bluuebunny/crossref_metadata_2025 huggingface dataset:
A Method to Determine the Periodic Solution Based on Observed State Information and Nonlinear Analysis of Hydrodynamic Bearing-Rotor System
Authors: Lu Yan Jun , Zhang Yong Fang , Fang Ying Wu , Liu Heng
Published: March 2009

In this paper, a numerical method is presented to determine the periodic response of
hydrodynamic bearing-rotor system. The observed state information of the system is used to solve
inversely the Jacobian matrix, and to trace the periodic response with the change of the control
parameter. Jacobian matrix obtained is used to calculate the Floquet multiplier, so the stability of the
periodic response can be determined by Floquet theory. The proposed method is applied to a rotor
system with the elliptical bearing supports to solve the periodic response and determine its nonlinear
stability. Validity of this method is illustrated by comparing numerical results with the traditional
method.
Correction on Parameters in Torsion Vibration Model for Turbine-Generator Shafts
Authors: Gu Yu Jiong , Li Xiao Bo , He Cheng Bing
Published: March 2009

The accuracy of parameters in model has important influence on torsion vibration analysis
of turbo-generator shafts. In this paper, a method for torsion vibration response calculation based on
multistage lumped mass model is introduced. A method for identification and correction on stiffness
and damping in torsion vibration monitoring is put forward. Pre-revision on shaft stiffness is realized
through analytic calculation of the temperature distribution of turbine-generator shafts. The difference
of natural frequencies and response of torsion vibration of shafts are calculated and analyzed after
parameter correction, which offers the reference for studying torsion vibration fatigue of shafts.
One Method of System Analysis Based on Some Parameters in the Underground Chambers and Application
Authors: Li Xiao Jing , Zhu Wei Shen , Yang Wei Min
Published: March 2009

Based on the underground structure scheme of Langyashan hydro-electrical project, lots
of elastic-plastic numerical analysis were conducted considering modulus of deformation, layout
depth of underground opening, height of main factory premises, coefficient of lateral compressive
stress, as the mainly mechanical parameters that influenced the stability analysis of underground
openings. The mathematical statistics method was employed to investigate the displacement
variation law of key point surrounding house periphery and found the forecast model. Then the
forecast model was used to analyze the sensitivity parameters. It was shown that there was a good
agreement between theoretic result and monitoring result in situ.
Reliability Analysis for Rotor-Stator Systems with Rubbing
Authors: Li He , Zhang Yi Min , Liu Qiao Ling , Ren Zhao Hui , Wen Bang Chun
Published: March 2009

On the basis of the dynamic equations of the Jeffcott rotor-stator model with imbalance,
the reliability of the rotor-stator systems with rubbing is examined. A statistical fourth moment
method is developed to determine the first four moments of system response and state function. The
distribution function of the system state function is approximately determined by the standard
normal distribution functions using the Edgeworth series technique. The reliability is obtained and
the effect on reliability of shaft stiffness and damping, stator stiffness and damping, radial clearance
and stator radial stiffness is studied. Numerical results are also presented and discussed.
Experimental Study on Cracking and Integrity Stability of Xiluodu Arch Dam
Authors: Wang R.K. , Lin P. , Zhou W.Y.
Published: March 2009

In this paper, by employing a three dimensional geomechanics model test whose scale is
1:250, the dam cracking process was observed, and integrity stability was analyzed and evaluated
under overloading test. The experimental results show that: the stress and strain of the dam can
basically meet the requirements of dam safety under normal water load, and the dam failure mode of
the left abutment is different from that in the right side because of different types of dam figure and
geological conditions. Firstly, the local slip fracture is formed on the foundation, then extends along
the bottom of dam, and leads to instability and final failure. In overloading process, crack initiate from
dam heel under twice normal water pressure, and form a small cracking zone, then yielding
continuously and crack band appearing in downstream surface under 4.5th normal water pressure, and
overall failure under 8.5th normal water pressure. The integrity stability is shown strong enough with
experimental dam shape (XLD03 Figure) and the configuration of its foundation.
A Study on the Static Buckling Load Estimation of the Spacer Grid in the Pressurized Water Reactor Fuel Assembly
Authors: Jeon Sang Youn , Kim Kyu Tae , Lee Young Shin
Published: March 2009

This study contains several estimation methods of the static buckling load for the spacer
grid of nuclear fuel assembly in pressurized water reactor. Three different estimation methods were
proposed for the calculation of the static buckling loads of spacer grid. The linear and non-linear
static buckling analyses were performed to estimate the static buckling load of the spacer grids
using ANSYS program. The analyses results were compared with the static buckling test results.
Based on the analysis and test results, the applicability of the proposed estimation method for the
static buckling load of the spacer grid was investigated.
Fault Diagnosis Expert System Integrated Developing Environment Based on CLIPS
Authors: Tan Da Peng , Li Pei Yu , Pan Xiao Hong , Ye Rui Zhi
Published: March 2009

