bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Damage Mechanism of Pipe Using Ultrasonic Wave and Acoustic Emission Technique
Authors: Lee Jin Kyung , Lee Sang Ll , Lee Joon Hyun
Published: March 2009

A study on corrosion evaluation by using ultrasonic waves and acoustic emission technique
is presented. The experimental equipment was established to improve the corrosion process of carbon
steel pipe. The carbon steel pipe was under 473K temperatures and 10Mpa pressure conditions, and
ultrasonic wave and acoustic emission techniques were used to inspect the degree of corrosion after a
certain period of time. Ultrasonic bulk waves are limited by the poor time resolution when used in the
measurement of corrosion depth in thin wall structures because the corroded surfaces cause unclear
echo signal edges. Therefore, in this study, the ultrasonic guided waves were generated on the pipe
because the thickness of pipe was thin. Various wave modes were subsequently generated on the pipe
to evaluate the implications of corrosion thinning on group velocity, transmission and reflection
amplitudes. The amplitudes of the transmitted and the reflected waves are influenced by couplent
material. In order to reduce the effect of coupling acoustic emission sensor was used. Acoustic
emission technique has lots of parameters to evaluate the corrosion besides amplitude parameter.
Among parameters energy, count, and frequency were useful parameters to measure the degree of
corrosion inside the carbon steel pipe under 473K temperatures.
Measurement of Residual Stress in Water Pipe Welds Using the Hole-Drilling Technique
Authors: Choi Jung Hun , Baek Jong Hyun , Kim Dae Jin , Koo Jae Mean , Seok Chang Sung
Published: March 2009

In case of large steel water pipe, it have been observed that its fracture mostly occurs due to
the complicated outside fatigue load on the pipe in the underground. It is also well known that its
damage and leakage happen mainly in a weld zone. In this study we evaluated the fatigue
characteristics based on size effect and residual stress by comparing the test results on the standard
specimen collected from real pipe with those on full scale pipe.
X-Ray Stress Measurement of Fiber Reinforced Plastics Composite Material
Authors: Masayuki Nishida , Takao Hanabusa , Ikeuchi Yasukazu
Published: March 2009

X-ray stress measurement with sin2ψ method is one of useful tools to detect residual
stresses in manufactured products. In this study, the residual stresses in the tungsten fiber reinforced
polyethylene composite were examined by X-ray stress measurement technique. The transmission
diffraction method was employed in residual stress measurement of polyethylene matrix. The X-ray
elastic constant of high density polyethylene (HDPE) which formed matrix of the composite was
estimated before residual stress measurement. The results of sin2ψ diagram with transmission
method show good linearity under the several tensile loading. After that the residual stresses in the
composite were investigated for HDPE matrix phase. From the measurement results, the tensile
residual stresses existed in fiber longitudinal direction and compressive ones in transverse direction
for HDPE matrix.
Damage Detection and Quantitative Assessment for the Cracked Beam Structures
Authors: Hong Yong , Kim Byung Jin , Hong Dong Pyo , Kim Young Moon
Published: March 2009

Beam structures are a common form in many large structures, and therefore the real-time
condition monitoring and active control of beams will improve the reliability and safety of many
structures. However, the incipient damage, i.e. cracks, is not easy to be detected with using the
traditional methods, such as modal analysis, etc. Piezoceramic (PZT) sensors offer special
opportunities for the health monitoring of structures constructed by beams. The change of
mechanical impedance of structures along with the occurrence of damage is sensitively indicated by
the change of electro-impedance of PZT sensors. This paper presents work done on developing and
utilizing PZT sensors to detect and quantitatively assess the extent and locations of cracks occurred
in simulated structures. The PZT sensors are conducted particularly to generate the longitudinal
wave along the beam specimen, and systematic experiments conducted on statistical samples of
incrementally damaged specimens were used to fully understand the method, the cracks with
different length and location are simulated to indicate the feasibility of the detection and assessment.
To estimate the damage conditions numerically, in this paper, we propose the evaluation method of
impedance peak frequency shift F and CC (Correlation Coefficient), Cov (Covariance). The
results of experiments verify that the impedance peak frequency shift Δ F uniformly assesses the
location of cracks, and as well CC. and Cov assesses the size of cracks efficiently. The study
presents the method that is satisfied for much higher frequencies, alternate power, and minute
damages.
Influence of Observation Errors on the Identification of External Loads
Authors: Rong Gui Ming , Kisu Hiroyuki
Published: March 2009

This paper will report on the investigation results of the influence of observation errors
on the identification of external loads in case of the bending problem of a beam. It is found that the
resultant force and the resultant moment of the loads will be conserved despite of the divergence of
the identified load distribution, when the observation errors are within a certain tolerance. This fact
is applicable to the problem of identifying a small defect.
Study on Looseness and Impact - Rub Coupling Faults of a Vertical Dual-Disk Cantilever Rotor- Bearing System
Authors: Lu Yan Jun , Ren Zhao Hui , Chen Hong , Song Nai Hui , Wen Bang Chun
Published: March 2009

