elastic Transverse Impact on Beams
Authors: Goldar Dulal
Published: March 2009

Present investigation were carried out to study photoelastically the stress distributions in
a simply supported beam with over- hangs subjected to a low velocity central- and quarter- spanimpact
loadings by light strikers keeping beam/ striker weight ratio constant (2.675), and then
comparing the results so obtained with those in similar simply supported beams made of other
materials subjected to central- impact loadings from an analysis of dynamic strain gauge
data. Interesting new findings were obtained from the results of the present investigation and also
from results reported in the literature in this respect.
Introduction.
In modern times dynamic stress analysis is becoming increasingly important for various
engineering applications. Although significant amount of insight in these respects have been
developed, the subject being rather intricate would continue to attract of more research workers in
future.
A beam is a common structural element, and in several applications, simply supported beams
with over- hang are employed in practice. Transverse and longitudinal bridge girders and chassis
of rails- and road- wagons are some of the typical applications of the same. Here, photoelastic
technique was employed to determine dynamic stress distributions in a model simply supported
beam with over- hang.
Fibre-Reinforced Polymers under Impact Load
Authors: Koenig Ch.R. , Mueller D.H. , Mueller J. , Calomfirescu Mircea
Published: March 2009

Structural failure of fibre-reinforced polymers (FRP) caused by impact is an important factor in product development
for the aircraft industry. Therefore it is necessary to obtain knowledge of the mechanisms and of the material loading
during and shortly after an impact load. On account of this a Finite-Element-Model was developed with the goal to
deduce design rules for impact tolerant composite materials.
To verify and validate the Finite-Element-Model it is essential to have information of the state of stress on the surface
of the FRP shortly after the impact. An impact test device was developed at the University of Bremen. The time
variable, stress and strain conditions in composite plates are measured using photoelastic technique, strain gauges and
holographic interferometry.
Dynamic Response and Fracture of High Strength Boride/Alumina Ceramic Composite
Authors: Cao Dong Feng , Liu Li Sheng , Zhang Jiang Tao
Published: March 2009

Dynamic response and fracture of high strength boride/alumina ceramic composite were
investigated by split Hopkinson pressure bar (SHPB) experiment in this paper. The compressive
stress–strain curves and dynamic compression strength of the composites were tested. The surface’s
microstructure of fractured composites were examined by using scanning electron microscope
(SEM) to investigate the fracture mechanism. The results show that boride/alumina has high
dynamic compressive strength and high Young’s modulus. The main fracture mode of the material is
the fracture of the ceramic grains. The micro-voids and flaws, generated during the sintering and
manufacturing of material and mechanical process of specimen, decrease the strength of the material
because they provide the source of crack expansion when the material undergoes the dynamic
loadings.
Nonsymmetric Groove Pattern Design for Precise Micro-Spindles
Authors: Oh Dong Ho , Lee Nam Hoon , Koo Ja Choon , Choi Hyeon Ki , Choi Yeon Sun
Published: March 2009

As the fluid dynamic bearing spindles are to be actively adopted to various small form
factor mobile applications, mechanical specifications for the motors have been aggressively changed
to pursue the fierce information technology sector market trend. One of the major technological
challenges for the spindles to be successfully employed in the applications is the reduction of power
consumption since the most of the mobile applications operate with a limited power source at
relatively lower voltage. Recognizing implication of the power consumption that of course affects
stiffness of the spindle, few of options for mechanical designers are available but either lowering
rotational speed or adopting thinner lubricant. In the present work, a novel design solution for
alleviating side effect of the lower stiffness spindle is introduced and verified.
An Estimation of the Dynamic Buckling Load for the Spacer Grid of Pressurized Water Reactor Fuel Assembly
Authors: Jeon Sang Youn , Lee Young Shin
Published: March 2009

This study contains an estimation of the dynamic buckling load for the spacer grid
of fuel assembly in pressurized water reactor. Three different estimation methods were
proposed for the calculation of the dynamic buckling loads of spacer grid. The dynamic
impact tests and analyses were performed to evaluate the impact characteristics of the spacer
grids and to predict the dynamic buckling load of the full size spacer grid. The estimation
results were compared with the test results for the verification of the estimation methods.
Study on the Circular Fracture in MFCG Armatures Expansion
Authors: Chen Xi , Jiao Qing Jie
Published: March 2009

The high-speed photography and the non-linear dynamics engineering program
LS-DYNA are conducted to research on Al and Cu armatures expansion process under the drive of
pressed composite B explosive with the charge method of several-section. A special experiment
system with an equipment of blocking off armature fracture flashing light is built, and a thorough
analysis of the “circular fracture” phenomena has been made: For the air gap existence, there is a
difference between the axial movement velocity of the armature joint position wall and other
positions wall. The upward wall forces the joint position wall and then the “circular fracture”
appears. Some conclusions about Magnetic Flux Compression Generator design are obtained.
Experimental Study on the Fluctuating Pressure Acting on a 5x5 Partial Fuel Assembly in a Parallel Flow
Authors: Lee Kang Hee , Kang Heung Seok , Yoon Kyung Ho , Song Kee Nam
Published: March 2009