Establishment of a reasonable expert system integrated developing environment (ES-IDE) is a critical factor for developing ES promptly and effectively. By current investigation and analysis of related technology, a kind of IDE for fault diagnosis expert system (FDES) on the base of Protégé+CLIPS+Eclipse tool-chain was brought forward. The model of FDES was realized by Protégé and described by ontological analysis method. Combined with CLIPS, inference engine and knowledge base (KB) were realized and applied to diagnose and deduce, the developing period of ES core framework was shortened, and flexibility of system was increased. Based on component principle, every system module was encapsulated in form of Eclipse plug-in, so users can reconstruct and reconfigure to compile and make ES application instance uniformly according to their specific demands. Industry experiments prove that this system can generate FDES in a shorter period, has strong transplanting ability and friendly human-computer interface.
Creep Life Prediction of Waspaloy Using the Initial Strain Parameter Technique
Authors: Kim Seon Jin , Kong Yu Sik , Jung Won Taek , Yeom Jong Taek , Park Nho Kwang
Published: March 2009

The purpose of this study is to investigate the high temperature creep life of Waspaloy
using the Initial Strain Parameter Technique (ISPT). The creep tests were performed at the elevated
temperatures from 550oC to 700 oC. Constant stress creep tests were carried out in the experiment.
The initial strain was measured for one minute after loading. The creep life of Waspaloy was
calculated using the creep life prediction equation of ISPT. The confidence level between the
experimental rupture time and the calculated rupture time using the ISPT is within 95%. So, the
results show that the creep life prediction by the ISPT was a good agreement with LMP method.
Influence of Plasma Radical Nitriding on Fatigue Properties of SCM435 Steel
Authors: Yan Nu , Lee I. , Murakami Riichi , Yonekura Daisuke , Sun J. , Fukui Satoshi
Published: March 2009

The effect of plasma radical nitriding treatment on fatigue properties of SCM435 steel in
super long life region was investigated. Fatigue tests were carried out using a dual-spindle rotating
bending fatigue-testing machine at room temperature in air for the specimens nitrided at 773 K and
823 K for 3 hrs. The fatigue strength of nitrided specimen was greater than that of un-nitrided
specimen and the crack initiation mode changed from the surface cracking of un-nitrided specimen
to the subsurface cracking of nitrided specimen. Hardening layer and compressive residual stress
were formed by nitriding, which resulted in the improvement of the fatigue strength. The stress
intensity factor was calculated using facet area in Fish-eye fracture mode. As a result, the stress
intensity factor indicated almost constant value, ~ 3-4 MPa·m1/2, regardless of the number of cycles
to failure.
Stress Analysis of Automotive Engine Cover under Static and Vibration Load
Authors: Kim Beom Keun , Kim Heung Seob , Jeong Jae Kwan , Kang Ki Weon , Cho Gyu Chul
Published: March 2009

Structural analysis of automotive engine cover under vibration excitation is performed by
finite element analysis (FEA) in order to identify the critical area of the structure. Assembly load due
to the tightening of the bolts as well as the vibration excitation were considered to describe the actual
loading condition. Natural frequencies of the system were extracted considering the damping effect of
the structure. Dynamic analysis was performed based on the extracted natural frequency of the system.
Experimental modal analysis (EMA) and measurement of strains were performed to verify the results
of the analysis. Analysis results correlated closely with the experimental results. Analysis and
experiments showed that contribution of the assembly load should not be ignored to predict the
structural failure of the engine cover.
Numerical Simulation of Deformation and Strength of Reinforced Concrete Slabs under Thermal-Mechanical Loads
Authors: Sun Xiu Shan , Liu Ying Hua , Cen Zhang Zhi , Fang Dong Ping
Published: March 2009

In this paper, full-scale reinforced concrete slabs are analyzed under thermal-mechanical
loads in fire conditions. The rectangular one-way slabs including a simply supported slab and a
three-span continuous slab are concerned in the analysis. Finite element simulation is carried out by
using the ABAQUS program to evaluate the non-uniform temperature distributions in thickness of
the slabs and to analyze the deformation and stress redistribution of the slabs at elevated
temperatures. Sequentially coupled thermal and structural analyses are performed to simulate the
responses of the slabs in fire conditions. Deformation and strength of the slabs under thermal and
mechanical loads are discussed. The numerical results are compared with the experimental ones and
good agreements are observed. The analysis results show that the main reinforcement ratio has
significant effects on the deformation and strength of the slabs at elevated temperatures and the
three-span continuous slab has better performance of fire-resistance than the simply supported slab.
An Integrated Neural Classifier for Stream Turbine Damage Identification Based on PSO
Authors: Su Hong Sheng , Zhang You Peng
Published: March 2009

To improve the accuracy and overcome the flaws of single neural network, an integrated
neural classifier for stream turbine vibration fault identification is proposed based on particle swarm
optimization (PSO) in the paper. The method firstly establishes diagnosis decision table of stream
turbines from fault sources to fault symptoms based on wavelet package decomposition technique to
faults wave-shape. Then the discrete decision table is acquired by quantifying attribute values in
decision table using information entropy, a simplified decision table then is generated by rough set
reduction. Based on it, several neural networks are applied to identify steam turbine faults at the same
time, and their results are integrated with PSO-based. Both simulation and trial in stream turbine
damage identification indicate that the proposed method has higher identification rate and shorter
training time as well as excellent generalized ability, and is an ideal pattern classifier.
Development of 3-Axis Load Cell for Measuring the Side-Force of the Rear Damper of MPV
Authors: Park Jun Hyub , Chu Sung Il , Choi Hyeon Chang
Published: March 2009

