bluuebunny/crossref_metadata_2025 huggingface dataset:
Distributions of Residual Stresses in Diffusion Bonding of Dissimilar Materials Intermetallics TiAl to Steel 40Cr and Effect of Interlayer
Authors: He Peng , Liu Duo
Published: March 2009

Distributions of residual stress in diffusion bonding of dissimilar materials intermetallics
TiAl to steel 40Cr were simulated by FEM calculation. Results showed that destructive residual
stresses presented in the minute area adjacent to bond-line of the base material with the smaller
thermal expansion coefficient. Reducing bonding temperature and diminishing bonding time are in
favor of the mollification of interface tresses. Concepts of the residual stress factor Rf and the
thickness factor Tf were propounded. As selecting the interlayer, the interlayer with smaller |Rf| and
Tf should be given precedence, and with a prerequisite of sufficient physical contact small thickness
of the interlayer are finer.
An Estimation Formula of the Stress Concentration Factor of the Butt-Welded Joint
Authors: Goo Byeong Choon
Published: March 2009

The purpose of this paper is to develop an estimation formula of stress concentration
factors of butt-welded components under tensile loading. To investigate the influence of weld bead
profiles on stress concentration factors of double V groove butt-welded joints, butt-welded
specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius,
flank angle and bead height were measured by a profile measuring equipment. By using the
measured data, the influence of three parameters on the stress concentration factors was investigated
by a finite element analysis. It is shown that the three parameters have similar effects on the stress
concentration factors. According to the simulation results, a formula to estimate the stress
concentration factors of butt-weld welded structures was proposed and the estimated concentration
factors from the formula were compared with the results obtained by the finite element analysis.
The two results are in a good agreement.
Effect of Properties of Underfill Materials on Thermal Stress Relief in Lead-Free Solder Joint of Chip Size Package
Authors: Shohji Ikuo , Yoshizawa Keisuke , Nishimoto Masaharu , Kawano Takayuki
Published: March 2009

The effect of the mechanical and physical properties of an underfill material on thermal
stress relief in a lead-free chip size package (CSP) solder joint has been investigated. Thin sheets of
underfill materials for the CSP solder joint were prepared and the mechanical and physical
properties of the sheets were investigated. Using these properties, thermal stress relief in an
encapsulated CSP lead-free solder joint with the underfill material was examined by a finite element
analysis method under thermal cycle conditions in the temperature range from 293K to 398K and
233K.
Influence of Content of Ni and Ag on Microstructure and Joint Strength of Lead-Free Solder Joint with Sn-Ag-Cu-Ni-Ge
Authors: Shohji Ikuo , Tsunoda Satoshi , Watanabe Hirohiko , Asai Tatsuhiko
Published: March 2009

An influence of content of Ni and Ag in a Sn-Ag-Cu-Ni-Ge lead-free solder has been
investigated on microstructure and joint strength of the soldered joint under heat exposure
conditions. The growth kinetics of the reaction layer formed at the joint interface has been
investigated, and the apparent activation energy of the reaction layer growth has been also
examined. Moreover, the soldered joints with Sn-Ag and Sn-Ag-Cu solders were prepared and were
compared with the joints with the Sn-Ag-Cu-Ni-Ge solders.
Microstructure and Strength of Alumina-Metal Joint Brazed by Activated Molybdenum–Manganese Method
Authors: Liu Gui Wu , Qiao Guan Jun , Wang Hong Jie , Jin Zhi Hao
Published: March 2009

High purity alumina/stainless steel joints were produced via activated molybdenummanganese
(Mo-Mn) route using 72Ag-28Cu solder. Microstructures of the metallized ceramic and
joint sections were observed by scanning electron microscopy. Joint strength was tested by
shear-loading method. Some process factors were characterized and analyzed, which include
temperature, holding time and heating and cooling rate in ceramic metallization process. The effects
of Ni plating and succedent annealing were also investigated. Experimental results show that,
migration of glassy phases is the main mechanism of the ceramic metallization. Glass migration
direction is from metallizing layer to ceramic side. In the ranges of temperature and holding time of
metallization, joint strength firstly increases and then falls with temperature raising and time
extending. More fully sintered metallizing layer can be obtained while the temperature increases
from 1200oC to 1500oC, and the time prolongs from 30min to 60min. Over-sintering of the
metallizing layer will take place with metallizing temperature of 1600 oC and overlong holding time
of 70min, which reduces the joint strength. The slower heating and cooling rate, and the annealing
after Ni plating both help enhance the seal strength, due to relieving or eliminating interlayer
residual thermal stress. However, too slow heating and cooling rate, such as 5 oC /min, is equivalent
to overlong holding time and finally also decline the strength. A thin Ni coating helps solder wet
metallizing surface, and stops solder erode metallizing layer.
Fatigue Durability Analysis Based on FE Modeling Support System for Arc-Welded Members in Automobile Suspension Module
Authors: Han Seung Ho , Shin So Young , Lee Tae Hee , Lee Sang Boo , Kwon Tae Woo
Published: March 2009