A 5x5 partial fuel assembly was used for a comparative design evaluation test of a
newly developed spacer grid from a mechanical/hydraulic vibration aspect. Axial flow pattern
along this rod bundle in the test was very complex due to the intermediate spacers and the
mixing vane; Understanding of this flow field of a dynamic pressure is a preliminary step for a
theoretical analysis of a vibratory behavior of a partial fuel assembly. Since a fluctuating
pressure induced by the randomly-varying flow turbulence cannot be accurately predicted by an
analysis alone, it has to be measured directly on the surface over the rod or in an accessible
vicinity of the bundle. In this study, the fluctuating pressure acting on a partial fuel assembly
with a spacer grid and a mixing vane was measured. The measured PSD showed different
spectral features from the results of the literatures and had a series of periodic pulsations with
sidebands over the specific frequency ranges; it is believed that the periodic components in the
PSD have to do with the design of the spacer grid and the mixing vane. And, the exciting force
function for the theoretical analysis of a partial fuel assembly with spacers and a mixing vane
was estimated as a possible PSD form.
FEA-Based Design and Fabrication of Functionally Graded Materials
Authors: Shin Ki Hoon , Cheong Seong Kyun
Published: March 2009

Functionally Graded Materials (FGMs) are composite materials that have continuous
material variation along with geometry. This paper introduces a method for FEA-based design and
layered manufacturing (LM) of FGMs. An FGM solid model is first created by referring to the
libraries of primary materials and composition functions. The model is then discretized into an
object model onto which appropriate material properties are mapped. Next, the object model is
adaptively meshed and converted into an FE model. FEA using ANSYS is finally performed to
estimate stress levels. This FEA-based design cycle is repeated until a satisfactory solution is
obtained. The object model is then fed to the fabrication system where a process planning is
performed to create instructions for LM machines. As a laser-based LM method, Direct Metal
Deposition (DMD) at the University of Michigan is briefly described. A specific example (FGM
pressure vessel) is shown to illustrate the entire FEA-based design and DMD fabrication cycle.
Effect of Air-Coupled/Conventional Ultrasound Waves on Resin-Infiltrated Time of Wood Natural Materials
Authors: Yang In Young , Kim Sun Kyu , Lee Kil Sung , Hsu David K. , Park Je Woong , Im Kwang Hee
Published: March 2009

Air-coupled ultrasound is a non-contact technique and has obvious advantages over
water-coupled experimentation. Especially, wood materials are very sensitive to water and
inspection without any coupling medium of a liquid is really needed to wood materials due to the
permeation of coupling medium such as water. In this work, it is desirable to perform contact-less
nondestructive evaluation to assess wood material homogeneity. A wood material was
nondestructively characterized with non-contact and contact modes to measure ultrasonic velocity
using automated data acquisition software. We have utilized a proposed peak-delay measurement
method. Also through transmission mode was performed because of the main limitation for aircoupled
transducers, which is the acoustic impedance mismatch between most materials and air.
The variation of ultrasonic velocity was found to be consistent to some degree with those in
infiltrated area for air-coupled and conventional scan images. Through-transmission scans for aircoupled
and conventional UT were used based on both amplitude and time-of-flight images.
Finally, results using a peak-delay measurement method well somewhat corresponded to ultrasonic
velocities of the pulse overlap method.
Modification of Coherent Gradient Sensing (CGS) to Accurately Get the Fringe Order
Authors: Zhang Ya Ping , Fan Zhi Gang , Xu Shi Wei
Published: March 2009

In this paper, a novel optical method, namely, Coherent Gradient Sensing (CGS) is used
to study the fracture properties of IR window materials in the guidance missile. CGS can produce
high contrast fringes and provide some degree of control on the sensitivity of measurement during
experiment. It is highly attractive for solid mechanics applications, especially to new materials, such
as IR window materials. But the accuracy of the fringe order in the CGS interference image will
deeply influence the precision of experiment. Because of the different optical principle from other
method, the fringe order of CGS can’t be obtained through the phase-shift technology. To satisfy
the precision request of IR window materials, a kind of modified CGS method, loading CGS
method is introduced and analyzed, which can accurately obtain the fringe order of random position
in the CGS interference image. This method doesn’t need additional optical set-up and complicated
image processing techniques, but only need two CGS interference images under different loading.
Static fracture experiments of ZnS show that this method can evidently improve the precision of the
CGS method.
Analysis of Mechanical Effects of Plant’s Roots on Slope Reinforcement
Authors: Chen Jing Xi , Hu Shuang Shuang , Zhang Guang
Published: March 2009

To quantitatively evaluate the mechanical effect of plants’ roots on slope reinforcement,
this paper probes into the application of composite material theory and finite element method (FEM)
to analysis of mechanical properties of soil and soil/root respectively. Soil with herbage roots is
regarded as a kind of special composite material, soil is matrix and root is intensifier. Comparing to
the test result, the result obtained by composite material model is not perfect but can be used to
estimate the effect of roots on soil reinforcement. Moreover, the result obtained by FEM analysis
confirms the effect of root on soil reinforcement, especially along the direction of root length.
Tensile and Shear Properties of Stitched Laminates in Hygrothermal Environment
Authors: Huang Tao , Jiao Gui Qiong , Xu Ting Ting
Published: March 2009