This paper represents the development of 3-axises loadcell for measuring the side-force of
the suspension module of MPV (Multi Purposed Vehicle). The side force causes the failure of damper,
such as leakage. The loadcell was developed using strain gauges, and the Wheastone bridge circuit to
compensate for the cross-talk between each axises and the measurement error by temperature.
Structure analysis of loadcell was accomplished with FEM (Finite Element Method) to optimize the
location of strain gages. The design optimization for the important factors that have effects on
performance of loadcell was accomplished by using DOE (Design of Experiment). Loadcell was
produced and successfully tested, showing good sensitivity and low cross-talk. The cross-talk of the
developed loadcell is below 2%. The measured history using the manufactured load cell will be
utilized in the vibration, and fatigue analysis in the future.
Fatigue Lives of a Ferritic Stainless Steel Containing Deformation Twins
Authors: Taniguchi T. , Kaneko Yoshihisa , Hashimoto Satoshi
Published: March 2009

The fatigue properties of ferritic stainless steel containing deformation twins were
investigated. Monotonic tensile tests and push-pull fatigue tests were conducted on the specimens
both with and without twins. Fatigue lives of the twinned specimens were about four times shorter
than those without the deformation twins, although yield stresses of both specimens were almost
equal. It was found that the fatigue cracking along the deformation twin boundaries caused the
reduction in fatigue life. Dislocation structure observation using the ECCI method revealed that no
specific dislocation structure was formed near the cracked deformation twin boundary, although the
ladder-like PSB structure was developed along an annealing twin boundary in an austenitic stainless
steel.
Optimum Design of a Planar Micromanipulator Using Displacement Amplifier
Authors: Han Seok Young , Yoon S.J. , Kim S.R. , Park J.Y. , Yi Byung Ju , Kim S.J.
Published: March 2009

Sufficient workspace and high natural frequency of a micromanipulator are the
fundamental requirements in its design. In this study, a previous design was analyzed from the
viewpoint of the axiomatic design. Then, a new design parameter as displacement amplifier which
transforms a coupled design into a decoupled design, was suggested. And a design procedure based
on axiomatic design was developed. A planar 3-DOF parallel-type micromanipulator was chosen as
an exemplary device. According to the suggested design procedure, the micromanipulator having
the required natural frequency was designed in the first step, and then the displacement amplifier
satisfying the required work space was designed sequentially. To check the effectiveness of the
manipulator and displacement amplifier, simulations and experiments were performed. Those are
verified that the displacement amplifiers implemened work very well for satisfying the required task
workspace.
A Comparative Study of the Solder Joint Reliability in Flip Chip Assemblies with Compliant and Rigid Substrates
Authors: Lin Yong Cheng , Chen Xu , Liu Xing Shen , Lu Guo Quan
Published: March 2009

The reliability of solder joints in flip chip assemblies with both compliant (flex) and rigid
(PCB) substrates was studied by accelerated temperature cycling tests and finite element modeling
(FEM). In-process electrical resistance measurements and nondestructive evaluations were conducted
to monitor solder joint failure behavior, hence the fatigue failure life. Meanwhile, the predicted
fatigue failure life of solder joints was obtained by Darveaux’s crack initiation and growth models. It
can be concluded that the solder joints in flip chip on flex assembly (FCOF) have longer fatigue life
than those in flip chip on rigid board assembly (FCOB); the maximum von Mises stress/strain and the
maximum shear stress/strain of FCOB solder joints are much higher than those of FCOF solder joints;
the thermal strain and stress in solder joints is reduced by flex buckling or bending and flex substrate
could dissipate energy that otherwise would be absorbed by solder joint. Therefore, the substrate
flexibility has a great effect on solder joint reliability and the reliability improvement was attributed to
flex buckling or bending during temperature cycling.
Interface Cracking of Plastic Electronic Package under Temperature and Humidity Environment
Authors: Chen Xu , Zhao Shu Feng , Zhai Linda
Published: March 2009

Structural model of plastic electronic package under temperature and humidity is
constructed, and the coupling of the thermal and moisture impact on structure field is implemented.
The impact of thermal expansion, hygro-swelling and vapor pressure increases with increasing initial
defect, especially the impact of vapor pressure. At certain crack length, KI and KII induced by thermal
expansion is proportional to temperature difference, and KI and KII induced by vapor is proportional to
vapor pressure. The impacts of thermal expansion and hygro-swelling on ERR decrease during crack
propagation, but the impact of vapor pressure increases significantly.
Fluctuation Mechanism of Mechanical Properties of Electroplated-Copper Thin Films Used for Three Dimensional Electronic Modules
Authors: Miura Hideo , Sakutani Kazuhiko , Tamakawa Kinji
Published: March 2009

The mechanical properties of copper thin films deposited by sputtering and electroplating
were compared using tensile test and nano-indentation. Both the Young’s modulus and tensile
strength of the films were found to vary drastically depending on the microstructure of the
deposited films. The Young’s modulus of the sputtered film was almost same as that of bulk
material. However, the Young’s modulus of the electroplated thin film was about a fourth of that of
bulk material. The micro structure of the electroplated film was polycrystalline and a columnar
structure with a diameter of a few hundred-micron. The strength of the grain boundaries of the
columnar grains seemed to be rather week. In addition, there was a sharp distribution of Young’s
modulus along the thickness direction of the film. Though the modulus near the surface of the film
was close to that of bulk material, it decreased drastically to about a fourth within the depth of about
1 micron. There was also a plane distribution of Young’s modulus near the surface of the film.
Fractal Characterization of Sealing Surface Topography and Leakage Model of Metallic Gaskets
Authors: Feng Xiu , Gu Bo Qin
Published: March 2009