In an early stage of design process for the lower arm in automobile suspension module,
an easy and fast FE modeling, static and durability analysis supported by parametric study
considering its geometric changes are required. The FE modeling support system has been
developed, which is implemented on the platform of MSC.Patran. The CAD file produced by taking
into account of automatic 3D parametric model in CATIA V5 can be transferred to this system. For
the process automation of various design activities including the parametric study, human
interactions are excluded practically, in which all processes are dealt with the XML-wrapper, and
in- and output data are linked each other and treated in the engineering data management. The
developed FE modeling support system reduces time and cost to design and analyze engineering
problems.
Preparation and Characterization of Cr2O3 Nano-Powders by Sol-Gel Method
Authors: Zhu Chun Cheng , Hong Yan , Zhang Jian Guang , Zhou Bai Bin
Published: March 2009

Cr2O3 nano-powders were successfully fabricated with using chromium nitrate and
aqueous ammonia as starting material and urea as dispersant agent by sol-gel method. The
formation of crystalline phase during heat treatment of dry gel was characterized by differential
thermogravimetry (DTG) and X-ray diffraction (XRD) techniques and the temperature of
calcination was determined as 400°C. Scanning electron microscopy (SEM) was utilized to observe
the morphology of the as-fabricated Cr2O3 particles. The results showed that Cr2O3 particles are
spherical or square with little agglomeration and a diameter of about 30 nm. The specific surface
area of Cr2O3 particles was measured as 44.23 m2/g by Brunauer-Emmett-Teller (BET).
Near Full Density Nano Iron-Based Materials by Pulse Current Sintering
Authors: Li Yuan Yuan , Long Yan , Li Xiao Qiang , Ngai Tungwai Leo
Published: March 2009

Constant current plus pulse current electrical sintering was introduced into the sintering
of a ball-milled nanocrystalline Fe-2Cu-2Ni-1Mo-0.8C mixed powder. Effect of pulse current
charging time on the properties of sintered products was studied. Constant electric current sintering
was also used for comparison. A nanostructured iron-based material was obtained within 4 minutes
of sintering. It has a density of 7.7 g/cm3 (relative density of 98.7 %) with an average grain size
(iron-matrix) of 58 nm and carbide particle size of less than 100 nm, a hardness of HRC 64 and
transverse rupture strength of 2004 MPa. When only pulsed electric current sintering was used with
a sintering time of 5 min, a fine grained iron-base material with density of 7.74 g/cm3 (relative
density of 99.2%), a hardness of HRC 65 and transverse rupture strength of 2045 MPa was obtained.
Phenomenological Study of the Size Effect on Martensitic Transformation in Nanograined Powders
Authors: Wang Hong Bin , Wu Xiao Chun
Published: March 2009

On the basis of the Landau-Ginzburg models established by Falk and other authors, a
new model for martensitic transformation in nanograined powder is developed, in which the
influence of the interface on martensitic transformation in nanograined powder is considered. The
interface strain coefficient K, the factor describing the difference of the strain between the interface
and the core of a nano-grain, was suggested in this paper. The equation in the present model was
solved numerically, and the size effect was observed. The calculation results show that the critical
size increases with the drop in temperature, which means that the lower temperature will promote
martensitic transformation in nanograined materials.
Comparison of Property of Dynamic Melting-Loss H13 Steel by Different Surface Treatment
Authors: Chen Yu Hua , Wu Xiao Chun , Min Yong An
Published: March 2009

In order to prolong the service life of Aluminum alloy die casting dies, different surface
treatments were adopted to avoid melting loss on the surface of the dies. In this paper, the dynamic
melting-loss properties of H13 steel were compared among non-treatment, vapor oxidation treating,
carbonitriding and composite treatment of nitirding and vapor oxidation in liquid aluminum of
ADC12 at 700 °C by the weight loss method. The surface structures of the specimens after
treatments were analyzed by the optical microscopy (OP); the patterns of specimens on the surface
were observed by measuring microscope and the melting-loss characteristics of specimens with
different treatment were analyzed. The results showed that the melting-loss property was heightened
obviously by different surface treatments; especially the melting-loss property of the specimens
with composite treatment of nitirding and vapor oxidation was the best.
Effect of pH Values on Conversion of Calcite Crystals into Calcium Phosphate Phases in Buffer Solutions
Authors: Guo Ya Ping , Li Bao Qiang , Zhou Yu , Jia De Chang
Published: March 2009

Calcium phosphate phases with laminar-plate structure were converted from calcite
powders after soaking in phosphate buffer solutions of pH’s 6.0-8.0 at 37 °C for 9 days. The effect of
pH values on the conversion of calcite crystals was investigated by X-ray diffraction, scanning
electron microscopy and Fourier-transform infrared spectroscopy. If the pH value of a buffer solution
is kept at 6.0, calcite powders are converted mainly to dicalcium phosphate dehydrate (DCPD) or
octacalcium phosphate (OCP). If the pH value is kept at 6.4 or 7.0, calcite powders are converted
mainly to OCP. Hydroxyapatite (HAP) with poorly crystalline can be obtained from calcite powders
both by treatment of a basic buffer solution, and by treatment of an acid buffer solution without
regulating its pH value during the reaction. The conversion mechanism of calcite crystals is a
dissolution-precipitation reaction.
Young’s Modulus of Polysilicon Thin Film Evaluated by Finite Element Analysis
Authors: Tanaka Kazuto , Minoshima Kohji , Imoto Takehiro
Published: March 2009