Stitched laminates is a low-cost structure panels with carbon fiber face sheets, and
through-the-thickness Kevlar stitching. Through-the thickness stitching is proposed to increase the
interlaminar strength and damage tolerance of composite laminates. Tensile and shear experiment
of stitched laminates at room temperature and in hygrothermal environment was carried out
according to corresponding national standards. Experiment results indicate that the tensile and shear
modulus and strength were much reduced by the stitching, especially in hygrothermal environment.
Micrographs of fracture appearance showed that the exist of resin-rich area is the source of crack
both in normal room temperature environment and hygrothermal environment. It is concluded that
hygrothermal environment and initial crack in resin-rich area were prime reason for performance
lost of stitched laminates.
Strength of Composite Laminated Bolted Joint Subjected to a Clamping Force
Authors: Choi Jin Ho , Lee Young Hwan , Kweon Jin Hwe , Che Woo Seong
Published: March 2009

As these composites have become more popular, composite joint design has become a
very important research area, as these joints are often the weakest parts of composite structures. In
this paper, the strength of a composite laminated bolted joint being subjected to a clamping force
was tested and predicted using the FAI (Failure Area Index) method. The strengths of composite
joints subjected to clamping forces on different geometric shapes and dimensions were predicted
using the FAI method, and the results were compared with experimental results. From the tests and
analyses, the strength of a given composite laminated bolted joint subjected to a clamping force
could be predicted within 22.5% via the FAI method.
A Study on Bore-Sighting for the Error Reduction of the XK11
Authors: Yeo Woon Joo , Chae Je Wook , Lee Chan , Choi Eui Jung , Lee Jun Ho
Published: March 2009

This study is launched to get exact bore-sighting value in the process of assembly for XK11.
Image processing method with Charged Coupled Device camera is chosen for the Error reduction of
bore-sighting. The results of this method by using a CCD camera and the Testing Target Method
are described in this paper. After we confirm the performance of the Dual-Barrel Weapon and that
of the Firing Control System in the Dual Barrel Weapon System, the bore-sighting which is a part
of the process in the system assembly is accomplished. In this process, the position of the barrel is
identified by using the Testing Target Method that is an existing bore-sighting method. Then the
fixing line of the Firing Control System is checked by a Day-Optical part. The precision of the boresighting
is required within 1 mil, however the manual method using the human eyes makes it worse.
Therefore CCD camera is installed in the eyepieces. Next, we can get the image of the sighting and
the center coordinate values of the laser-pointer from each barrel by image processing method.
Required bore-sighting value is calculated from the eccentricity of the center coordinate. Finally,
we will plan to adopt this result in the assembly process of XK11.
Characterization of Polycarbonate/Multiwalled Carbon Nanotube Composites
Authors: Kim Hun Sik , Park Byung Hyun , Kang Min Sung , Yoon Jin San , Jin Hyoung Joon
Published: March 2009

Polycarbonate/multiwalled carbon nanotubes (PC/MWNT) nanocomposites with
different contents of MWNT were successfully prepared by melt compounding. The mechanical
properties of the PC/MWNT nanocomposites were effectively increased due to the incorporation of
MWNTs. The composites were characterized using scanning electron microscopy in order to obtain
the information on the dispersion of MWNT in the polymeric matrix. In case of 0.3 wt% of MWNT
in the matrix, strength and modulus of the composite increased by 30% and 20%, respectively. In
addition, the dispersion of MWNTs in the PC matrix resulted in substantial decrease in the electrical
resistivity of the composites as the MWNTs loading was increased from 1.0 wt% to 1.5 wt%.
A Study on the Structural Stress Analysis of the Steel and the GFRP Laminated Composite Cylindrical Shell with a Stiffened Circular Cutout
Authors: Lee Young Shin , Lee Je Jun , Kang Youn Ki , Song Sun Young
Published: March 2009

The strain distribution around the unstiffened and stiffened circular cutout of the isotropic
stainless steel (ANSI type 304) and the GFRP laminated composite cylindrical shells subjected to
axial compression are studied. The experimental results are obtained and compared with numerical
analysis. In experiment, the strain is measured around the circular cutout by strain measuring
system under the axial uniform compression loading. The numerical analysis is performed by the
commercial finite element code ANSYS. The strain concentration factor (SCF) is defined to
investigate the strain concentration around the circular cutout. The SCF of the stainless steel
cylindrical shell with a stiffened cutout is decreased 39% in experiment and 50 % in numerical
analysis. The SCF of GFRP laminated composite cylindrical shell is decreased 22% in experiment
and 31 % in numerical analysis.
Optical Retardation Measurement Using a Zeeman Laser
Authors: Lin Jing Fung , Lo Yu Lung
Published: March 2009