In this paper, the fractal characterization of the sealing surface topography of metallic
gaskets was studied. The influence of the compressive stress on the fractal parameters was also
investigated. It’s found that the sealing surface of metallic gaskets is fractal, and its topography can
be characterized by the fractal dimension and the scale coefficient. The leakage model of metallic
gaskets was established. The research results indicate that the larger the fractal dimension is, and
the less the scale coefficient and the non-contact area are, the better the sealing performance of
metallic gaskets is.
Research on the Non-Contact Manipulation of Biomaterials in the Stationary Sound Field of Ultrasonic Transducers
Authors: Fan Zong Wei , Yang Keji , Chen Zi Chen
Published: March 2009

For applying acoustic radiation force to manipulate biomaterials such as cell, DNA,
bio-macromolecule without contact, stationary sound field of an ultrasonic transducer was computed
numerically. With the numerical data about the sound field, spatial distribution of the acoustic
radiation force was analyzed. Besides the radiation force in the axial direction, trapping forces in the
lateral direction were discovered. By moving the reflector continuously and carefully, positions of
trapping wells were changed simultaneously, as the result, non-contact manipulation of micro cells
was implemented.
Steel Water Continuous Casting Slag Detection System Based on Wavelet
Authors: Li Pei Yu , Tan Da Peng , Pan Xiao Hong , Lin Bo Yu
Published: March 2009

Based on a large number of investigation and analysis for slag detection system (SDS), a
kind of automatic SDS using vibration measurements had been put forward in this paper. After
studying casting process from ladle to pouring box and protection casting supporting mechanical
structure, vibration dynamics model of supporting structure was established, also variation of steel
water impact force and influencing factors of inspecting spot vibration are analyzed. Theories of
wavelet, wavelet package and their applications in signal processing are presented. Vibration signal of
steel water was processed by the way of wavelet package, then its eigenvector and tolerance range
were obtained, and that can realize effective identification for steel water status. Experimental results
indicate that this system is very effective and achieves anticipated outcomes.
Research on Mechanism of Stabilized Soil Mechanics Enhanced by Con-Aid Liquid Stabilizer
Authors: Zhang Xin Gui , Ma Guo Wei , Khoon T.Y. , Yi N.P. , Wu H.
Published: March 2009

The stabilized soil is a reinforcement material being applied extensively to civil
engineering and hydraulic engineering. At present, chemical methods are used to improve density and
strength of soil by increasing the state of inter-particles’ contacts and forces among particles or
particle groups. Liquid stabilizer is the chemical reinforcing agent of stabilized soil. The physical and
chemical interaction of reinforcing agent - clay - water affects the reinforcement of soil. The
mechanism of strengthening soil using the Liquid stabilizer had not been clear. In laboratory, many
experiments were carried out in order to study strengthening mechanism of the stabilized soil. From
the result of the test and analysis of its characteristics, we recognized that the reinforcement effect of
the liquid stabilizer is controlled by the mini-structure of the stabilized soil, and strength of the
stabilized soil comes mainly from its mini-structure.
Free-Edge Stress Singularity of Bonded Dissimilar Materials with an Interlayer
Authors: Ioka Seiji , Masuda Keiji , Kubo Shiro
Published: March 2009

Free-edge stress singularity usually prevails at the edge of the interface of the bonded
dissimilar materials. When two materials are bonded by using an adhesive, an interlayer develops
between two materials. An interlayer may inserted between two materials to defuse the residual
stress due to the difference in the coefficients of thermal expansion.
In this study, to investigate the effect of the interlayer on the free-edge stress singularity of the
bonded dissimilar materials with an interlayer, the stress distributions on the interface were
examined numerically and theoretically. Relation between the free-edge stress singularity of the
bonded dissimilar materials with and without an interlayer was investigated by using the boundary
element method. It was found that the effect of the interlayer on the stress distribution was limited
within a small area of the order of the interlayer thickness. Stress distributions near the edge of the
interface were controlled by the free-edge stress singularity of the bonded dissimilar materials
without an interlayer.
An Analysis of the Fatigue Strength of Metals Containing Small Defects
Authors: Endo Masahiro , McEvily A.J.
Published: March 2009

A modified linear-elastic fracture mechanics approach proposed by McEvily has been
applied to predict the effects of small defects on the fatigue limit and the threshold level. In the
analysis, three modifications were taken into account (1) the effect of elastic-plastic behavior of
small cracks, (2) the Kitagawa effect where in the very small crack regime the required stress for
propagation is controlled by the fatigue limit of a smooth specimen rather than by the long-crack
threshold condition, and (3) the effect of crack closure development from zero up to the
macroscopic level as a newly formed crack extends. Three steels, a brass and an Al alloy were
investigated. Good agreement between predicted and experimental results has been obtained and a
rational basis for the area parameter model was shown.
Effect of Fusing Treatment on Fatigue Strength of Thermally Sprayed Steels with Co-Based Self-Fluxing Alloy Coating
Authors: Oh Jeong Seok , Komotori Jun , Song Jung Il , Kim Tae Gyu
Published: March 2009