To analyze the effect of the crystal orientations and the grain size on the Young's modulus
of thin polysilicon microelements, two-dimensional finite element models in plain strain condition
were developed using a Voronoi structure. The number of grains in a model of a 10 μm square area
was changed from 23 to 1200. The grain size and the crystal orientation of the film were analyzed by
means of an electron back-scattering diffraction pattern (EBSP) method. The average grain size of the
front surface of the thin film was about 0.69 μm, which is almost equal to the grain size of the Voronoi
model having 300 grains. From the results of EBSP analysis, the specimen had no oriented structure.
Therefore, random crystal orientation was given to each grain of the FEM models. When the number
of grains increased, the Young's modulus converged on about 171 GPa and its scatter caused by the
different sets of the random orientation was reduced. The Young's modulus obtained by the FEM
analysis was larger than the value obtained by the tensile tests.
Stress Corrosion Cracking of Pipeline Steel in Soil Environments of Eastern China
Authors: Li Guang Fu , Huang Chun Bo , Guo Hao , Yang Wu
Published: March 2009

Stress corrosion cracking (SCC) behaviors of pipeline steel X70 in various near-neutral pH
soil environments with characteristics of eastern China have been studied through electrochemical
measurements and slow strain rate tests (SSRT) at various electrode potentials in four solutions
containing different typical soils in eastern China as well as in NS-4 solution. The SCC susceptibility
in the four soil solutions was generally higher than that in NS-4 solution. There was a general trend
that SCC susceptibility increased with decreasing the potential, suggesting that hydrogen induced
cracking probably plays a key role in the cracking at least at low potentials and the parameters of
cathodic protection in engineering should be carefully optimized to avoid SCC.
Mechanical Behavior during Self-Oscillating of NIPAAm-Co-(Ru(bpy)3 Gel
Authors: Aoki Reiko , Enoki Manabu , Yoshida Ryo
Published: March 2009

Self-oscillating gel is designed by copolymerizing the catalyst for the
Belousov-Zhabotinsky (BZ) reaction with thermosensitive polymer. The cylindrical-shaped
specimens of NIPAAm-co-(Ru(bpy)3 gel were prepared by copolymerizing (Ru(bpy)3) monomer as
catalyst with NIPAAm as thermosensitive polymer. Swelling behavior during self-oscillating of gel
by BZ reaction was observed using CCD camera and the force due to this reaction was evaluated
using semiconductor gauge. Self-oscillating swelling-deswelling behavior in samples with different
swelling ratio was evaluated by this apparatus, and mechanical parameters such as Young’s modulus,
stress amplitude and oscillating period were quantitatively estimated.
The Swelling Behavior of Organoclays
Authors: Zeng Qing Hua , Paul Donald R. , Yu Ai Bing , Lu Gao Qing Max
Published: March 2009

Natural clay minerals are ideal nanofillers for polymer materials and have been attracted
tremendous research and development interests in the past decade. The manufacture of clay
nanofillers relies largely on the exfoliation of clay particle into individual clay platelets. Thus,
understanding the interlayer swelling of clay minerals upon the adsorption of surfactants is important
to the fabrication and design of polymer nanocomposites. This paper reports our recent experimental
and theoretical studies on a variety of organoclays that show a linear relationship between the increase
of d-spacing and the mass ratio between organic and clay.
Self-Assembly Effects of Cyclic Peptide Dimers: Molecular Modeling Study
Authors: Zhu Jing Chuan , Cheng Jie , Liu Bo
Published: March 2009

The cyclic peptides can self-assemble into β-sheet like antiparallel tubular ensembles
through intermolecular hydrogen-bonding interaction. Under the self-assembling effects of the
dimer subunits, various aggregate properties may alter with the change of the structure. The
relationship between the property and structure of ensembles is extremely important for designing
new nanostructures. Molecular mechanics (MM) and molecular dynamics (MD) were employed to
investigate the structure and property of single dimer and dimer-ensemble from cyclo-[D-Phe-(1R,
3S)-γ-Acc]3. Results reveal that the single dimer cannot adsorb CHCl3 molecule into its cavity,
while the two-dimer ensemble can do. It suggests that the self-assembled cyclic peptide nanotube
from the dimer-ensemble may act as the transport channel of CHCl3 molecules.
Nondestructive Evaluation of the Corroded Pipe by Time-Frequency Analysis
Authors: Nam Ki Woo , Kim Jin Wook , Ahn Seok Hwan
Published: March 2009

During plant operation, high temperature and high pressure water and steam are flowing
at high velocity inside these piping systems. In pipes of power plants, local wall thinning may result
from erosion/corrosion(E/C). Therefore, it is important to evaluate the nondestructive characteristics
for corroded pipes to maintain the integrity of the secondary piping systems. In this study, the
pressure vessel piping with corrosion used during long terms were investigated from the timefrequency
analysis method. The damage of piping could be evaluated by ultrasonic parameters such
as center frequency and echo waveform. Based on NDE analysis by time-frequency analysis
method, it should also be possible to evaluate from various damages and defects in piping members.
Numerical Analysis of the Measuring Errors in Quantitative Detection of Defects with Shearing Speckle Pattern Interferometry
Authors: Li Xi De , Wang Kai
Published: March 2009

