bluuebunny/crossref_metadata_2025 huggingface dataset:
Monte Carlo Simulation of Stress Corrosion Cracking in Structural Metal Materials Taking Account of Surface Crack Effects
Authors: Tohgo Keiichiro , Suzuki Hiromitsu , Shimamura Yoshinobu
Published: March 2009

According to laboratory accelerated test data, stress corrosion cracking (SCC) in structural
metal materials occurs by initiation and coalescence of micro cracks, subcritical crack propagation
and multiple large crack formation or final failure under the combination of materials, stress and
corrosive environment. In this paper, a Monte Carlo simulation for the process of SCC has been
proposed based on the stochastic properties of micro crack initiation and fracture mechanics concept
for crack coalescence and propagation. The emphasis in the model is put on the influence of the
semi-elliptical surface cracks. The numerical examples for a sensitized stainless steel type 304
indicate the applicability of the present model to the prediction of the SCC behavior in real structures.
On the Stress Intensity Factor of Cracks in Residual Stress Field
Authors: Wang Liang , Li Ya Zhi , Su Hong
Published: March 2009

The use of weight function technique in fatigue crack growth subjected to external cyclic
loading and residual stress field has been questioned by several researchers in that the technique is
unable to account for the residual stress redistribution during the crack growth. In this paper a
center cracked tension specimen containing residual stresses was analyzed by finite element
method. The crack growth was simulated by releasing the nodes ahead of crack tip in stepwise and
the stress intensity factors induced by residual stresses at different crack lengths were estimated.
The results from the numerical analysis are identical to the weight function solution, which
demonstrates that the weight function technique can be used for the fatigue crack growth analysis in
residual stress field, unless the residual stress distribution is disturbed by the plastic yield.
Numerical Simulation on Rolling Contact Fatigue with Dent at Rolling Surface
Authors: Zeng Fan Fei , Niu Li Sha , Shi Hui Ji
Published: March 2009

This work has investigated the effect of spherical dent on rolling contact fatigue (RCF). A
3-D finite element simulation model of bearing rolling contact incorporating critical plane approach
has been developed to study the fatigue failure location. It was found that the fatigue failure locations
were significantly influenced by the dent. The calculation results are in good agreement with the
experimental results and comparable with the results from the published literatures in which 2-D
models were generally used.
The Evaluation of the Effects of the Maximum Stress Intensity Factor for Fatigue Crack Opening Behavior by Finite Element Analysis
Authors: Choi Hyeon Chang , Choi Hyeon Ki , Park Jun Hyub
Published: March 2009

The cyclic crack tip opening displacement is well related to fatigue crack opening
behavior. In this paper, we investigate the effect of the maximum stress intensity factor, Kmax, when
predicting fatigue crack opening behavior using the cyclic crack tip opening displacement obtained
from FEA. The commercial finite element code, ANSYS, for fatigue crack closure analysis in this
study is used. We derive the prediction formula of crack opening behavior when using the cyclic
crack tip displacement obtained from the FEA. The numerical prediction shows the good results
regardless of stress ratios. It is confirmed that the crack opening behavior depends upon the
maximum stress intensity factor Kmax.
Experimental Study on Forming Underground Space in Soil Using Explosive Lining Method
Authors: Yu Qi Wu Peng shao , Wang Dong Quan , Liu Chun Rong , Zhu Yu Xiao
Published: March 2009

Explosive lining is a new method to construct underground space in soil. By making the
most of compressibility of soil and thixotropy of concrete under explosive loading, this method offers
an efficient path to form a cavity and its concrete support layer synchronously. In order to investigate
the forming effect, a series of contrastive laboratory tests, including explosive lining method and
conventional explosive compaction method, were performed under same soil and explosive
conditions. Results show that measured dynamic stress and displacement by explosive lining method
are higher than that of by conventional explosive compaction method under same equivalent radius,
and the range of compact region in soil is larger too. Similarly, the physical and mechanical
performance indexes of soil, such as water content and cohesion are superior to that of by
conventional explosive compaction. It is approved that an even thickness concrete support layer can
be formed in one-shot forming process by explosive lining, and there is no evident cranny region in
the soil around the cavity.
Damage Analysis of Medium Carbon Steel in Low Cycle Fatigue
Authors: Rui Zhi Yuan , Lu Chun Peng , Li Emin , Jin Wu Yin
Published: March 2009