Rotational bending fatigue tests were carried out on a medium carbon steel with a thermally
sprayed Co-based alloy coating. The effect of two different fusing treatments on the fatigue strength
of fused specimens was investigated. Fusing treatment was performed using a vacuum furnace, and an
induction heating system. When the specimens were treated in vacuum furnace at 1373 K for 4 h, the
diffusion layer providing a strong adhesive force were formed at the interface between the coating and
substrate. As a result, fatigue strength remarkably increased in comparison with the uncoated
specimens. On the contrary, for the treated specimens with an induction heating system at 1373 K for
120 s, since these specimens had a lower adhesive force due to no formation of diffusion layer,
leading to delamination of the entire coating.
Bending Strength of Al2O3 Ceramics for Textiles Machinery and Elastic Wave Characteristics by Wavelet Analysis
Authors: Nam Ki Woo , Ahn B.G. , Kim M.K. , Son C.S. , Kim Jin Wook , Ahn Seok Hwan
Published: March 2009

The optimized conditions of pressureless sintering were investigated in order to obtain
the bending strength and the elastic wave signal of Al2O3 composite ceramics for textiles
machinery. As sintering conditions, a temperature range from 1400°C to 1700°C and time from 30
minutes to 150 minutes were applied. Three-point bending tests were conducted on the sintered
materials to obtain the strength property. From the test results, the optimum sintering condition was
1600°C, 100 minutes. Al2O3 composite ceramics showed that the elastic wave signal characteristics
had a regular correlativity between the optimum sintering temperature and time as well as the
maximum bending strength.
Dynamic Analysis of Antiplane Crack under SH-Waves in the Functionally Graded Materials
Authors: Li Xin Gang , Jin Cheng , Zhang Li , Chu Da Yong
Published: March 2009

In this paper, the behavior of a finite crack in an infinite plate of functionally graded
materials (FGM) with free boundary subjected to SH-waves is considered. To make the analysis
tractable, it is assumed that the material properties vary exponentially with the thickness direction
and the problem is transformed into a dual integrated equation with the method of integral
transform. The dynamic stress intensity factor is obtained using Schmidt method. The numerical
examples are presented to demonstrate this numerical technique for SH-waves propagating in FGM
plate. Finally the number of the waves, the gradient parameter of FGM and the angle of the
incidence upon the dynamic stress intensity factor are also given.
Effects of Chemical Compositions of the Submerged Arc Welding Wires on Impact Toughness of the Weld Metals for the Pipeline Steel
Authors: Ren De Liang , Xiao Fu Ren , Tian P. , Wang X. , Zhang L.Y. , Liao Bo
Published: March 2009

With the development of high toughness pipeline, it is necessary to develop new welding
wires for high-efficiency submerged-arc welding, to produce weld metals whose properties can
match corresponding ones of the base metal, such as strength, toughness, H2S corrosion resistance,
etc. In this paper, the weld wires with variations of elements have been designed, and the effects of
alloy elements on the microstructures and low temperature impact toughness are discussed.
Strength and Toughness of 1.1wt% Li-Containing Al-Zn-Mg-Cu Alloys
Authors: Zhao Zhong Kui , Zhou Tie Tao , Liu Pei Ying , Chen Chang Qi
Published: March 2009

The effect of ageing processes on the toughness and the yield strength of the
Li-containing Al-Zn-Mg-Cu alloys (Al-5.6%Zn-1.9%Mg-1.6%Cu-1.1%Li-0.24Cr) was investigated.
The microstructure was observed by transmission electron microscopy, tensile test was performed
at a rate of 1mm·s-1, fracture toughness was experimentally determined by the impact test, and the
fracture modes had been assessed by image analysis of scanning electron microscopy micrographs.
The strength of the Li-containing Al-Zn-Mg-Cu alloys treated at 120 °C is not more than 430MPa,
which is very lower than that of 7075 alloys. The strength is comparable to that of 7075–T6 alloys
after double-ageing or multi-ageing, however its ductility is lower than that of 7075-T6 alloys. The
single-aged Li-containing alloys have high toughness. The multi-aged alloys become brittle. The
fracture surface for the Li-containing Al-Zn-Mg-Cu alloys is intergranular, since the intergranular
precipitation weakness the grain boundaries.
Evaluation of Critical Fracture Stress in Low Alloy Steels by Finite Element Analysis of Small Punch Test
Authors: Kim Min Chul , Lee Jae Bong , Oh Yong Jun , Lee Bong Sang
Published: March 2009

The critical fracture stresses (σ*
f(sp)) in various low alloy steels for a reactor pressure
vessel(RPV) were evaluated by a small punch test (SP test) and a finite element analysis (FEA) in
the cleavage temperature region(-150~-196 °C). The load-displacement curves and distances from
the center to the fracture surface (Df) of the FEA results are in good agreement with the
experimental results. The maximum principal stresses (SP fracture stresses, σf(SP)) were determined
from the FE analysis, when the maximum load was applied to the SP test. The SP critical fracture
stress, σ*
f(sp) in various reactor pressure vessel (RPV) steels was found to have a linear relationship
with the values obtained from the precracked specimens (σ*
f(PCVN)). The σ*
f(sp) shows a lower value
than σ*
f(PCVN) because the SP specimen had a lower triaxial stress condition. However, this result
indicates that a small punch test could be a useful method to evaluate the cleavage fracture behavior
of low alloy steels.
Mode III Yoffe Dynamic Crack Problem on the Interface between Dissimilar Materials
Authors: Jin Cheng , Li Xin Gang , Zhang Li
Published: March 2009