Because of wrong setting or long-term running of rotating machinery, the looseness may
ouur in the bearing seats or bases. And also bring impact and rubbing of rotor-stator, That is the
looseness and rub-impact coupling fault. In the paper,a mechanics model and a finite element model
of a vertical dual-disk cantilever rotor- bearing system with coupling faults of looseness and
rub-impact are set up. Based on the nonlinear finite element method and contact theory, the
dynamical characteristices of the system under the influence of the looseness rigidity and
impact-rub clearance is studied. The results show that the impact-rub of rotor-stator can reduce the
low frequency vibration caused by looseness, and the impact-rub caused by looseness has obvious
orientation. Also, the conclusion of diagnosing the looseness and rub-impact coupling faults is
given in the end of the paper.
Investigation on Levitation and Restitution Mechanisms of FPD Air Handling System
Authors: Chang Yoon Suk , Cho Dae Geun , Lee Sang Min , Choi Jae Boong , Kim Young Jin , Chun Poong Hwan , Kong Jae Youn
Published: March 2009

The purpose of this paper is to investigate principles of levitation and restitution of blowing
nozzle prior to fabricating a prototype of air handling system. Since air force distributions streaming
bottom surface of a flat panel display (FPD) highly dependent on operating as well as design condition
and configuration of air handling system, influences of various parameters such as flow rate, supply
air pressure, floating height and tilted angle are examined through a series of computational fluid
dynamics (CFD) analyses. Moreover, dynamic finite element analyses of the FPD are carried out to
assure that an oscillation effect caused by disturbances is not significant. Key findings from the both
CFD and structural analysis results are presented and discussed, which can be utilized as technical
bases for development of the practical air handling system.
Stability Analysis of Cut Rock Slope with Reinforcement by Steel Cables
Authors: Wang Shui Lin , Lu Ying Hui , Jiao Yu Yong , Li Chun Guang
Published: March 2009

There are a large number of cracks, joints and layers with different scales and
orientations in the rock masses. With the structural formation in it, the rock mass is unlike the
isotropic and homogenous materials in physics and mechanics characteristics, and the failure of the
rock mass is controlled by those discontinuities. This paper studies the stability of a jointed rock
slope with bedding-planes. Universal Distinct Element Code (UDEC) is used to carry out the
numerical analysis. The factor of safety (FOS) and failure mode are obtained by strength reduction
technique before and after the steel bolts are installed in the slope. In addition, the forces along the
bolts indicate that they reaches the maximum value in the potential slip surface of the slope.
The Relation of the Geometric Parameters to the Maximal Principal Stress of Crankshaft
Authors: Han Da Fei
Published: March 2009

he transition fillet regions linking the bell crank and the crank-arm and linking the crankarm
and the bearing journal are the regions where the strength is the weakest in crankshaft. Based
on a crank-shaft model, the effect of the geometric parameters on maximal principal stress at the
two transition fillet regions was analyzed using FEM and software ANSYS8.0. It was concluded
that the maximal principal stress at the two transition fillet regions is related not only to the
transition fillet radius but also to the bell crank length and the crank-arm width.
Analyzing the Strength and Stability of Large Underground Cavern Group with Different Generator Socket Construction Schemes Based on Three Dimensional Numerical Simulation
Authors: Jiang An Nan
Published: March 2009

Shuibuya hydroelectric project is the most upstream power station in the Qingjiang
cascade development of China. The power plant is designed as underground powerhouse, from
seventh to eighth construction step, how to ensure the stability of surrounding rock mass of
generator socket and controlling the displacement of lower side wall where the soft stratum located
in is a key problem. To solve the problem, the three dimensional numerical model of the
underground powerhouse was established based on the results of geological investigation. Then, the
detailed construction processes, including the replacement of soft rock, excavation as well as
support, were numerically simulated. In order to improve the simulation accuracy, the rock
mechanics parameters were back analyzed based on in-situ monitor data before sixth construction
step, then using Mohr-Coulomb criterion, the paper simulated and analyzed the damage zones of
surrounding rock and displacement of lower side wall corresponding to different schemes. The best
scheme was recommended by synthetically considering the stability indexes of each scheme. The
study had a scientific meaning to guide Shuibuya project construction.
Introduction
When the underground cavern is excavated, the initial ground stress is released
First Passage of Uncertain Nonlinear MDOF Systems with Uncorrelated Failure Modes
Authors: Zhang Yi Min , Li He , Liu Qiao Ling , Wen Bang Chun
Published: March 2009

The failure analysis of uncertain multi-degree-of-freedom (MDOF) nonlinear vibration
systems with uncorrelated failure modes subjected to random excitation is examined. An earlier
version of the statistical fourth-moment method is extended to vector-valued and matrix-valued
functions and is developed to determine the first four moments of the system response and state
function. Random variables and system derivatives are conveniently arranged into 2D matrices by
means of Kronecker products. The distribution function of the system state function is
approximately determined by the standard normal distribution functions using Edgeworth series
technique and its failure probability is obtained. The method is based on matrix calculus. Kronecker
algebra is used in the mathematical development.
Effects of Various Types of Distribution on Probabilistic Method and FAD
Authors: Lee Ouk Sub , Kim Dong Hyeok
Published: March 2009