This paper presents a new optical configuration for measuring the phase retardation of
optical linear birefringent materials. Phase retardation is measured by a heterodyne light source,
which is generated by a Zeeman laser. The measurement system has advantages as a simple optical
setup, high stability, small size, and portable owing to the configuration and the use of a Zeeman
laser. Using the ratio of amplitudes from two measured heterodyne signals, a simple algorithm can
obtain the phase retardation directly. Moreover, we can extend dynamic range of the phase
retardation measurement to be 0 180 successfully. According to the experimental results, the
average absolute error for the phase retardation of λ / 4 -wave plate sample is determined to be only
2.7 %.
In Situ Fast Temperature Measurement of Silicon Thin Films during the Excimer Laser Annealing
Authors: Moon Seung Jae
Published: March 2009

The formation and growth mechanism of polysilicon grains in thin films via laser
annealing of amorphous silicon thin films are studied. The complete understanding of the
mechanism is crucial to improve the thin film transistors used as switches in the active matrix liquid
crystal displays. To understand the recrystallization mechanism, the temperature history and liquidsolid
interface motion during the excimer laser annealing of 50-nm thick amorphous and polysilicon
films on fused quartz substrates are intensively investigated via in-situ time-resolved thermal
emission measurements, optical reflectance and transmittance measurements at near infrared
wavelengths. The front transmissivity and reflectivity are measured to obtain the emissivity at the
1.52 μm wavelength of the probe IRHeNe laser to improve the accuracy of the temperature
measurement. The melting point of amorphous silicon is higher than that of crystalline silicon of
1685 K by 100-150 K. This is the first direct measurement of the melting temperature of amorphous
silicon thin films. It is found that melting of polysilicon occurs close to the melting point of
crystalline silicon. Also the optical properties such as reflectance and transmittance are used to
determine the melt duration by the detecting the difference of the optical properties of liquid silicon
and solid silicon.
Realization of a Chip-Level Batch Process Chemical Plant with Quantitative Performance Evaluation
Authors: Joeng Eun Ho , Arakawa Takahiro , Kim Kyung Chun , Boo Jung Sook , Ko Jong Soo , Shin Bo Sung , Shoji Shuich , Go Jeung Sang
Published: March 2009

This paper presents a droplet-based micro chemical plant with the chemical preparation,
volume-fragmentation reaction and continuous separation of product with quantitative evaluation.
It consists of a cross-channel network to prepare the droplet-based chemicals, a bifurcation channel
to obtain the volume fragmentation of droplet and the pelican mouth separator to extract the
reaction-completed chemicals.
Interfacial Residual Stress Measurement of SiC/Epoxy Composites by Microphotoelastic Method
Authors: Yang Xin Wei , Ji Xin Hua , Xing Yong Ming , Qin Yu Wen
Published: March 2009

Interfacial residual stresses play an important role in the mechanical
properties. In this paper, the interfacial residual stresses of SCI/Epoxy composites
were determined using a novel technique-microphotoelastic method. The thermal
residual stress field was also numerically simulated using a finite element software
MSC.MARC. The difference and the similarities between the experimental results and
the simulation of FEM analysis were discussed and the availability of the method was
preliminarily certified.
Size Effect on Tensile Strength of Surface-Micromachined Al-3%Ti Thin Films
Authors: Park Jun Hyub , Myung Man Sik , Kim Yun Jae , Lee Chang Seung , Choa Sung Hoon , Che Woo Seong
Published: March 2009

A new tensile tester using an electromagnetic-force actuator (voice coil) was developed
to measure the mechanical characteristics of surface-micromachined thin film materials. The tester
has a load cell with maximum capacity of 0.5N and a non-contact position measuring system based
on the principle of capacitance micrometry with 0.1nm resolution for displacement measurement.
The tester was applied for tensile testing of Al-3%Ti thin films with dimensions of 1000μm long,
50-480μm wide and 1.0 and 1.1 μm thick. The Al-3%Ti is commonly used in RF(radio frequency)
microelectromechanical systems(MEMS) switch. The specimen with holes and bridges was
designed for easy tensile test. The holes at center of grip end are able to make alignment and
gripping easy. The bridges are to remove the side supports easily and extract specimen from wafer
without sawing. It was found that the mean tensile strengths of Al-3%Ti are 140-380MPa,
depending on the width of specimens and converging to a certain tensile strength as the width
decreases.
Synthesis of Vertically Aligned Carbon Nanotubes by dc PECVD
Authors: Bang Yun Young , Je Tae Jin , Whang Kyung Hyun , Chang Won Seok
Published: March 2009

Chemical vapor deposition (CVD) is one of the various synthesis methods that have been
employed for CNT growth. In particular, Ren et al reported that large areas of vertically aligned
multi-wall carbon nanotubes could be grown using plasma enhanced chemical vapor deposition
(PECVD). In the present study, we synthesized aligned CNT arrays using a direct current (dc)
PECVD system. The synthesis of CNTs requires a metal catalyst layer, etchant gas, and a carbon
source. In this study, the substrate consisted of Si wafers with 10, 30, and 50 nm Ni-sputtered film.
Ammonia (NH3) and acetylene (C2H2) were used as the etchant gases and carbon source,
respectively. NH3 pretreatment was processed using a flow rate of 180 sccm for 10 min. CNTs were
grown on pretreated substrates at 30% C2H2:NH3 flow ratios for 10 min. Carbon nanotubes with
diameters ranging from 60 to 80 nanometers and lengths of about 2.7 μm were obtained. Vertical
alignment of the carbon nanotubes was observed by FE-SEM.
Parallel Computation of Large-Scale Molecular Dynamics Simulations
Authors: Kwon Sung Jin , Lee Young Min , Im Se Young
Published: March 2009