Recently, quantitatively nondestructive testing (QNDT) is becoming an accepted concept
in some industries and scientific research areas. The combination of shearing speckle interferometry
(SSI) and mechanical models is employed to quantitatively estimate defect characteristic parameters
(DCP), such as coordinates, size, embedding depth, etc. However, quantitative calculation of DCP
relies on the actual displacement slope in the mechanical models, but the slope in SSI is represented
by the difference of displacements between the two neighboring points with a distance, i.e. the
shearing amount. This leads to a deviation in calculating DCP. This paper will investigate the
deviation of the relative displacement and derivate displacement introduced by the shearographic
approximation in cases of two deformation models, one is a thin circular plate and the other a
spherical pressure shell under the pressure loading. Two kinds of defects, a cavity and a crack, are
embedded in the structures and their deformations are calculated by FEM.
Damage Identification of Rock Mass with Artificial Neural Networks
Authors: Shangguan Zi Chang , Li Shou Ju , Luan Mao Tian
Published: March 2009

The inverse problem of rock damage detection is formulated as an optimization problem,
which is then solved by using artificial neural networks. Convergence measurements of
displacements at a few of positions are used to determine the location and magnitude of the
damaged rock in the excavation disturbed zones. Unlike the classical optimum methods, ANN is
able to globally converge. However, the most frequently used Back-Propagation neural networks
have a set of problems: dependence on initial parameters, long training time, lack of problemindependent
way to choose appropriate network topology and incomprehensive nature of ANNs. To
identify the location and magnitude of the damaged rock using an artificial neural network is
feasible and a well trained artificial neural network by Levenberg-Marquardt algorithm reveals an
extremely fast convergence and a high degree of accuracy.
Experimental Study on Crack Propagation by AE Location under Uniaxial Compression Condition
Authors: Zhao Xing Dong , Li Yuan Hui , Yuan Rui Fu
Published: March 2009

AE technique is proved a efficient tool for real-time monitoring of the crack initiation and
propagation during rock failure process under uniaxial compression condition. In this paper, An AE
system was employed to investigate the crack propagation and failure modes of three groups of
granite specimens (80mm×100mm×170mm) with the same pre-existing crack. The AE sensors can be
surface mounted. By using a Geiger location algorithm, AE event location can be determined by
time-of-arrival times. The propagation velocities of p-wave or s-wave of granite samples were
measured. Experiments on pre-existing crack propagation of granite samples were carried out on the
press machine. From the testing result, failure mode of three kinds of granite samples was mainly
shear failure, while the secondary crack propagated slowly and could not influence the failure mode of
granite sample. By surveying the relation of accumulative AE events and stress-strain curve, AE
activity represents different characters with stress-strain changing during the total loading process,
microcracking contributing to fracture propagation with strain corrosion. AE location result reflected
crack initiation and propagation, which is of great importance in studying rock instability and
predicting rock failure mode.
Reliability-Based Sensitivity Design of Beam Structure with Non-Normal Distribution
Authors: He Xiang Dong , Zhang Yi Min , Xue Yu Chun , Wen Bang Chun
Published: March 2009

Based on the reliability-based design theory and sensitivity analysis method, the
reliability-based sensitivity design of beam structure with non-normal distribution parameters is
extensively researched and a numerical method for reliability-based sensitivity design is presented.
The variation regularities of reliability sensitivity are obtained and the effects of design parameters
on reliability of beam structure are studied. The method presented in this paper provided the
theoretic basis for the reliability-based design of beam structure with non-normal distribution
parameters.
Experimental Study of the Effects of Surface Defects on Rolling Contact Fatigue Behavior
Authors: Chen Guan , Zhao Hong Ping , Ji Shao Hua , Feng Xi Qiao , Shi Hui Ji
Published: March 2009

Rolling contact fatigue (RCF) cracks initiated from surface and subsurface defects are
typical failure modes of bearing systems. In this paper, the effects of surface defects on RCF
behavior of M50NiL and M50 steels were studied experimentally. Artificial dents were introduced
on the rolling surface by using Rockwell hardness tester. The influences of dent shape and dent
shoulders were examined by thrust-type RCF tests. Surface cracks initiation, propagation and
spalling were monitored by scanning electron microscope (SEM) observation. The results showed
that artificial dents reduce RCF lives of M50NiL and M50 steels with mineral oil lubrication. The
fatigue failure initiates at the surface defect with the effects of dent shape and dent shoulder.
M50NiL steel has higher contact fatigue resistance than M50. The features of surface and
sub-surface cracks propagation during RCF tests were also observed.
The Safety Assessment of Wheelchair Occupants in Road Passenger Vehicles in a Frontal Crash: A Computer Simulation
Authors: Lee Young Shin , Lee Ki Du , Lim Hyun Kyoon
Published: March 2009

With the increasing needs of the more convenient transportation, wheelchairs are often
used by people with mobility disabilities and the elderly people. However, as wheelchairs are
primarily designed for the mobility assistive devices, not for the vehicle seats, wheelchair users are
exposed to risk factors for neck and upper body injury caused by automobile accidents.
In this paper, in accordance with the ANSI/RESNA WC-19, a fixed vehicle mounted wheelchair
occupant restraint system (FWORS), wheelchair integrated restraint system (WIRS), and wheelchair
integrated x-bend restraint system (WIXRS) are evaluated using computer simulations for the case
when a wheelchair is subjected to the frontal impact (20 g, 48 km/h).
Precision Diagnosis of Electric Multiple Units for Performance Evaluation
Authors: Kim Jeong Guk , Park Kyung Taek , Yoon Sung Cheol , Kwon Sung Tae
Published: March 2009