By the test of rotational bending for bar of 45 steel with V notch in low cycle fatigue, the
bar’s fatigue life is studied under strain-controlled condition. The characteristics of several kinds of
specimens' crack propagations are analyzed. The accumulative effect of crack propagation is
discussed to find the appropriate load for quick fracture. Based on the theory of continuum medium
damage mechanics, the damage evolution model in low cycle fatigue is obtained. The predicted
curves and strain-life curves agree with experimental data for medium carbon steel well in this work.
These results are very important for the life estimation of medium carbon steel.
Calculation and Analysis on the Thermal Damage at High Temperature
Authors: Tang Song Hua , Luo Ying She , Ning Ming Zhe , Wang Zhi Chao
Published: March 2009

In fire resistant design traditional method based on experiment is being replaced by method
based on calculation.in this paper Damage mechanics is applied to calculate and analyze the process
of damage and failure of structures at high temperature through solving jointly the closed equations
composed of the thermal damage evolving equation based on the residual strength, heat conduction
equations, equilibrium equations, geometry equations and physics equations. An example of a truss is
given to illustrate the calculation of thermal damages and stresses at high temperature. The results
suggest, the bearing capacity at high temperature is influenced by these three main factors: thermal
damage resulted from the elevated temperature, the thermal stresses and the original load. This
provides a new research method for the modern fire-resistant design based on calculation and can be
developed and applied in the numerical simulation of the process of damage and failure of the
integrated structures.
The Fracture Mechanism of As-Cast and Extruded SiCp/AZ91 Composites Fabricated by Stir Casting
Authors: Wang Xiao Jun , Wu Kun , Zheng Ming Yi , Zhang Hai Feng , Huang Wen Xian , Hu Xiao Shi
Published: March 2009

The fracture mechanisms of SiCp/AZ91 composites were investigated by scanning
electron microscopy (SEM). For the as-cast composites, the decohesion at SiCp/matrix interface is
the main fracture mechanism because of the high stress concentration resulting from the segregation
of particles in grain boundaries formed during solidification process. But for the extruded
composites, the main fracture mechanism is the particle crack or ductile rupture of the matrix
between the particles. So the fracture mechanism of SiCp/AZ91 composites is altered by extrusion
because the segregation of particles and defects in the grain boundaries are largely eliminated by
extrusion.
Development of a New Kind of Sealing Composite Material Reinforced with Aramid and Pre-Oxidized Fibers
Authors: Gu Bo Qin , Chen Ye
Published: March 2009

A new kind of sealing composite material reinforced mainly with aramid and
pre-oxidized fibers were developed by molding preparation method. The effect of different surface
treatment methods of the fibers on the heat resistance of the composite material was studied. The
optimum prescription of the sealing composite material was obtained by regression design method.
The relationship between the transverse tensile strength of the material after ageing at elevated
temperatures and its main ingredients was investigated. The performances of the developed sealing
composite material were tested, and the results indicate that the main performances of the material
coincide with the requirements prescribed in Chinese national standard and some performances are
even better than that of the products of some famous corporations.
Effect of Mg-Based Spherical Quasicrystals on Microstructure and Mechanical Properties of ZA85 Alloy
Authors: Zhang Jin Shan , Pei Li Xia , Tian Ai Huan , Wang Xiao Ming , Lu Bin Feng , Xu Chun Xiang , Liang Wei
Published: March 2009

To improve the strength-toughness and heat-resistance of die cast magnesium alloy, the
ZA85 alloy has been prepared by adding proper amount of spherical quasicrystals containing master
alloy. The results indicate that the solidification microstructure is inlaid with quasicrystal particles,
which is a new phase i(Mg45Zn47Y5Mn3), co-existing with the α-Mg, Φ(Al2Mg5Zn2) phase and
τ(Mg32(AlZn)49) phase. Mechanical properties of ZA85 alloys have been dramatically improved
owing to the obvious grain refinement of the matrix microstructure. While adding 1.7 wt %
spherical quasicrystal containing master alloy, macro-hardness of ZA85 magnesium alloy reaches
75HB; meanwhile, impact toughness reaches the peak value 18.4Jcm-2, which is about 202% of
ZA85 base alloy. Due to the pinning effect of quasicrystal particles on grain boundaries, the
strengthened ZA85 alloys would have excellent heat-resistance.
Analysis and Design of Curved Laminated Composite Panels under External Pressure
Authors: Narita Daisuke , Narita Yoshihiro
Published: March 2009