A moving crack in a laminated structure with free boundary subjected to anti-plane shear
loading is investigated in this paper. Using the bonding conditions of the interface between different
media, all the quantities in our question have been represented with a single unknown function, and
the problem is transformed into a dual integrated equation with the method of Fourier transform.
The equation is solved using Schmidt method. Finally the numerical results show the relationships
among the dynamic stress intensity factor and crack velocity, the height of different laminated
material, shear moduli of different laminated material.
Effect of Microstructure on Thermo-Mechanical and Isothermal Low Cycle Fatigue Failures of a Single Crystal Ni-Base Superalloy
Authors: Sakaguchi Motoki , Okazaki Masakazu
Published: March 2009

Behavior of thermo-mechanical fatigue (TMF) failure of a single crystal Ni-base
superalloy, CMSX-4, was studied and, compared with isothermal low-cycle fatigue (ILCF) of it.
Strain-controlled TMF and ILCF tests of CMSX-4 were carried out under various test conditions,
where the experimental variables were strain rates, strain ratio, test temperature and the range, and
strain/temperature phase angle. At first it was shown from the experiments that the TMF and LCF
failures associated with some noteworthy characteristics were rarely seen in the traditional
pollycrystalline heat-resistant alloys. These phenomena could be explained inadequately, on the
basis of the macroscopic parameters and the historical failure criteria; e.g., Manson-Coffin law and
Ostergren approach. A new micromechanics model is proposed to predict the TMF and LCF lives,
based on the Eshelby's theory.
The Study on Failure Behavior and Low Cycle Fatigue Life of Hot Gas Casing for Gas Turbine
Authors: Kim Jae Hoon , Kim Duck Hoi , Kim Kyoung Joo , Sim Woo Sung , Lee Young Shin , Park Won Shik
Published: March 2009

In this study, failure behavior of hot gas casing for gas turbine was investigated. The
microstructure and damage mechanism of serviced hot gas casing were examined. Also low cycle
fatigue tests of the Inconel 617 super alloy is used for structural material of hot gas casing were
performed. To predict the low cycle fatigue life, Coffin-Manson and strain energy density methods
were used.
The Grain Size and Porosity Dependent Constitutive Modeling for Nanocrystalline Ceramics with Small Plastic Deformation
Authors: Zhou Jian Qui , Li Yuan Ling
Published: March 2009

In order to understand the grain size and porosity dependent mechanical behavior of porous,
multi-phase nanocrystalline ceramics, each phase is treated as a mixture of grain interior and grain
boundary, and pores are taken as a single phase. In conjunction with the secant-modulus approach and
iso-strain assumption, Budiansky’s self-consistent method is extended to build a constitutive model
for nanocrystalline ceramics with small plastic deformation. Based on the developed model, the
predicted yield strength (σ0.2) values of porous, multi-phase nanocrystalline ceramics with different
grain size and porosity are compared with experimental data in the literature, the comparison shows
that the predictions are in good agreement with the published data. This suggests that the developed
model is capable of describing the grain size and porosity dependent mechanical behaviors of
nanocrystalline ceramics with small plastic deformation.
Effect of Original Microstructure on the Hot Compression Behavior of Superalloy 718
Authors: Wang Y. , Shao Wen Zhu , Zhen Liang , Lin L. , Zhang Xin Mei
Published: March 2009

Hot compression tests at different temperatures and strain rates were performed on
superalloy 718 annealed at 1100 °C for 30 min as well as 950 °C for 30 min in order to investigate
the effect of the original microstructure on the hot deformation behavior. The results show that the δ
phase precipitated on the grain boundaries of superalloy 718 prior to hot deformation leads to a
decrease of the flow stress, which can be attributed to the drop of the matrix strength. The activation
energy (Q) for hot deformation of the fine-grained material with δ phase on the grain boundaries is
determined to be 381 kJ/mol, which is much lower than that of the coarse-grained material without
δ phase (472 kJ/mol). It is suggested that the initial δ phase precipitated on the grain boundaries of
the annealed material affect the thermal activation process of hot deformation for superalloy 718,
resulting in the decrease of activation energy.
Artificial Neural Network Models for Predicting Flow Stress and Microstructure Evolution of a Hydrogenized Titanium Alloy
Authors: Wang Qing , Lai J. , Sun Dong Li
Published: March 2009

The effects of hydrogen contents and processing parameters of hot deformation on a
Ti-6Al-2Zr-1Mo-1V alloy were investigated. Hot compressive tests were conducted at different
temperatures and strain rates with various hydrogen contents. Based on these experimental data, the
simulation models for predicting flow stress and microstructure evolution have been built by back
propagation (BP) neural network. The numerical results gained via the networks were compared
with the experimental results.
Stiffness and Thermal Conductivity of Carbon Nanotube Containing Aluminum
Authors: Sasakir Katsuhiko , Imanishi Terumitsu , Katagiri Kazuaki , Kakitsuji Atushi , Satoh Toyohiro , Shimizu Akiyuki , Nakama Nobuhito
Published: March 2009

In this paper, carbon nanotube (CNT) containing aluminum composite materials, which
have good thermal conductivity, are made by the plasma activated sintering. CNT and vapor-grown
carbon fiver (VGCF) as a super multi-wall CNT are used for the composite materials. To clarify the
deformation and thermal characteristic of the composite materials, Young’s modulus and thermal
conductivity are measured. Finally, the micromechanical discussion is also conducted using
Mori-Tanaka model.
Influence of Temperature and Heat-Aged Condition on the Deformation Behavior of Rubber Material Using SHPB Technique with a Pulse Shaper
Authors: Lee Ouk Sub , Han Yong Hwan , Kim Dong Hyeok
Published: March 2009