The precision diagnosis of subway electric multiple units (EMUs) was conducted with
various types of engineering analysis techniques for the current performance and wear evaluation.
The evaluation was conducted on detailed parts of EMUs, such as car bodies, bogies, braking
systems, and electrical systems of EMUs. Several characterization means including nondestructive
evaluation techniques, corrosion testing, and three-dimensional measurements, were employed for
the evaluation of car bodies and bogies. For braking system, degradation and performance tests
were conducted, while the functional and degradation tests were performed on electrical system in
order to identify the actual performance of the system. Moreover, stress and structural analyses
using commercial finite element method (FEM) software provided important information on stress
distribution and load transfer mechanisms. In this investigation, various advanced engineering
analysis techniques for the safety analysis of subway EMUs have been introduced and the analysis
results have been used to provide the critical information for the criteria of safety assessment.
Risk Based Approach of In-Service Inspection and Maintenance for Petrochemical Industries
Authors: Choi Song Chun , Lee Jae Hoon , Lee Chang Hun , Song Ki Hun , Chang Yoon Suk , Choi Jae Boong
Published: March 2009

Goal setting safety legislation for high pressure systems was first introduced in 1973 and
retained in the High Pressure Safety Management Law in Korea. This has enabled a move towards
inspection strategies based on the risk of failure. This trend towards a risk based approach is being
supported by extensive plant operating experience, improved understanding of material degradation
mechanisms, and the availability of fitness-for-service assessment procedures. RBI (Risk-Based
Inspection) is very effective and efficient of the inspection and maintenance techniques. In particular,
RBI will be found how to apply both inspection interval as a result of RBI implementation and
re-inspection interval of pressurized equipment defined by the High Pressure Safety Management
Law in Korea. The objectives of this paper are to develop an enhanced KGS-RBITM program to
resolve shortcoming inclusive of the above issue and to evaluate the risks of equipments in Naphtha
Cracking Center (NCC) which is a typical facility of petrochemical plant using the KGS-RBITM
program. The results of the risk assessment and re-inspection interval of internal opening using
KGS-RBITM program are useful in determining the inspection planning.
Crack Problem for a Functionally Graded Orthotropic Coating-Substrate Structure
Authors: Guo Li Cheng , Wu Lin Zhi , Yu Hong Jun
Published: March 2009

The crack problem for a functionally graded orthotropic coating-substrate structure under
an in-plane load is studied. The orthotropic coating is assumed to contain a crack perpendicular to the
interface. Integral transform method is used to obtain singular integral equation. Stress intensity
factors (SIFs) are evaluated. The influences of orthotropic material constants and the geometry
parameters on SIFs are analyzed.
Influence of Non-Gaussian Local Wind Pressures on Fatigue Damage of a Cladding Fastener on a Side Face of a Tall Building
Authors: Ko Nag Ho , Kim Young Moon , You Ki Pyo , Hong Dong Pyo
Published: March 2009

The action of wind pressures is a major consideration in the design of cladding and its
connections to building structures. Non-Gaussian environmental loads often may appropriately be
reduced to Gaussian loads through the central limit theorem, e.g., integral loads on a building under
wind loads. However, for the design load of cladding and its connections to building structures the
Gaussian assumption is not valid and loads remain non-Gaussian, especially in separated flow
regions. When the loads differ significantly from Gaussian distribution, they may lead to increase
expected damage. In this study, the wind-induced high-cycle fatigue damage of a cladding fastener
subjected to non-Gaussian local wind pressures and corresponding simulated Gaussian local wind
pressures is estimated by using the rainflow cycle counting method and Miner’s rule. The fatigue
damage is compared with each other in order to investigate the influence of non-Gaussian local
wind pressures on the fatigue damage of a cladding fastener on the side face of a tall building.
Design Technology of Ω-Shaped Seal Ring Based on Plastic Limit Analysis
Authors: Chen Ye , Gu Bo Qin
Published: March 2009

The nonlinear finite element method (FEM) was applied to the analysis of the strain
distribution in -shaped seal rings acted by internal pressure or the combined action of internal
pressure and axial displacement. The results indicate that the maximum Mises equivalent strain
exists at the juncture between the exterior surface of the loop and that of the knuckle when the ring
is acted by axial compression displacement and relatively large internal pressure, which is in
agreement with the practical work conditions of the rings. According to the plastic limit analysis
method, the limit internal pressure should be determined based on the strained condition of the
juncture between the exterior surface of the loop and that of the knuckle of the ring by using twifold
elastic slope criterion. The formulae for calculating the limit internal pressure of the rings were also
derived by regression analysis of the FEM results. These formulae can be used in the limit design
and the safety assessment of -shaped rings.
The Application of ISDG Method on the Mechanical Property Measurement of the Welding-Line Material
Authors: Xu Fei , Zhu Meng Hui , Tang Zhong Bin , Li Yu Long
Published: March 2009

The mechanical properties of various parts of the welding-line material are different,
while they play very important role in the welding structures, such as the differences of the melted
part and the temperature-affected part. In this paper, a non-contacting laser based technique, ISDG
(Interference Strain Displacement Gauge) method, is applied to find out these property differences
on very small specimen. The testing is very successful and the whole stress-strain curves in such
small scale are obtained on different parts of the welding-line material. The soften phenomena of
the temperature-affected part is observed by the comparison of the Young’s modulus and yield
stress between the melted part and the temperature-affected part.
Effect of Nonlinear Shear Strength Characteristic on the Slope Stability of Super High Rockfill Dam
Authors: Chen Li Hong , Yang Jian , Yuan You Ren , Sun Tao
Published: March 2009