Curved panels can bear more lateral load than flat plates because they can transmit the
external load along curved surface in addition to load-carrying capacity by the bending stiffness. For
curved panels, however, there is a critical point of the lateral load that structure can endure before it
buckles. On the other hand, composites are known to have more advantages in specific strength and
stiffness than conventional metal materials. The present paper proposes a semi-analytical method to
predict the initial buckling loads of slightly curved panels composed of thin orthotropic composite
layers under general boundary conditions. Based on the Donnell type theory, the potential strain
energy is evaluated as a sum of stretching energy, stretching-bending coupling energy and bending
energy, and the external work done by uniform external pressure is included in the functional. The
eigenvalue equation is derived by the Ritz method to yield such initial buckling load parameters as
eigenvalues. Numerical examples include a list of buckling loads and the corresponding buckling
patterns for typical panels with simply supported and clamped edges.
Investigation on the Primary Si Phase Solidification and the Properties of SiCw/Al-18Si Composites
Authors: Geng Lin , Wei Hong Mei , Zhang Xue Xi
Published: March 2009

SiCw/Al-18Si composites were prepared by squeeze casting technique. SiCw/Al-18Si
composites were remelted before solidification. The effects of volume fraction of SiC whisker on
solidification behavior of SiCw/Al-18Si composites were investigated by means of differential
scanning calorimetry (DSC) technique and microstructure observation. DSC results indicated that the
start solidification temperature and primary silicon peak temperature decreased gradually and the
degree of supercooling increased with the increasing of SiC whisker content. SiC whisker and Sr
decreased the average size of Si phases and improved the mechanical properties of the composites.
Measurement of Delamination Strength of Thermal Barrier Coating at High Temperature by Edge-Indent Test
Authors: Nakasa Keijiro , Kato Masahiko , Zhang Bo , Akitake Noriyuki
Published: March 2009

Thermal barrier coating (TBC) was carried out on Ni based super-alloy specimens, and edge
indent tests were carried out at 1073K under different displacement rate. In addition, the specimens were
heated and held at 1273K for long time, and the edge-indent tests of the specimens were performed both
at 1273K and at room temperature. The results showed that the delamination load Pd and the
delamination energy Ed measured at 1073K after short time holding were larger than those measured at
room temperature, and the Pd and Ed slightly decreased with increasing displacement rate at 1073K while
they slightly increased at 293K. The Pd and Ed at 1273K increased with increasing holding time and
reached a maximum at 1400ks. With further increase in holding time, the Pd and Ed largely decreased.
The Pd and Ed measured at 1273K were smaller than those at room temperature.
Biodegradable Composites Based on Polylactic Acid (PLA) and China Jute Fiber
Authors: Hu Rui Hua , Lim Jae Kyoo , Kim Chul In , Yoon Ho Chel
Published: March 2009

There is an increasing interest in developing fully biodegradable materials for industrial
applications. Composite combining biodegradable polymer and natural fiber could be a fully
biodegradable material. This work focus on the investigation on China jute fiber reinforced PLA
composites. Composites with three different fiber volume fractions were fabricated by film stacking
hot press method. Mechanical properties have been investigated and the microstructure of the
composites was observed. Fiber surface treatment by silane was applied in order to investigate the
effects on the properties of the composites. The moisture absorption rates in a hygrothermal
environment were also measured.
Free Vibration of Composite Annular Plates Embedded with SMA Fibers in the Circumferential Direction
Authors: Li Shi Rong , Yu Wen Shan , Fan Liang Liang
Published: March 2009

Based on Brinson’s one-dimensional thermo-constitutive law of SMA and classical plate
theory, linear non-axisymmetric vibration of uniform heated composite annular plate embedded
with circumferential SMA fibers is investigated. Natural frequencies of the annular plates with
immovably clamped boundary condition, depending on the temperature rise are obtained by using
shooting method. The characteristic curves of first four natural frequencies of non-axisymmetric
vibration versus temperature rise are plotted. Influences of the volume fraction and the initial strain
of SMA on the natural frequencies of plate are analyzed. The numerical results show that, the
activation of SMA can enhance the natural frequency both in the inverse martensite transformation
temperature range and the thermal buckling temperature.
Formation of Cf/C Composites with SiC Concentration Gradient on the Surface by SHCLD Technique
Authors: Chen Guang Li , Geng Hao Ran , Chen Jun Hua , Li Hui , Guo Zhong Quan
Published: March 2009