The Split Hopkinson Pressure Bar (SHPB) technique with some special experimental
apparatus can be used to obtain the dynamic material behavior under high strain rate loading
conditions. An experimental technique that modifies the conventional SHPB has been developed for
measuring the compressive stress strain responses of materials with low mechanical impedance and
low compressive strengths such as rubber. This paper uses PEEK (Poly-ether-ether-ketone plastic)
bars to achieve a closer impedance match between the pressure bar and the specimen materials. In
addition, a pulse shaper is utilized to lengthen the rise time of the incident pulse to ensure stress
equilibrium and homogeneous deformation of the rubber specimen. It is confirmed that the
modified technique is useful to record the dynamic deformation behavior of rubbers under various
conditions such as high strain rate with various temperature effect. Furthermore, the dynamic
deformation behaviors of heat-aged rubber material under compressive high strain rate are
evaluated using the modified SHPB technique.
Fatigue Reliability Research on RD2 Axle of Railway Freight Car
Authors: Yang Bing , Zhao Yong Xiang
Published: March 2009

Considering the difference between specimens and RD2 axle of C64A freight car, the
extrapolated probabilistic fatigue S-N curves of LZ50 axle steel, which include the long life regime of
material, are adjusted by introducing a probabilistic fatigue affecting factor, Kaffect. Based on the
adjusted curves, fatigue reliability research on the axle at different operating speeds is carried out. It
utilizes the fatigue stress spectrums of the axle in two different wheel set states, namely, normal state
and scratched state. The fatigue operating life with arbitrary survival probability and confidence is
obtained, and the failure rate with given confidence and design fatigue life is also achieved. Analysis
results indicate that the unloading groove of existent RD2 axle is the most dangerous part. When the
wheel set is in normal state, fatigue life of C64A freight car RD2 axle decreases with the increase of
reliability. Furthermore, scratched wheel set shortens the fatigue life strongly. Therefore, inspection
and administration of scratched wheel set are significant. The application of wheel set at relatively
high scratch level and high operating speed should be restricted.
Compressive Deformation of ZK60 Magnesium Alloy at Elevated Temperature
Authors: Wang Chun Yan , Wu Kun , Zheng Ming Yi
Published: March 2009

The high temperature compressive tests of squeeze casting ZK60 magnesium alloy with
temperatures of 573-723K and strain rate in the range of 0.001-1s-1 were performed on
Gleeble-1500D thermal simulator testing machine. Optical microscopy was performed to elaborate
on the dynamic recrystallization (DRX) grain growth. TEM findings indicate that mechanical
twinning, dislocation slip, and dynamic recrystallization are the materials typical deformation
features. Variations of flow behavior with deformation temperature as well as strain rate were
analyzed. Analysis of the flow behavior and microstructure observations indicated that flow
localization was observed at lower temperature and higher strain rates, which should be avoided
during mechanical processing. Dynamic recrystallization occurred at higher temperature and
moderate strain rates, which improved the ductility of the material. The optimum hot working
conditions for ZK60 alloy were suggested.
Texture Development during Cold and Cryogenic Rolling in AA 7055 Aluminum Alloy
Authors: Chen J.Z. , Zhen Liang , Zhang Bao You , Cui Y.X. , Dai Sheng Long
Published: March 2009

The texture evolution of polycrystalline AA 7055 aluminum alloy during rolling about
15% and 50% at room temperature and cryogenic temperature has been investigated by electron
back-scattered diffraction (EBSD). With increasing the rolling reduction, the intensities of the
components of the β fiber increase at both rolling temperature and simultaneously, the shear
textures disappear gradually. The lattice rotation paths from the {001}<110> orientation to β fiber
was discussed.
Characteristic of Deformation of Ti-6Al-4V Alloy with Hydrogen at High Temperature
Authors: Li Zhong Hua , Wang Qing , Sun Dong Li , Zhang Li Ping
Published: March 2009

The effects of hydrogen on the microstructure and hot deformation behavior of Ti-6Al-4V
alloy were studied, and the differences of microstructure and high temperature compressive behavior
between the specimens hydrogenised various time at 700 oC and with the same hydrogen contents
were analyzed. The results showed that the addition of hydrogen decreases the deformation resistance
of Ti-6Al-4V alloy at high temperature. The flow stresses of specimens with the same hydrogen
content declined as the prolongation of hydrogenating time. The microstructure observation indicated
that stick-type microstructure was obtained in Ti-6Al-4V alloy annealed at 700 oC for 2 hours.
Hydrogenation at 700 oC for 2 hours resulted in fine α plate in β transformed microstructure. When the
hydrogenation time was prolonged to 6 hours, the volume fraction of newly-formed α plates increased
and the prior α plates became coarser.
Study on Complete Stress-Strain Experiment and Destruction Characteristics of Rock under Lower Confining Pressure
Authors: Han Li Jun , He Yong Nian , Zhang Hou Quan
Published: March 2009