The reliability estimation of pipeline is performed in accordance with the probabilistic
methods such as the FORM (first order reliability method) and the SORM (second order reliability
method). A limit state function has been formulated with help of the FAD (failure assessment
diagram). Various types of distribution of random variables are assumed to investigate its effect on
the failure probability. It is noted that the failure probability increases with the increase of the dent
depth, the operating pressure and the outside radius, and the decrease of the wall thickness.
Furthermore it is found that the failure probability for the random variables having the Weibull
distribution is larger than those of the normal and the lognormal distributions.
The Non-Local Theory Solution of a Crack in the Functionally Graded Piezoelectric Materials Subjected to the Harmonic Anti-Plane Shear Stress Waves
Authors: Zhou Zhen Gong , Wu Lin Zhi
Published: March 2009

In this paper, the non-local theory of elasticity was applied to obtain the dynamic behavior
of a Griffith crack in functionally graded piezoelectric materials under the harmonic anti-plane shear
stress waves. The problem can be solved with the help of a pair of dual integral equations. Unlike the
classical elasticity solutions, it is found that no stress and electric displacement singularities are
present at the crack tips, thus allows us to use the maximum stress as a fracture criterion.
Optimal Placement of Multi Circular Heat Sources of HANARO Irradiation Test
Authors: Lee Young Shin , Choi Young Jin , Kang Young Hwan , Lee Youn Bok
Published: March 2009

During fuel irradiation tests of material and fuel rods, all parts of cylindrical shells with
multiple holes act as heat sources due to fission heat and γ-flux. The thermal stress is induced by a
temperature difference among the heat sources. In this study, the thermal stress of the cylindrical
structure is minimized by using an optimization method about the geometric variables. The circular
shapes of the multi-specimens are investigated. For the thermal analysis of the structure, the finite
element method code, ANSYS 8.1 is used. A sub-problem approximation method is used for the
structural design optimization.
Corrosion of 16Mn in High Pressure Carbon Dioxide Saturated NACE Solutions with Hydrogen Sulfide
Authors: Zhou Qi , Liu Jian Jun , Ma Qin , Ji Gen Shun , Guo Tie Ming , Jia Jian Gang
Published: March 2009

The paper deals mainly with the corrosion of 16Mn steel under the condition of three
different high temperatures and in NACE solution saturated with H2S at 1MPa partial pressure of
CO2, by means of autoclave, SEM, XRD, weight loss method and electron-probe micro-analysis.
The result showed: under the experimental conditions, the serious CO2/H2S corrosion happened to
16Mn steel ,so that the main corrosion films, ferrous sulfide, could be clearly found on both sides of
the samples; at 60°C, characteristics of pitting corrosion manifested centered chiefly around CO2
corrosion ; at 90°Cand 120°C, around H2S ones . It was the cooperating effects of both the
hydrogen damage and pitting corrosion caused by CO2/H2S corrosion that formed the special
corrosion features on the surface of steel to a certain degree. It was indicated that the corrosion of
CO2/H2S was the result of interaction of multi-factors.
Resonance Reliability Assessment of Turbine Blade with Parametric Uncertainty
Authors: Ge Yong Qing , An Li Qiang , Wang Zhang Qi
Published: March 2009

Stochastic finite element method and reliability technique are used to determine the
safety degree of the turbine blade with parametric uncertainty. The material, geometric parameters
and rotating speed of blade exhibit notable random fluctuations, so the conventional deterministic
analysis of blade can’t provide complete information. The stochastic analysis can tackle the
uncertainties in structural parameters and obtain the probabilistic characteristic of the vibration
characteristic. In this paper, the study focuses on the reliability assessment of the blade with
uncertainty parameters based on the stochastic finite element method (SFEM) and the
mean-variance method. The perturbation stochastic finite element method (PSFEM) is used to
calculate probabilistic characteristic of the natural vibration of the turbine blade. Based on the
stochastic finite element method, the mean-variance method is used to calculate the resonance
reliability of the blade. The example shows that the present method is valid.
Increasing Damping Ratios in a Tuned Liquid Damper Using Damping Bars
Authors: You Ki Pyo , Kim Young Moon , Yang Cheol Min , Hong Dong Pyo
Published: March 2009

Wind-induced vibration of tall buildings have been of interest in engineering for a long
time. Wind-induced vibration of a tall building can be most effectively controlled by using passive
control devices. The tuned liquid damper(TLD) is kind of a passive mechanical damper, which relies
on the sloshing liquid in a rigid tank. TLD has been successfully employed in practical mitigation of
undesirable structural vibrations because it has several potential advantages: low costs, easy
installation in existing structures, and effectiveness even against small-amplitude vibrations. Shaking
table experiments were conducted to investigate the characteristics of the shallow water sloshing
motion in a rectangular tank. To increase the damping ratio of the rectangular water tank, triangle
sticks were installed at the bottom of water tank. This installation increased the damping ratio by
amaximum of 40-70%.
Structural Response and Behavior Analyses of Steel Joint Components at Elevated Temperatures
Authors: Wei Dong , Sun Xiu Shan , Zhu Jian Ming , Liu Ying Hua
Published: March 2009

The structural response and behavior of steel joint under fire condition are analyzed in
this paper. A simplified model for moment-rotation relationship of the end-plate bolted connections
at elevated temperatures is proposed. This model is convenient and effective to describe the
characteristics of extended end-plate joint and can be applied to evaluate the structural response and
fire-resistant performance under static-load and thermal effects. The results of finite element
analysis and related experiment are also used to validate the proposed model. It is found that the
initial rotational stiffness and limit loading-capacity of steel joint components are affected
significantly by the degradation of materials and the dimensions of components.
Stability Analysis on Surrounding Rockmass of Deep Tunnel Based on YAI and FD Concepts
Authors: Zhou Hui , Zhang Chuan Qing , Feng Xia Ting , Chen Bing Rui
Published: March 2009