A large-scale parallel computation is extremely important for MD (molecular dynamics)
simulation, particularly in dealing with atomistic systems with realistic size comparable to
macroscopic continuum scale. We present a new approach for parallel computation of MD
simulation. The entire system domain under consideration is divided into many Eulerian
subdomains, each of which is surrounded with its own buffer layer and to which its own processor
is assigned. This leads to an efficient tracking of each molecule, even when the molecules move
out of its subdomain. Several numerical examples are provided to demonstrate the effectiveness
of this computation scheme.
Design of a Rubber Membrane under Substrate for Nanoimprint Lithography Process
Authors: Han Seung Woo , Seo Ki Jeong , Lee Jae Jong , Lee Seung Woo , Lee Hak Joo , Kim Jung Yup
Published: March 2009

Nanoimprint lithography is a promising technology to produce sub-100 nm scale features
on silicon chips. One of key issues in the nanoimprint lithography is how to make uniform contact
between the stamp and the substrate on a large area. In this study a rubber membrane unit under
substrate is introduced to resolve this problem. Two layers of membrane were designed to consider
air flow in the middle of resist on a silicon wafer. The geometry design for accomplishing uniform
contact was carried out using finite element analysis. The material modeling of hyperelastic
properties of rubber is characterized by the Mooney-Rivlin strain energy functions. Material
constants in the strain energy functions are able to be determined via the curve fitting of
experimental stress-strain data. Simple tension and equi-biaxial tests were performed to determine
the material constants. To evaluate the effects of a rubber membrane unit, nanoimprint lithography
process with it was executed. We could confirm that a distinct improvement of uniform contact was
shown and air flow problem was solved during the process.
Using Nanoindentation and Nanoscratch to Determine Thin Film Mechanical Properties
Authors: Chang Rwei Ching , Chen Feng Yuan , Sun Chang En
Published: March 2009

This work uses nanoindentation and nanoscratch to measure the mechanical properties of
evaporation copper thin films. The thin film is deposited on a silicon wafer substrate by using the
physical vapor deposition method provided by a resistive heating evaporator. The mechanical
properties are then determined by indentation test and lateral force test produced by nanoindenter
and nanoscratch. The results show that, as the copper thin film is 500nm in thickness and the
indentation depth increases from 100nm to 400nm, the Young’s modulus increases from 151GPa to
160GPa while the hardness increases from 2.8GPa to 3.5GPa. Moreover, both the Young’s modulus
and the hardness decrease as the thickness of the thin film increases. Besides, the nanoscratch
results show that the friction factor also increases as the scratch depth increases, and a thinner film
thickness makes a larger friction factor. The results represent the substrate has a significant effect
on the mechanical properties of the thin films.
The Size and Morphology of Fine CaB6 Powder Synthesized by Nanometer CaCO3 as Reactant
Authors: Zhang Lin , Min Guang Hui , Yu Hua Shun , Chen Hong Mei , Feng Gang
Published: March 2009

Based on the CaCO3-B4C-C system to prepare calcium hexaboride (CaB6) powder, the
influence of B4C size on the CaB6 powder was investigated in this paper, in which micro-sized B4C
in various size and nano-sized CaCO3 were as main raw materials. XRD and SEM were used to
characterize the phase pattern, size and morphology of CaB6 powder particles respectively. Laser
particle size analyzer was employed to determine the size distribution of CaB6 particles. It was
found that the size of B4C had a dominant effect on the size and distribution of CaB6 powder
particles. When B4C particles were much coarser than CaCO3, the CaB6 synthesized appeared as
aggregates which size relied on B4C, however, the size of every CaB6 particle was determined by
CaCO3. When B4C particles size was fine to several microns, the CaB6 particles synthesized were
dispersive and the size of them has great relation to B4C. Synthesis models were also established to
describe various reaction processes.
Computation of Fluid Film Pressures by Measuring the Elastohydrodynamic Lubrication Film Thickness with Nano-Scale Resolution
Authors: Jang Si Youl
Published: March 2009

Many EHL (elastohydrodynamic lubrication) experiments have been performed with the
regard to measuring the film thickness variations according to contact conditions, such as contact
load, sliding-rolling ratio, contact accelerations for the verification purpose of lubricant
characteristics. The measured images of film thickness by the interferometry system are easily
converted into film thickness values even both in nanometer scale and resolution with the help of
image processing technology.
However, only the measurement of the EHL film thickness is not enough to verify the
lubricant characteristics under the various contact conditions, because the lubricant is under very
high contact pressures above 500MPa, where the lubricant is suddenly solidified and is no longer
considered as a fluid itself. In this work, the EHL fluid film pressures are computed from the
measured interferometric image of contact film thickness ranging from 10nm to several hundred
nano meter, which should be taken with nano-scale resolution. The image processing technique
makes it possible to convert the measured film thickness into contact fluid film pressures if the
contact geometry and material properties are known. Without the nano-scale resolution for the
measured film thickness, the converting computation from the measured film thickness to fluid film
pressure is not possible due to the severe noises of interferometric image over the contact area.
Measuring technology of the EHL film thickness with nano-scale is also explained with regards to
nano scale resolution.
Nano Manufacturing Using Fountain Pen Nano-Lithography with Active Membrane Pumping
Authors: Lee Young Kwan , Lee Jin Hyoung , Lee Sung Kun , Lee Sang Hwan , Kim Youn Jea , Kim Hun Mo
Published: March 2009