Linear and nonlinear shear strength models of rockfill, and the safety factor criterion of
nonlinear shear strength were discussed in this paper. The slope stability of 261.5 m high Nuozhadu
rockfill dam was analyzed with three different shear strength models. The safety factors are almost
equal and the positions of potential failure surface are similar. It is found that the allowable safety
factor base on linear criterion in the existing code can be used without any change when applying
nonlinear shear strength rules.
On Stress Concentration Character at the Abnormal Cross-Section of the Concentric Shaft with Bigger Diameter Ratio
Authors: Han Zhi Xin , Wang Shao Feng , Du Jin Xia , Liu Bing
Published: March 2009

Aiming at the concentric shaft of the abnormal cross-section where there are two types of
the concave fillet and the convex fillet and whose diameter ratio is bigger than 2, a 3D finite
element computing model was constructed, and the stress and the strain is computed by means of
software ANSYS8.0, and a stress concentration coefficient graph is found through comparing the
result computed by FEM and by the method of material mechanics. It is concluded that the most
important factors effecting the stress concentration are the type and radius of the transition fillet.
The Relation of the Interlaminar Fracture Toughness and the Acoustic Emission (Ae) under the Enf Test
Authors: Kwak Juho , Yun Yu Seong , Kwon Oh Heon
Published: March 2009

Recently, composite materials are used in many fields because their properties are high
strength, high stiffness, and they have light weight, good corrosion resistance and good thermal
conductivity. However, composite materials have relatively a lot of problems, especially
delamination, compared with common materials such as a steel and aluminum, etc. Therefore, having
the interlaminar fracture toughness for a laminate composite is important. In this study, the end
notched flexure (ENF) specimens are employed in order to evaluate modeⅡ interlaminar fracture
toughness for CFRP laminate composites. Three kinds of a/L ratio were applied to these specimens
under the different pressure level. Also, we discuss the relation of crack growth and the interlaminar
fracture toughness in terms of AE characteristics using ENF test.
Quantitative Analysis of Transmission Shafts after Torsion Fatigue Test
Authors: Liu Xin Ling , Zhang Wei Fang , Tao Chun Hu
Published: March 2009

Twelve transmission shafts were developed unilateralism torsion fatigue tests.
Macroscopic and microscopic fracture features of transmission shafts were observed and analyzed.
No defect was found in the origin which was usually located at the bolt bores or nearby the bolt
bores because of the stress concentration. Using the fractography quantitative analysis technology
the propagation life, the origination life and the relation curve between the crack length and the
cycle numbers for all of the twelve shafts were estimated. For only one origin on the fracture
surface the total life of the shaft with two expanding directions is usually obvious longer than that
with one expanding direction, but the main propagation life is obvious smaller. However for two
origins and two expanding directions on the fracture surface the total life of the shaft is usually
shorter.
Static and Fatigue Analysis of a Hybrid Joint Part for the Tilting Car Body
Authors: Jung Dal Woo , Choi Nak Sam
Published: March 2009

Fatigue fracture behavior of a hybrid joint part for the tilting car body was evaluated in
comparison to the case of static fracture. The specimens of hybrid joint part applied in the real
tilting car body were fabricated for the bending test. Characteristic fracture behaviors of hybrid joint
part specimens under cyclic loads were obviously different from the case under static loads. Static
bending load caused the shear deformation and fracture in the honeycomb core region, while cyclic
bending load did the delamination along the interface between composite skin and honeycomb core
layers as well as the fracture of welded joint part. Experimental results obtained by static and
fatigue tests were reflected in modifications of design parameters of the hybrid joint structure in the
real tilting car body.
Thermal Deformation Analysis of Copper Microbridges with Speckle Interferometry and Finite Element
Authors: Zhang Zhao , Li Xi De , Shen Wen
Published: March 2009

In this paper, a speckle microinterferometric system was employed to study the thermal deformation of the Cu microbridges with different dimensions. The deflections of the microbridges caused by the thermal loading were measured with real-time by the speckle microinterferometric system and the surface temperatures of the bridges were recorded using a digital thermometer. The deformation evaluation after microbridges buckling was also recorded with our testing system. Then, the experimental results were compared with the finite element analysis (FEA).
Microstructure and Properties of Environmental-Friendly Sip/4032Al Composites Used for Electronic Packaging
Authors: Xiu Zi Yang , Wu Gaohui , Zhu De Zhi
Published: March 2009

Sip/4032Al composites for electronic packaging applications with high volume fraction
of Si particles were fabricated by squeeze-casting technology. The microstructure observation
showed that the composites were dense and Si particles distributed uniformly, The interfaces and
the existance of the interface reaction were the important factors which affected the properties of the
composites; The linear CTEs of Sip/4032Al composites was between (8.1~12) ×10-6°C-1, and they
were decreased with the increasing content of Si particles as well as annealing treatment. Kerner
model can predict the CTEs of Sip/4032Al composites moderately; the thermal conductivity can
reach 103W/ (m·°C), which was decreased with the increasing contents of Si particles as well as
annealing treatment. The thermal conductivity of composite calculated was larger than tested values.
The composites had excellent mechanical properties and also could be recycled.
A Study on Failure Prediction of Airborne Electronic Equipment
Authors: Li Hong Peng , He Yu Ting , Shi Rong , Zhang Heng Xi , Li Feng
Published: March 2009