A complete stress-strain experiment curve, gained through exerting low confining pressure
on brittle rock, reflects the deformation and destruction process of rock under different confining
pressure, and reveals that after the destruction of rock, not only slip deformation but also
re-destruction process will take place, which would possibly lead to further reduction of the
mechanical properties of the rock mass. Through the analysis of the relation between complex failure
modes, load carrying capacity after rock destruction and the volumetric strain, the paper gives us a
further explanation of the complex destructive process of rock. The basis for the rock’s load-carrying
capacity after destruction is an effective restraint stress, which shows that effective supporting in
underground engineering is the key factor for providing the cracked surrounding rock with
load-carrying capacity and guaranteeing the stability of the structure.
Tilt of Atomic Force Microscope Cantilevers: Effect on Friction Measurements
Authors: Wang Fei , Zhao Xue Zeng
Published: March 2009

The cantilevers of atomic force microscope (AFM) are mounted under a certain tilt angle,
which is commonly assumed to have negligible effect on friction measurements in AFM. We
present a theoretical study of the effect of the tilt angle on AFM based friction measurements. A
method for correcting the friction coefficient between sample surfaces and AFM tips is also
presented to minimize the effects of the tilt. The frictional forces between a silicon tip and a silicon
surface at tilt angles ranging from 5 degrees to 25 degrees were measured. The results show that the
measured friction coefficient increases with the tilt angle effectively, whereas the variation range of
the corrected friction coefficient is within 10%.
Study on Characteristics of Vibration Friction for Pile-Soil System
Authors: Li Xiao Peng , Li He , Han Qing Kai , Liu Jie , Wen Bang Chun
Published: March 2009

Vibratory pile driver-extractor is broadly applied in civil constructions, but the friction
vibration theory and dynamic characteristics of friction vibration are not studied well. In this paper,
the vibration friction characteristics and dynamics of pile driving process are studied based on
nonlinear dynamics and friction theory. A dynamic model of system is established firstly, and then
nonlinear dynamic principle and working process are studied in details. The simulation results can
provide useful guidance for both vibration friction research in engineering and design in the
development of such machines.
The Effect of the Microstructure on the Wear-Resistance in the Welding Deposited Metal
Authors: Zhang Yuan Bin , Luo Hui , Wang Guo Fan
Published: March 2009

The microstructure and wear-resistance of the welding deposited metal of Fe-Ti-Nb-V-C
and Fe-Cr-W-Mo-C alloy system (with American MG700 as example) are studyed by using SEM ,
TEM and MM200 wear testing machine. It is revealed that Ti and Nb promote the formation of
dispersed MC type carbide granules, while the carbides of Cr and W or Mo tend to precipitate along
grain boundary. The formation of MC carbide granules depletes the carbon content in the matrix,
and then low carbon martensite matrix can be achieved. The hard and tough matrix and the granular
carbides improve the wear-resistance of the deposited metal. But excessive Ti and Nb induce the
formation of bigger granules with sharp corner and result too soft matrix, then the wear-resistance
decrease. As to the Fe-Cr-W-Mo-C alloy system, network carbides and high carbon martensite
matrix make the deposited metal very brittle. During wearing process, the propagating of
microcrack in the matrix induces lots of scraps flake off, which decrease the wear-resistance of the
deposited metal. The deposited metal of Fe-0.64Ti-1.18Nb-2.18V-1.43Cr-0.97C alloy system in
current study achieve the best wear-resistance.
Capillary Adhesion between the Micro-Cantilever and the Substrate
Authors: Peng Yun , Li Xi De , Kui Wen
Published: March 2009

In Microelectromechanical System (MEMS), the capillary force plays an important role
owing to the strong capillary force often makes the suspended or moving structures in MEMS adhere
to contact the substrate, which lead to the failure of the devices. This paper presents experimental and
theoretical results that characterize the capillary adhesion of micro-cantilevers by means of capillary
actuation. Micro-cantilever beams were loaded at various locations along the freestanding portion of
the beam using the capillary force and the deflections of the beams were real-time and in-situ
measured with micro speckle interferometry. The mechanical stability and adhesion of
micro-cantilever under capillary forces were examined and the deflecting configurations of the beams
and the relationship of the magnitude of the capillary force to the size of the specimen were presented.
Gear Abrasion-Induced System Vibration
Authors: Han Zhi Xin , Liu Bing , Du Jin Xia , Wang Shao Feng
Published: March 2009

The vibration motion and the sliding ratio of the gear system were analyzed. It was
revealed that the system vibration may make the meshing point at the middle of the tooth surface
move in reciprocating motion and therefore may increase relative-sliding and the abrasion between
two tooth surfaces meshed. So it can be concluded that the abrasion may result in the system
vibration.
A Simulation of Hydrodynamic Lubrication on Non-Glazed Surfaces under Different Sliding Velocities and Loads
Authors: Li Peng , Li Jian , Zhang Yong Zhen , Scherge M.
Published: March 2009

Recent researches have found that surfaces with non-glazed or laser dimpling topography
offer improved lubricating efficiency and wear resistance under lubrication conditions over their
conventional glazed status. It was carried out in this paper to simulate a pin-on-disk experimental
condition and perform hydrodynamic lubrication (HL) calculations for both non-glazed and glazed
surfaces under conditions of different sliding velocities and loads with a view of understanding the
tribological mechanism and characteristics of non-glazed surfaces. The results showed that the
minimum film thickness of non-glazed surfaces, which closed to a typical elasto-hydrodynamic
lubrication (EHL) film thickness, was thicker than that of glazed surfaces under the condition of
low sliding velocities and small loads. At the same time, a decreased maximum pressure of full-film
of non-glazed surfaces demonstrated an even pressure distribution on them.