In this paper, nano manufacturing using the FPN (Fountain Pen Nano-Lithography) with
active membrane pumping is investigated. This FPN has integrated pumping chamber, micro
channel, and high capacity reservoir for continuous ink feed. The most important aspect in this
probe provided the control of fluid injection using active membrane pumping in chamber. The flow
rates in channel by capillary force are theoretically analyzed with two different working fluids,
DPD (diphenyldichlorosilane) and water, including the cantilever deflection and the control of mass
flow rates by the deflection of membrane. The theoretical results are compared with numerical ones
that calculated by commercial code, FLUENT.
Mechanical Performance of Silk-Based Structural Composites
Authors: Cheung Hoi Yan , Lau Alan Kin Tak
Published: March 2009

With the strong emphasis on environmental awareness, it has brought much attention in
the development of recyclable and environmentally sustainable composite materials since the last
decade. Environmental legislation as well as consumer demand in many countries is increasing the
pressure on manufacturers of materials and end-products to consider the environmental impact of
their products at all stages of their life cycle, including recycling and ultimate disposal. Silk fibers,
spun out from silkworm cocoons, consist of a fibroin core surrounded by a protein layer called
"sericin", and these fibers are biodegradable and highly crystalline. It has been known that these
fibers have higher tensile strength and are more predictable in failure than glass and synthetic
organic fibers. Recently, few preliminary studies have reported that the use of these silks, as microreinforcements
to replace un-recyclable carbon and glass fibers for polymeric-based structural
composite materials can enhance their mechanical and thermal properties, with reducing the amount
of un-decomposable wastes and pollutants. In this paper, the mechanical properties of silk-based
epoxy composites formed by different controlled manufacturing parameters are elaborately studied.
Feasible Evaluation of Flow Properties and Stress State of Structural Materials Using Instrumented Indentation Tests
Authors: Kim Ju Young , Lee Jung Suk , Lee Kyung Woo , Kim Kwang Ho , Kwon Dong Il
Published: March 2009

Flow properties and stress state are indispensable factors for safety assessment of
structural materials in operation, which were evaluated using instrumented indentation tests (IITs).
Flow properties were obtained by defining representative stress and strain, and IIT results for 10
steel materials were discussed by comparing with those from uniaxial tensile tests. The indentation
load-depth curve is significantly affected by the presence of residual stress, and the stress-induced
load change was converted to a quantitative stress value. The stress state of a friction stir-welded
joint of API X80 steel was evaluated and compared with that measured by energy-dispersive X-ray
diffraction.
Experimental Study on Electro-Magneto-Mechanical Behaviour of Electromagnetic Solids
Authors: Fang Dai Ning , Zhao Xu Jun , Pei Yong Mao , Liu Zhan Wei , Li Fa Xin , Feng Xue
Published: March 2009

New experiment systems that can offer electromechanical and electromagnetic
coupling loads were established. Measurement skills and technologies under coupling
loads have been developed. The experimental difficulties and technical problems,
such as insulation, discharge, compressive testing of brittle ferroelectrics and so on,
were well resolved. The constitutive experiments of piezo/ferroelectrics or
ferromagnetic materials were carried out. Moiré Interferometry was applied to the
measurement of transformation of the crack tip in ferroelectric ceramics under
coupling loads. The deformation concentration near the internal electrode tip caused
by non-uniform electric field was investigated by means of Digital Speckle
Correlation Method (DSCM). With an aim to accomplish both measurements of
constitutive response of the magnetostrictive materials and the fracture experiments
of general soft ferromagnetic materials, a magnetomechanical-coupling testing setup
was established, which is controlled by an industrial PC. The software was
programmed to monitor the testing process and to deal with the acquired data. The
characteristic curves of ferromagnetic materials, such as TbxDy1-xFe2 alloys, were
measured, including the hysteresis loops, the magnetostriction curve and stress-strain
curve.
The Design of a New Ultrasonic Horn for Flip-Chip Bonding
Authors: Wang Wei Chung , Chen Shing , Liu Chun Hsien , Ni Chun Yao
Published: March 2009

In the manufacturing process of flip-chips, ultrasonic bonding has been widely used.
In the past, however, the ultrasonic horn was designed to move horizontally while the bonding force
was applied vertically, the motion control of the horn thus cannot be controlled accurately. In
addition, non-coplanar effects were unavoidably occurred and the quality of bonding became
unacceptable. In this paper, the non-coplanar phenomenon between the horn and the substrate was
attempted to improve by designing the horn with the following features:
1. The resonant mode of the horn is purely longitudinal;
2. The contact surface between the horn and the flip-chip in the substrate remain plane;
The finite element method (FEM) was used to design the ultrasonic horn with the above features.
In the future, the amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) will be
used to verify the FEM results.
Micro Via-Hole Punching of LTCC-PET Double Layer Sheets
Authors: Rhim Sung Han , Baek Seung Wook , Oh Soo Ik
Published: March 2009