This paper proposes two concepts in order to estimate the stability of surrounding rockmass
of deep tunnel, one is YAI (yielding approach index) which is used to denote the stability difference
among the zones in surrounding rockmass whose stress states are close to yielding, the other is FD
(failure degree) which focuses on the estimation of failure degree of the zones in surrounding
rockmass and can be calculated by the equivalent plastic strain when failure occurs. Finally, a
numerical analysis on the excavating process of a deep tunnel is performed, and YAI and FD are used
to estimate the stability states of rockmass. The accurate estimation on plastic field and the proper
evaluation on stability state indicate that these two concepts are rational and of perfectly practical use.
Performance Evaluations of the 3rd Rail Type Power Collector for Rubber-Tired Vehicles
Authors: Kim Yeon Su , Park Sung Hyuk , Jeong Rag Gyo , Mok Jai Kyun
Published: March 2009

This study was aimed to verify the performance and stability of the 3rd rail type power
collector for rubber-tired vehicles. Performance (power interruptions), durability (stresses), stability
(vibrations and contact force variations) of the developed power collector were measured and
analyzed, while the rubber-tired vehicle ran at various speeds on the test track(about 2.4km).
Analysis of Performance Characteristics in Deteriorated Subway Rolling Stock
Authors: Kim Jeong Guk , Yoon Sung Cheol , Kwon Sung Tae , Seo Jung Won , Park Kyung Taek
Published: March 2009

In order to investigate performance characteristics of deteriorated subway rolling stocks,
several engineering assessment methods, such as the acceleration, vibration, and braking
performance tests, were carried out on subway electric multiple units (EMUs) with over 20 years
operation. According to the testing results, in vibration and braking performance of EMUs, the
similar performance results were obtained as compared with newly manufactured EMUs. However,
in terms of acceleration performance characteristic, below reference value (3.0 km/h/s) has been
obtained. This is mainly due to performance deterioration of EMUs including traction motor. In this
investigation, the results on precision diagnosis evaluation of deteriorated EMUs were provided
through the overall evaluation of corrosion testing and structural performance of car body in
subway EMUs.
An Enhanced Pre & Post Processing Technique for the Three Dimensional Tunnel Analysis: Tunnel Modelling Wizard
Authors: Shin Dae Seock , Lee Heung Shik , Cho Chong Du , Shin Jong Ho
Published: March 2009

An enhancement to pre & post processing techniques, which is encapsulated in ‘Tunnel
Modelling Wizard (TMW)’ for three dimensional tunnel analysis, is developed and described in this
paper. The techniques include geometry modelling, mesh generation, virtual transformation, flying
view and utilization and interpretation of analysis results. The TMW automatically generates full
analysis data including mesh, loads, boundary conditions and construction stages from the
user-defined parameters. The TMW also provides its own file I/O service to help users expedite
modelling tasks for similar models and build their own tunnel templates. Implementation of the TMW
into a FE Program is described, and applications of the TMW to practical tunnel problems will be
demonstrated.
Fatigue Design of Gas Welded Joint for the Railroad Car Body Using the Hot Spot Stress
Authors: Bae Dong Ho , Kim Yeong Sin , Lee Gyu Young
Published: March 2009

In order to establish a reasonable and integrated fatigue design criterion for the long life
design of the gas welded body structure, stress distribution around the gas welded joints subjected
to tensile load was numerically analyzed. And also, the P-Nf curves were obtained by fatigue tests.
By using these results, P-Nf curves were rearranged in the σ-Nf relation with the hot spot stress at
the welded joint. And a guideline for fatigue design of gas welded joints was proposed.
Mechanical Behaviors of a Power Steering Hose Assembly during the Swaging Process
Authors: Kim Byung Tak , Kim Seon Jin , Koh Sung Wi , Kim H.J.
Published: March 2009

In this study, finite element analyses for the mechanical behaviors of a power steering hose
assembly during the swaging process were performed in order to investigate the stress level of hose
components according to jaw strokes, and to examine the effect of friction coefficient on the contact
force. The physical properties such as Mooney-Rivlin constants of rubber materials and the
work-hardening data of the steel were obtained through the experiments, and the contact conditions
identical to the swaging process were taken into account. Two reinforced layers included in the hose
were modeled with axisymmetric rebar elements in the general-purpose program, MSC MARC2000.
The updated Lagrange formulation and the large displacement option were employed in the analysis.
The result interpretations were focused on the rubber components which are in contact with the metal
components, because of their important roles in the hose efficiency.
Effects of Nano Fillers on the Conductivity, Adhesion Strength and Reliability of Isotropic Conductive Adhesives (ICAs)
Authors: Li Qing Hua , Zhang Jian Hua
Published: March 2009