The mostly working time of airborne electronic equipment is under preliminary depletion
failure phase, and inspection & maintenance at intervals can’t lower the failure probability. In this
paper, the law of airborne electronic equipment failure is introduced firstly. Then, methods for failure
prediction are summarized and analyzed. Finally, an example for predicting the airborne radar failure
using the Auto-Regressive (AR) and Support Vector Regression (SVR) model is presented. On this
basis, it is possible to achieve the goal that increases the reliability in working phase and establish a
more scientific maintenance system and to assure the safety of airborne electronic equipment.
Torsional Fatigue of 63Sn-37Pb and Sn-0.7Cu Solders
Authors: Bai Ning , Chen Xu , Li Xin
Published: March 2009

A series of torsional fatigue tests were conducted on 63Sn-37Pb and Sn-0.7Cu solders. A
continuous load drop was observed during the test. It was found that the load drop percentage had
little effect on the elastic strain-life curve but strong effect on the plastic strain-life curve. The fatigue
strength coefficient, fatigue strength exponent and fatigue ductility exponent had no great changes
with the load drop. However, fatigue ductility coefficient showed a great difference and was linearly
varying with load drop. A fatigue criterion of Coffin-Manson type was proposed in relation to load
drop. The descending curve of the stress range with cycle was observed to consist of transient, steady
state and tertiary regions. The percentage of load drop corresponding to the turning point from the
steady state to the tertiary region was about 25% for all strain ranges of 63Sn-37Pb, and 30% for all
strain ranges of Sn-0.7Cu. The torsional fatigue lives were correlated with von Mises equivalent strain
amplitudes well. The fatigue behavior of Sn-0.7Cu is better than that of 63Sn-37Pb.
Micro/Nano Film Getters for Vacuum Maintenance of MEMS
Authors: Jin Yu Feng , Tang Hao , Wang Zhen Feng
Published: March 2009

Vacuum packaging is very important for some micro-electro-mechanical systems
(MEMS) devices to perform their basic functions properly and to enhance their reliability by
keeping these devices away from harmful external environment. In order to maintain high vacuum
in a cavity of MEMS devices, residual gases and leaking gases must be eliminated by embedded
getter materials. Micro/Nano film getters absorbing gases inside the tiny cavity of MEMS
packaging were introduced in this paper. The fabrication and characterization of micro/nano getters
for MEMS applications were also presented. Various kinds of patterned getter films were prepared
for different MEMS applications. The activation temperature and sorption capacity of the nonevaporable
getter (NEG[1]) films was investigated. The formation of micro/nano films on the inner
surface of MEMS devices is totally compatible with Si-based MEMS process and illustrates the
applicability of the technique in vacuum maintenance of MEMS devices.
Behavior of Anisotropic Conductive Joints under Hygrothermal Conditions
Authors: Lin Yong Cheng , Chen Xu , Zhang Jun
Published: March 2009

The long-term hygrothermal aging will induce the irreversible damages of epoxy-based
anisotropic conductive film (ACF) joints. In this study, hygrothermal environment tests were used to
accelerate the degradation of ACF joints in Chip-on-Glass (COG) assemblies. The effects of aging on
adhesion strengths were measured by shear mode tests and changes of molecular conformation of
ACF material were analyzed by Fourier Transform Infrared Spectroscopy (FTIR). Also, the fracture
surfaces of ACF joints were investigated by Scanning Electronic Microscope (SEM). The results
show that the ACF adhesion strengths decrease with aging; some chemical modifications occur in the
aged ACF joints; the fracture failure mechanisms change with the hygrothermal aging.
Threshold Current Density of Electromigration Damage in Angled Polycrystalline Line
Authors: Sasagawa K. , Yamaji N. , Fukushi S.
Published: March 2009

As silicon ICs continue to scale down, several reliability issues have emerged.
Electromigration- the transportation of metallic atoms by the electron wind- has been recognized as
one of the key damage mechanisms in metallic interconnects. It is known that there is a threshold
current density of electromigration damage in via-connected lines. The evaluation of the threshold
current density is a matter of the great interest from the viewpoint of IC reliability. In this study, Al
polycrystalline lines with two-dimensional shape, i.e. angled lines are experimentally treated for the
evaluation. Comparing the experimental result with that of straight-shaped line, the effect of
line-shape on the threshold current density of electromigration damage is discussed.
Finite Element Analysis of Dongjusi Railway Tunnel within Hard Rock Mass Based on the Unified Rock Mass Strength Criterion
Authors: Hua Yuan , Zhou Tai Quan , Dai Guo Liang
Published: March 2009

The twin shear strength criterion has been proposed to consider the intermediate principal
stress effect on the rock mass strength. The unified rock mass strength criterion could consider the
intermediate principal stress effect on the rock mass strength. The unified rock mass elasto-plastic
material model is implemented in ABAQUS user interface. As a case for study, the stability
analysis of Dongjusi railway tunnel within hard rock mass is studied using the unified rock mass
strength material. For comparison, the Hoek-Brown empirical strength criterion is also chosen for
the rock mass material modeling. The computation results show that the plastic zone calculated
using the unified rock mass strength criterion is smaller than that using the Hoek-Brown empirical
strength criterion. The railway tunnel lining structure is designed according to the unified rock mass
strength criterion and greatly makes use of the rock mass potential strength, which decreases
engineering cost.
Life Evaluation of a Disk Brake of Railway Vehicles Considering Pressure Distributions at a Frictional Surface
Authors: Cho Sung Keun , Choi Jung Hun , Lee Young Min , Seok Chang Sung
Published: March 2009