In low temperature co-fired ceramic (LTCC) packaging which offers a good performance
to produce multilayer structures with electronic circuits and components, the via-hole fabrication of
LTCC ceramic-PET double layer sheets (green sheets or green tapes) by micro-scale punching
plays an important role in providing an electric path for the interconnection between layers.
Although conventional punching has been used widely and many researchers have provided useful
insights of the process, they are restricted to the punching of single layer material. This paper
discusses the characteristic of micro via-hole punching of double layer sheets and the optimum
process condition for via-holes of good quality. Workpiece (double layer sheet) used in the present
investigation consists of LTCC ceramic composite material layer (ceramic layer) of 20~100*m in
thickness and PET layer of 38 and 75*m in thickness by tape-casting. The diameter of via-holes
ranges from 100~300*m.
Effect of Pb Content on the Fatigue Properties of D.C. Reactive Sputtering-Derived PZT Thin Films
Authors: Yang Dae Jin , Cho Seong Je , Kim Jong Oh , Choi Won Youl
Published: March 2009

Lead zirconate titanate (Pb(Zr0.48Ti0.52)O3 or PZT) films were grown on platinized silicon
wafers (Pt/SiO2/Si) by d.c. reactive sputtering method with multi targets. The Pb content of PZT
films has been widely recognized as affecting not only the phase formation and microstructure but
also the dielectric and ferroelectric properties. Pb content of PZT films was controlled by the
variation of Pb target current. The relation between Pb content and Pb target current was expressed
as y=0.89x-11.09. The x and y are Pb target current and Pb content, respectively. The pyrochlore
phase was transformed to perovskite phase as Pb content was increased. This phase transformation
improved the ferroelectric properties of PZT films. In PZT films with perovskite phase, fatigue
properties were not improved with excess Pb content. Fatigue properties of PZT films began to be
fatigued after 106 switching cycles and coincided with the typical PZT fatigue behavior. Excess Pb
content (Pb vacancy) did not affect the fatigue properties of PZT films.
Identification of Load Applying on T-Shape Joint with Inverse Problem
Authors: Song Joon Hyuk , Kang Hee Yong , Yu Hyo Sun , Yang Sung Mo
Published: March 2009

In the beginning of design, exact load data are actually necessary for the fatigue strength
and life analysis to minimize the cost and time of designing. The procedure of practical load
determination is developed by the combination of the principal stresses of F.E.Analysis and
experiment. This paper conceives new procedure for the determination of load direction and
magnitude applied on mechanical structures. New procedure is the combination of the analytical
and empirical method with analyzed strain by F.E. Analysis under unit load and with measured
principal stress by strain gages under driving load, respectively. In this paper, we theorize the
procedure of practical load determination and make the validity and the practicality of the procedure
with the application to T-shape jointed structure. F.E. Analysis is conducted to get the principal
stress on arbitrary points in the F.E. model of T-shape joint under unit load. Then experiment is
carried out to get the principal stress on the same points of F.E. model. To demonstrate the actual
driving condition, the load conditions are bending and torsion. From these two data sets, the
magnitude, the direction and the position of load can be obtained.
Evaluation of Internal Leak in Valve Using Acoustic Emission Method
Authors: Lee Sang Guk , Park Jong Hyuck , Yoo Keun Bae , Lee Sun Ki , Hong Sung Yull
Published: March 2009

This study is to estimate the feasibility of acoustic emission(AE) method for the internal
leak from the valves. In this study, two types of valve(a 4 inch glove steam valve and 4 inch ball water
valve) leak tests using three different leak path and various leak rates were performed in order to
analyze AE properties when leaks arise in valve seat. As a result of leak test for specimens simulated
valve seat, we conformed that leak sound amplitude increased in proportion to the increase of leak
rate, and leak rates were plotted versus peak acoustic amplitudes recorded within those two narrow
frequency bands on each spectrum plot. The resulting plots of leak rate versus peak AE amplitude
were the primary basis for determining the feasibility of quantifying leak acoustically. The large
amount of data attained also allowed a favorable investigation of the effects of different leak paths,
leak rates, pressure differentials and AE sensors on the AE amplitude spectrum. From the
experimental results, it was suggested that the AE method for monitoring of leak was feasible.
Quantitative Evaluation of Strain Induced Martensite in STS 316L Stainless Steel
Authors: Kim C.S. , Kim Il Ho , Park Ik Keun , Hyun C.Y.
Published: March 2009