Isotropic Conductive Adhesives (ICAs) were prepared using epoxy resin as matrix, latent
curing agent as hardener, and silver particles as the conducting filler. The effects of nano-fillers
(SiO2 nano-particles and carbon nanotubes) on the conductivity, adhension strength and reliability
of ICAs were investigated experimentally in this paper. The results showed that these two nano
fillers can improve both the conductivity and adhesion strength of ICAs, which maybe attributed to
the nano-particles forming physico-chemical bonds with epoxy resin. These physico-chemical
bonds increase the contact area and then minish the interspace of Ag particles, so it reduces
electrical resistance and enables a high current flow. And the increasing contact area will improve
the contact strength between Ag particles and epoxy resin. Under the reliability testing with the high
temperature and high humidity (85°C/85RH), the SiO2 nano-particles can improve the reliability of
ICAs apparently, while carbon nanotubes can not. This is because insulating material can prevent
silver migration.
Thermal Stress Analysis of MCM Package Using Diamond Material
Authors: Xie Kuo Jun , Jiang Chang Shun , Zhu Lin , Xu Hai Feng
Published: March 2009

With the increasing of packaging integration the power and the quantity of heat of
integrate circuit will increase, it will bring more and more temperature distributions and problems
about thermal stresses in package. In this paper a finite element thermal stress model of
substrate-adhesive-chip is established, thermal stress distribution of substrate-chip interfaces and
the affects of geometrical structure on thermal stresses are analyzed by finite element method,
especially discuss interfacial thermal stresses distributions on chip-adhesive interface and
adhesinve-substrate interface.
Crack Propagation Behavior at Sn37Pb-Copper Interface in Low Cycle Fatigue
Authors: Sakane Masao , Itoh Kazuhiro , Tsukada Yutaka , Terada Kenji
Published: March 2009

This paper studies the crack propagation at Sn37Pb-copper interface in push-pull low
cycle fatigue. Bonded specimens of Sn37Pb and copper having notch holes with different distances
from the interface were fatigued at 313K and the crack propagation paths were observed. Cracks
propagated at the interface when the notch hole was near the interface but propagated in the solder
when the notch hole was away from the interface. The propagation rate of the interfacial crack was
faster than that of non-interface crack. The crack path and crack propagation rate of the two types
of cracks were discussed in relation to J integral range calculated by finite element method.
Hardness and Elastic Modulus of ZnO Thin Films Fabricated by PLD Method
Authors: Yoon Han Ki , Yu Yun Sik
Published: March 2009

ZnO is an n-type semiconductor having a hexagonal wurzite structure. ZnO exhibits good
piezoelectric and optical properties, and might be a good candidate for an electroluminescence device
like an UV laser diode. Then, these devices are very small, their films are very thin and they are
prepared in the limited size and shape, so they are unsuitable for the extensive mechanical testing. In
this present work, ZnO thin films are prepared on the glass, GaAs(100), Si(100) and Si(111)
substrates at various temperatures by the pulsed laser deposition (PLD) method. ZnO thin films were
evaluated by X-ray diffraction (XRD) and mechanical properties such as hardness and elastic
modulus were measured through the nano-indenter.
Effect of C/Ti Ratio and Al Powder Size on Microstructure and Performance of Al-Ti-C Grain Refiner
Authors: Xu Chun Xiang , Liang Li Ping , Lu Bin Feng , Zhang Jin Shan , Liang Wei
Published: March 2009

Al-Ti-C grain refiners have been prepared by combining self-propagating
high-temperature synthesis (SHS) technique and melting-casting method. Effects of Al powder size
and C/Ti ratio on the microstructures and grain-refining efficiency of Al-Ti-C grain refiners were
studied by OM, XRD, SEM and EDS. The results show that when Al powder size is fine, and C/Ti
ratio is 1: 8, SHS reaction among the mixed powders can easily carry on in the melt. As a result,
the prepared grain refiner consists of blocky Al3Ti and fine TiC particles distributed in Al matrix,
and exhibits excellent grain refining performance on commercially pure Al.
The Cutting Energy of Rubber Cutting by a Sharp Cutter
Authors: Jin Ying , Wu Jian Hua , Liu Long Quan , Yao Zheng Qiang
Published: March 2009

In order to obtain the total cutting energy and the ratios of the three parts of the total energy
during cutting off the rubber, a test method was proposed and a test apparatus was constructed to
perform the rubber cutting experiment. In the test, the friction force and the cutting force were
obtained. Through the analysis of the test results, the friction work, the deformation energy, the
surface fracture energy in cutting different thickness of the rubber were calculated. This work
originally proposed a test method to acquire the friction force, the friction work between the cutter and
workpiece during punching process.
Accuracy of Measurement of the Infinitesimal Deformation in Digital Image Correlation and the Intelligent Hybrid Method
Authors: Machida Kenji , Okazaki Kazuhiro
Published: March 2009

The displacement obtained from the experiment is including large error and it is
impossible to evaluate the stress and the strain with high accuracy using raw displacement data. The
2-D intelligent hybrid method was applied in order to evaluate the 2-D stress field. In the
infinitesimal deformation within elastic region of steel or an aluminum alloy, the quantity of
displacement is less than 1 pixel, and analysis accuracy deteriorates. We need the system which can
analyze the displacement more exactly in sub-pixel field. Hence, the Newton-Raphson method was
applied after obtaining the displacement at any point of the image. On uniform deformation field,
the infinitesimal strain was estimated with less than 0.01pixels of an error by DIC by taking into
consideration only the 1st deformation gradient in the Newton Raphson method. On nonuniform
deformation near the crack tip, it was estimated with about 0.018pixels error by taking the 2nd
deformation gradient into consideration.
Flow-Induced Corrosion Simulation on a Plate by Finite Element Methods
Authors: Zhang Qi , Chen Yang Guang , Niu Li Sha , Shi Hui Ji
Published: March 2009