In this study, we performed thermal stress analyses on a ventilated disk brake with a 3D
model for two cases (whether the pressure distribution on a contact surface is uniform or not). A
pressure distribution analysis was performed to determine the pressure distribution on the contact
surface. Then, by using the results that were obtained from the pressure distribution analyses, we
performed thermal stress analyses. Finally, we have found the spots where the maximum thermal
stresses occur. Also, for the life evaluation of a disk brake, we have conducted the fatigue test and
obtained the S-N curve. From those results, we evaluated the life of a disk brake.
Investigation on Purification and Degassing of TiB2/Al Composite Fabricated by LSM Method
Authors: Gu Hong , Zou Yong Zhi , Xu Zheng Bin , Zeng Jian Min
Published: March 2009

In the present paper, TiB2/Al composite with 5% volume fraction of TiB2 was fabricated by
LSM method. The effects of purification and degassing methods on TiB2/Al composite were
examined by means of X-ray diffraction (XRD) and image analysis. Hydrogen contents in the molten
composites were detected and compared among flux, inert gas and vacuum purification processes.
The experimental results indicate that under general cast condition a majority of the TiB2 particles
distribute on grain boundary, and only a few particles disperse within grains. The flux and vacuum
purifications have no virtual impact on the distribution of TiB2 and the fraction of TiB2 remains the
same after purification. However, degassing with inert gas will be detrimental; the TiB2 particles will
be separated and removed from the matrix. The hydrogen contents for flux, inert gas and vacuum
processes are 0.15ml/100g/Al, 0.12ml/100g/Al and 0.12ml/100g/Al respectively.
Influence of the Thickness and Frequency in the Infrared Hybrid Method in Consideration of Heat Conduction
Authors: Machida Kenji , Miyagawa Shohei
Published: March 2009

Recently, the influence of heat conduction has been considered to be a big problem. Then,
the influence of heat conduction was investigated by the experiment which changed the material,
thickness of the specimen and frequency of a cyclic load. Then, the infrared hybrid method was
developed to separate individual stress components. However, it has the influence by heat
conduction in the infrared stress measuring method. Therefore, an error will arise in the infrared
hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed.
Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy
of hybrid method considering to heat conduction was discussed in comparison with the 3-D
finite-element analysis and 2-D hybrid method.
Grain Refinement and Eutectic Solidification Mechanism of Al-Si Hypoeutectic Alloy in Centrifugal Casting with Electromagnetic Field
Authors: Zhang Zhi Qing , Li Qiu Lin , Liu Wei , Liu Qing
Published: March 2009

A series of Al-Si hypoeutectic alloy ingots were prepared by centrifugal casting (CC)
both with and without an external electromagnetic field (EMF). The effects the EMF on grain
refinement and on the solidification mechanism during centrifugal casting have been investigated
using optical microscopy, scanning electron microscopy (SEM) and electron backscattering
diffraction (EBSD) orientation measurements. The electromagnetic stirring effect caused by the
EMF promotes the columnar-equiaxed transition (CET) resulting in a finer cast grain size. The
silicon and aluminum nucleate and grow independently both with and without EMF
Study on the Effect of Cl- Concentration on the Corrosion Fatigue Damage in a Rolled AZ31B Magnesium Alloy by Acoustic Emission
Authors: Zhou Hua Mao , Wang Jian Qiu , Zang Qi Shan , Han En-Hou
Published: March 2009

The fatigue performance of one widely used wrought magnesium alloy AZ31B in rolled
form was studied using acoustic emission (AE). AE energy release during corrosion fatigue (CF)
testing was measured at room temperature. It is found that AE energy release can express corrosion
fatigue damage experienced by the material.
Influence of Residual Stresses on the Interfacial Toughness Measurement by Cross-Sectional Nanoindentation
Authors: Nie Pu Lin , Shen Yao , Yang Jie , Chen Qiu Long , Cai Xun
Published: March 2009

Cross-sectional nanoindentation (CSN) is a new method for measuring interface adhesion
of thin films. The interfacial energy release rate (G), characterizing interfacial adhesion, is
calculated from the material and geometrical parameters relevant to the test. Effects of residual
stresses on G and crack tip phase angle Ψ, have been studied by finite element simulation in this
study. The results show tensile residual stresses increase G and compressive stresses reduce it, and
they have similar effects on the magnitude of Ψ.
Creep Behavior of Functionally Graded Material under In-Plane Bending Moment
Authors: Chen Jian Jun , Xuan Fu Zhen , Wang Zheng Dong , Tu Shan Tung
Published: March 2009

The creep behavior of functionally graded material under in-plane bending moment is
investigated in this paper. By extending the classic beam theory an analytical model is proposed to
predict the distributions of creep strain and creep stress inside the functionally graded material
according to the relationship between the inclusion volume fraction and composite creep coefficient.
The analytical solution agrees well with the results obtained by the finite element method and the
basic knowledge about time-dependent behavior of functionally graded material is achieved to guide
its design and fabrication.