In the present work, the strain induced martensite in 316L stainless steel was quantitatively
characterized by X-ray diffraction, the measurement of the magnetic coercivity and the AE technique
during the monotonic tensile deformation of plate specimens. Plate specimens subjected to different
heat treatments (i.e. having different initial microstructures) were tensile-deformed and the AE counts
obtained during tensile deformation were correlated with the microstructural development. The AE
count was observed to increase with increasing amount of strain induced martensite phase, as
determined by X-ray diffraction analysis. The potential of the AE technique and the measurement of
the magnetic coercivity to be used for the evaluation of the tensile deformation was discussed in
relation to the existence of strain-induced martensite.
Nondestructive Evaluation on Thermal Shock Damage of Ceramics
Authors: Lee Jin Kyung , Lee Joon Hyun , Lee Sang Ll
Published: March 2009

The objective of this paper is to investigate the applicability of ultrasonic wave technique
to monitor the progress of the thermal shock damage on alumina ceramic. For this purpose, alumina
ceramic specimen was heated in the furnace and then was quenched into the water tank. The
initiation, growth behaviors of surface micro-cracks as a function of the number of thermal shock
cycle have been discussed by taking into account the change of ultrasonic wave velocity and
attenuation. The change of both velocity and attenuation of ultrasonic wave showed good relation
with the surface crack density changing due to the number of thermal shock cycle. Measuring the
change of attenuation gives more effective information to evaluate thermal shock damage than that
of velocity nondestructively. The flexural strength was also measured for the thermal shocked
specimen. The flexural strength was decreased rapidly at the point of time of observation of microcracks
on the surface of specimen, and the flexural strength decline by the crack growth caused
thermal shock cycles was slight.
Elastic Property Measurement of High-Tension Bolt Based on Mode Converted Ultrasound
Authors: Kim Noh Yu , Lee Sang Soon
Published: March 2009

Elastic properties of high tension bolt are evaluated non-destructively by measuring
acoustic longitudinal and shear wave velocities using mode-converted ultrasound. Mode-converted
longitudinal and shear waves along bolt are captured to calculate acoustic wave velocities and
determine elastic constants such as Young’s modulus and Bulk modulus based on acoustoelasticity.
Ray analysis to select a specific mode conversion from longitudinal mode to shear mode
is carried out and discussed with experimental results. From experiment results of maximum 5% of
measurement error, it is shown that the proposed mode-converted ultrasonic technique is very
effective and sensitive enough to characterize mechanical modulus of high-tension bolts
quantitatively.
Development of a Virtual Model and Experimental Simulator for the Human Cervical Spine
Authors: Ahn Hyung Soo , DiAngelo Denis
Published: March 2009

In this study, we introduced a virtual model and experimental simulator applicable to
kinematics and kinetics analyses of the human cervical spine. The geometry of cervical vertebrae
was created from computer tomography images. The disc joints were modeled as load-based joints
having non-linear viscoelastic properties defined by data from in vitro experiments. The facet joints
were modeled to rotate freely and translate along facet planes. Ligaments were modeled as nonlinear
spring-damper elements. Simulated testing of the virtual model was conducted and the global
stiffness response passed all of the statistical comparison tests. The model provided realistic
visualization of in vitro experimental protocol.
Spatial Variation in Material Properties in Fascicle-Bone Units from Human Patellar Tendon
Authors: Chun Keyoung Jin , Butler D.L.
Published: March 2009

An understanding of the mechanical responses of the patellar tendon (PT) subunits should aid in
determining which portion of the tissue might best be used as a cruciate ligament replacement.
Human cadaveric knees were obtained from young donors. Fascicle groups with patellar and tibial
bone blocks (subunits) were cut to provide six equally-spaced test specimens for each PT. After
potting each bone end in PMMA, specimens were mounted in a saline-filled chamber, preloaded to
0.26 N and then subjected to 40 cycles of preconditioning to 2.5 % of the initial length at a strain
rate of 1.25 %/sec, and then preloaded to 0.26 N again and failed at a strain rate of 100 %/sec using
an Instron. The moduli and maximum stresses were generally greater in the lateral and mid subunits
than in the medial subunits. The strains to maximum stress were similar between the lateral and
medial subunits, but mid subunits had larger strains. Most strain values were distributed between
10 % to 20 %. Mechanical responses of human PT do vary from location to location. In general, the
mid and lateral subunits were stiffer and carried greater stresses than the medial subunits. The
results of this research should eventually be important, e.g. in selecting which portion of the PT
would be the most suitable for cruciate ligament replacements to use as an autograft. On the basis of
strength and stiffness, the more lateral portion of the PT would seem to be more advantageous.
Biomechanical Research on Operations of Hangmann Fracture with Finite Element Method
Authors: Yang Guo Biao , Ding Zhu Quan , Wu Kui , Wang Dong Fang
Published: March 2009

There are increasing incidence of Hangman fracture with the development of society
and industrialization. The research on upper cervical spine concerning hangman fracture is able to
be well carried on with The finite element method(FEM) developing. The research includes a
biomechanical experiment of cadaver specimens and FEM analysis accordingly. The finite element
models of geometrical complex structure from medical images are generated automatically, the
research presents simulation of different surgical option of hangman fracture, testified the models
by loads, calculated the stabilities and stress of models. The corresponding results were summarized
with experiment of cadaver specimens. The research demonstrate that clinical therapeutics is an
good option for Hangman fracture with C2-3 inter-vertebral disc injury.