Flow-induced localized corrosion is regarded as one of the main degradation mechanisms
of materials. As an initial step of the simulation of a pipe, a plate is chosen to simplify the problem. In
this paper, finite element method is used to simulate the corrosion process in the plate by employing
nonlinear geometry and physics equations of the material to describe the quasi-static process. An
elastic modulus iterative procedure was performed to obtain the material parameters in consideration
of the nonlinear physical properties of corrosion. The effect of corrosion is then considered by
introducing a criterion between depth and time, calculating corrosion depth at progressive given time.
Dead and live finite elements are employed to consider the invalidation of the material. Thus the
movable boundary conditions can be taken into account and the dynamic status of corrosion can be
simulated. Stress corrosion process under flowing fluid condition is analyzed and then the results of
representative examples are compared with published results.
Accurate Determination of Stress Intensity Factor for Interface Crack by Finite Element Method
Authors: Oda Kazuhiro , Noda Naoaki , Atluri Satya N.
Published: March 2009

This paper presents the simple method to determine the complex stress intensity factor of
interface crack problem by the finite element method. The proportional method is extended to the
interface crack problem. In the present method, the stress values at the crack tip calculated by FEM
are used and the stress intensity factors of interface crack are evaluated from the ratio of stress values
between a given and a reference problems. A single interface crack in an infinite bi-material plate
subjected to tension and shear is selected as the reference problem in this study. The accuracy of the
present analysis is discussed through the results obtained by other methods. As the result, it is
confirmed that the present method is useful for analyzing the interface crack problem.
Thermal Fatigue Properties of the Fin in the Boilers
Authors: Tokunaga Yukihiro , Yan Nu , Yonekura Daisuke , Murakami Riichi
Published: March 2009

In order to improve the heat transfer efficiency, the fins are commonly used in the
industrial boiler in Japan. In actual application, the thermal fatigue due to the cyclic change of
temperature usually occurs in the fins. The thermal fatigue tests were carried out by using the
thermal fatigue apparatus designed. The designed testing apparatus can apply thermal load to the fin
by giving heating and cooling alternatively. The fatigue cracks can be observed in the vicinity of the
toe in the thermal fatigue test. The heat transfer coefficient and the thermal stress were calculated
by using Finite Element Analysis (FEA) method. The fatigue experiments of the fins were also
conducted using electro-hydraulic servo fatigue test machine in the laboratory. The results of
thermal fatigue experiments were discussed by comparing with those of the mechanical fatigue
experiments.
Study on Fracture Mechanisms of TiAl Alloys by In Situ Tensile Tests
Authors: Cao Rui , Chen Jian Hong , Zhang J.
Published: March 2009

Combining in-situ tensile tests with detailed observations of fracture surfaces of a
two-phase TiAl alloy, the fracture process and fracture mechanisms of TiAl alloys are investigated.
The results reveal that Cracks prefer to initiate and propagate along lamellar interfaces, which are
the weakest link in the near fully lamellar microstructure. The interlamellar strength calculated is
less than the translamellar strength. The tensile stress is the driving force for crack initiation and
propagation. In specimens with a slit notch, most cracks are initiated directly from the notch root
and extended along lamellar interfaces. The main crack can be stopped or deflected into a
delamination mode by a barrier grain with a lamellar interface orientation deviated from the
direction of crack propagation. In this case, new cracks are nucleated along lamellar interfaces of
grains with favorable orientation ahead the barrier grain. The main crack and a new crack are then
linked by the translamellar cleavage fracture of the barrier grain with increasing applied load. In
order to extend the main crack, further increases of the applied load are needed to move the high
stress region into the ligament until final fracture. The process of a new crack nucleation with a
bridging ligament formation decreases the crack propagation resistance rather than increases it.
Theoretical Analysis and Experimental Research on the Braced Stress of Vacuum Glazing
Authors: Zhang Rui Hong , Kong De Jun , Yang Chao Jun , Gao J.H. , Miao H. , Ren Xu Dong
Published: March 2009

The mathematical model of the braced stress-strain in the vacuum glazing was
established with the crunode method by elastic mechanics. The braced stress-strain field of vacuum
glazing was received, and the stress-strain distribution was analyzed at the same time. Electric test
method was used to validate the stress distribution. The experimental results are shown that the
maximal stress of vacuum glazing occurs in the second braced pillar of the four-square side. The
maximal stress value by elastic mechanics is 11.057MPa, while the measured value by electric test
method is 11.765MPa, and its tolerance is only 6.02%. The positive stress in the cross section of the
braced pillar is 179MPa, the longitudinal strains of steel and glazing braced pillar are 0.2686μm and
0.7414μm, respectively. The tolerance of braced pillar height and the glazing level degree are
controlled to guarantee force equality, which increases strength, dependability, and service life of
vacuum glazing.
Study on the Strength of Jointed Rock Mass
Authors: Zhang Zhi Gang , Qiao C.S. , Li Xiao
Published: March 2009

Based on the structure of the rock mass surrounding a highway tunnel under construction,
a new methodology for defining the strength of jointed rock mass is proposed. The laboratory
experiments and numerical simulations of rock samples, including both intact rock and rock with a
single typical joint, are carried out to ensure that the mechanical parameters of the rock and the joint
can be obtained. In addition, the strength of the rock mass surrounding the tunnel, without resorting
to the difficult task of sampling and testing of large-scale rock mass, is evaluated by using the
proposed method. It is shown that the strength reduction of rock mass is governed by the geometric
configurations as well as the mechanical properties of the joints, and that the presence of joints
results in the non-linearity of the pre-peak region.
Empirical Correlation between Parameters from Small Punch and Tensile Curves of Mn-Mo-Ni Low Alloy Steels by Using Test and FE Analysis
Authors: Kim Min Chul , Lee Jae Bong , Kim Maan Won , Lee Bong Sang
Published: March 2009

A load-displacement curve from a small punch test includes several useful information
that is related to standard test properties such as the tensile property, fracture toughness and ductilebrittle
transition temperature. In this study, the empirical relationship between the material property
factors in SP curves and the tensile curves has been investigated by comparing test results and finite
element analysis results. SP and tensile tests and finite element analyses were performed for several
Mn-Mo-Ni low alloy steels with different manufacturing processes. It was found that the yield loads
(Py) in the SP curves, if they were adequately defined, were linearly related to the yield strength
(σ0). The yield loads defined from the intersection point of two lines tangent to the elastic bending
region and plastic bending region showed a better relation with the yield strength than those from
the offset line. The slope of the SP curves from the simulation results had a close correlation with
the hardening coefficient and strength constant as well.
Strength Calculation of the Screw Conveyor of a Decanter Centrifuge under Normal Operation Conditions
Authors: Huang Zhi Xin , Qian Cai Fu , Fan De Shun , Xiao Jin Hua
Published: March 2009

A parameterized 3-D finite element model of the screw conveyor of a decanter centrifuge
was established. With the model, stress analyses for the screw conveyor under normal operation
conditions were carried out and the influences of the structural parameters were investigated.
Orthogonal designs were used to sort out major factors and optimize calculations for the effects of
factors on the strength of the conveyor. With the finite element calculation results, four empirical
formulas for the strength of the conveyor under different loadings were regressed. By applying stress
superposition principle, strength check criteria under normal operation conditions were given which
can be used for the design of the screw conveyor.
Creep Model Based on Theta Projection and Omega Method for Predicting the Creep Behavior of Alloy
Authors: Song Bong Min , Kim Jong Yup , Lee Joon Hyun
Published: March 2009

Creep testing of Alloy 718 has been carried out at various loads in the temperature range
near 650°C in constant load control mode in order to understand how to predict the creep
behavior including tertiary creep. The test results have been used for evaluating the existed
models, such as Theta projection and Omega method that have been widely used for predicting long
term creep strain and rupture time. After determining variables and material parameters of each
method with the test results, estimated creep data from each model have been compared with the
each measured creep data from the creep tests. The root cause of the discrepancy between estimated
and measured data has been analyzed in order to improve the existed methods. The reliability of
the improved model has been evaluated in relation to creep data.
Comparison of the Tensile Performance of Polymer PC and PC/ABS
Authors: Fang Qin Zhi , Wang Tie Jun , Li Hui Min
Published: March 2009

Large deformation performances of polycarbonate (PC) and PC/ABS (Acrylonitrile
Butadiene Styrene) have been investigated experimentally in this paper. The displacement fields of
these polymers are measured with a system based on digital image correlation (DIC) method. The
variations of strains during tension are measured and the true stress-strain curves are presented. For
these materials, it is observed that the contraction in thickness is larger than that in width during
tension. No obvious stress softening is observed in the true stress-strain curves. The true
stress-strain curves can be fitted well with three-stage model.
Deformation Behavior of Metal Rubber Material
Authors: Li Yu Ming , Bai Hong Bai , Zheng Jian
Published: March 2009

Analysed the stress-strain test in the pressing direction of metal rubber specimen, the
deformation process can be divided into three stages. Used the accumulative method of high step
polynomial, the experience formula of metal rubber’s deformation character can be simply and
effectively established. With the fabrication and formation technology, the microscopic physics
mechanism has been analyzed in these deformation stages.
Thermal Shock Properties of Ternary-Boride-Based Cladding Material
Authors: Wang Y.G. , Li Zhao Qian , Chen Ming
Published: March 2009

Thermal shock properties of Q235A steel used ternary-boride-based (TBB) cladding
material has been studied. The result indicates that this cladding material has excellent resistance to
thermal shock and that the cracks are not difficult to occur at the interface of cladding layer and steel
substrate. The mechanism of thermal shock failure is fatigue failure brought by cycle stresses. The
thermal shock has little influence on the hardness of cladding layer. The structure of cladding layer
has no obvious change after the thermal shock, but the phase of steel substrate change from ferrite and
pearlite to martensite.
Tensile Behavior of Photonic Crystal Fibers
Authors: Yan Cheng , Yu H. , Ye Lin , Canning J. , Ashton B.
Published: March 2009

The mechanical strength and failure behavior of two photonic crystal silica optical fibers
with different diameters were investigated using tensile test. The effect of polymer coating on the
failure behavior was also studied. The results indicated that all fibers failed in a brittle manner and
the failure normally initiated from fiber surfaces. The failure loads observed in the coated fibers are
higher than that in bare fibers and the reason is explained by the apparent delamination between the
fiber and the polymer coating when loaded on the fiber surfaces. The relationship between a
characteristic parameter measured on the fracture surfaces and the failure stress was examined.
In Situ Measurement of Lattice Spacing of Ternary Ni-Ti-Nb Alloys during Hydrogen Absorption
Authors: Shibano Junichi , Yamamoto Yasutaka , Kobayashi Michiaki , Ishikawa Kazuhiro , Aoki Kiyoshi
Published: March 2009

Microscopic deformation of each crystal of duplex phases of Ni-Ti-Nb alloy due to
hydrogen absorption was investigated by X-ray diffraction technique. Ni30Ti30Nb40 which is
hydrogen permeation alloy and consists of the primary phase, NbTi, and the eutectic phases, NiTi +
NbTi, was used as a specimen. The change of lattice spacing of the specimen during hydrogen
absorption was measured by Cu-Kα characteristic X-ray. As a result, the lattice spacing of crystal
of NbTi phase increased extremely, while that of NiTi phase increased slightly. It was pointed out
that the NbTi phase is responsible for hydrogen absorption in the Ni-Ti-Nb alloy. When hydrogen
gas was released from the specimen at high temperature, both lattice spacing returned nearly to
those of them before hydrogen absorption, and the specimen kept its original shape. Therefore, it
was confirmed that the volume expansion of crystal of the Ni-Ti-Nb alloy due to hydrogen
absorption was elastic deformation.
Stress-Assisted Atomic Migration in Thin Copper Films
Authors: Takao Hanabusa , Kusaka Kazuya , Kaneko Kenta , Sakata Osamu , Masayuki Nishida
Published: March 2009

Stress-assisted atomic migration occurs in thin films due to thermal stress development, followed
by hillock and void formation on a film surface. Relation between thermal stresses and hillock formation was
investigated on copper films with and without passivation layer. Copper films with a thickness of 10, 50 and
100 nm on oxidized silicon wafer were prepared for investigating thermal stress and hillock formation. In-situ
thermal stress observation by X-ray measurement revealed that compressive stresses develop in an early stage
of heating followed by a sudden decrease in the temperature region between 100 and 200 deg. In a cooling
stage, stresses in a film linearly changed with decreasing temperature to form a tensile residual stress state.
Surface morphology is observed by optical microscope and SEM after the heat cycle as well as at elevated
temperatures in a vacuum chamber. Dome-like swells were formed on an AlN passivation layer. Almost of all
of the swells on 100 nm thick film collapsed after the heat treatment up to 350 deg whereas the swells on 10
nm thick film had no collapse excepting a few case. Comparing with the film without passivation, the swell is
considered to be the result of atomic migration of copper film to form hillocks in the interface between copper
film and AlN passivation film during heating. Atoms are considered to migrate reversibly into the copper film
in the cooling stage, resulting to make vacant hall in the swell of AlN film and then collapse due to tensile
stress development.
The Influence of Aging Process on Microstructures and Properties of an Al-2.54Li-1.61Cu-1.23Mg-0.22Zr Alloy
Authors: Shi Qi Nian , Xiong Wei Hao , Liu Sheng Guo
Published: March 2009

The influence of aging process on microstructures and mechanical properties of a rapid
solidification Aluminum-Lithium alloy has been analyzed in this paper. The results show that the
better aging process is as follows: heating to 170oC for 4 hours and then followed by a final aging at
about 190 oC for 18 hours. A lot of fine participated second phase such as δ′ in matrix and a narrow
participation free band make alloy’s good performance.
The Influence of Pre-Annealing on Recrystallization in Heavily Cold-Rolled Nickel
Authors: Cheng Zhan , Godfrey Andrew , Zhang Yu Bin , Liu Wei , Liu Qing
Published: March 2009

Polycrystalline nickel (99.999% purity) cold-rolled to a reduction of 96% has been given
a two-step annealing treatment consisting of a pre-annealing at 180 °C or 220 °C for 2 hours,
followed by a final annealing at 300 °C for 10 minutes. The changes in microstructure and texture
during annealing have been followed using electron backscatter diffraction orientation
measurements taken on the longitudinal section of the samples. The results suggest that
pre-annealing at low temperature can enhance the formation recrystallized grains of cube
orientation. Based on an analysis of the experimental data, possible reasons for the enhancement as
a result of pre-annealing in the formation of cube orientation grains are discussed.
The Grinding Force Measure and Analysis on the Abrasive Belt Grinding to Magnesium Alloy
Authors: Huang Yun , Huang Z. , Xu Q.S. , Zhou W.
Published: March 2009

This paper describes abrasive belt grinding experiment method and studies grinding force
alternation regular pattern and feature in the grinding magnesium alloy process, at the same time the
induction is verified the grinding force linear regression pattern by survey the force effect elements
in the experiment, finally summarizes the result of the magnesium alloy grinding experiment .