Adopting two-step deposition processes, SiC concentration gradient layer on the surface
of Cf/C composites were prepared via Self-heating Chemical Liquid Deposition (SHRCLD)
technique. In second deposition process, carbon and SiC were codepositted from pure kerosene and
TEOS. The temperature of deposition was 1000°C~1200°C and the system pressure was 0.1MPa.
Different thickness of gradient layers would be attained via adjusting the proportion of TEOS in
procurer and controlling deposition time. Oxidation resistance, and mechanical tests were
investigated, and the microstructure was observed under SEM. Results showed that the flexural
strength of the composites was 123.7 MPa. The antioxidation temperature of Cf/C composites with
the gradient layer is up to 800°C in air. The process of SHCLD technique is simple and easy to be
controlled, and the deposition rate is faster than other conventional technique.
Time-Temperature-Stress Equivalence Applied to Accelerated Characterization of Creep Behavior of Viscoelastic Polymer
Authors: Zhao Rong Guo , Luo Wen Bo , Wang Chu Hong , Tang Xin
Published: March 2009

Temperature induced change, and stress induced change as well, in intrinsic timescale
were investigated by nonlinear creep tests on poly(methyl methacrylate). With four different
experimental temperatures, from 14 to 26 degrees centigrade, time-dependent axial elongations of
the specimen were measured at seven different stress levels, from 14 MPa to 30 MPa, and modeled
according to the concept of time-temperature-stress equivalence. The test duration was only 4000
seconds. The corresponding temperature shift factors, stress shift factors and temperature-stress
shift factors were obtained according to the time-temperature superposition principle (TTSP), the
time-stress superposition principle (TSSP) and the time-temperature-stress superposition principle
(TTSSP). The master creep compliance curve up to about two-year at a reference temperature 14
degrees centigrade and a reference stress 14 MPa was constructed by shifting the creep curves
horizontally along the logarithmic time axis using shift factors. It is shown that TTSSP provides an
effective accelerated test technique in the laboratory, the results obtained from a short-term creep
test of PMMA specimen at high temperature and stress level can be used to construct the master
creep compliance curve for prediction of the long-term mechanical properties at relatively lower
temperature and stress level.
Modeling and Testing Strain Rate-Dependent Tensile Strength of Carbon/Epoxy Composites
Authors: Zhao Gui Ping , Wang Zheng Hao , Zhang Jian Xin , Huang Qiao Ping
Published: March 2009

Tensile strength is an important material property and usually can be determined
experimentally. The strain rate dependent behavior of T300 carbon/epoxy matrix composite was
characterized over a wide strain rate range (10×10-5 s-1to10×104s-1). The low to moderate strain rate
experiments were carried out on a MTS machine, while the high strain rate experiment was
conducted with a split Hopkinson tensile bar. A rate dependent model was introduced to simulate
the material response. Two kinds of stacking sequence of composite specimens [(45/-45)4]s and
[(0/45/90/-45)2]s were tested at different strain rates, and the results were used to determine
parameters of the model. The predictions of the model showed to agree fairly well with the
experimental results. The tensile strength and initial elastic modulus of the composites increase
when the strain rate increases.
Diagnostic Method for Delamination Monitoring of CFRP Plate Using Kriging Interpolation Method
Authors: Iwasaki Atsushi , Todoroki Akira , Izumi Satoshi , Sakai Shinsuke
Published: March 2009

The present paper proposes a new diagnostic tool for the structural health monitoring that
employs a Kriging Interpolation. Structural health monitoring is a noticeable technology for aged civil
structures. Most of the structural health monitoring systems adopts parametric method based on
modeling or non-parametric method such as artificial neural networks or response surfaces. The
conventional methods require FEM modeling of structure or a regression model. This modeling needs
judgment of human, and it requires much costs. The present method does not require the process of
modeling, in order to identify the damage level using the discriminant analysis. This suggest us, this
technique is applicable to the health monitoring system, which identifies the damage of the structure,
easily. In the present paper, we developed the damage diagnostic methods using Kriging method for
identifying delamination from data. Kriging method is a interpolation technique which shown in
geostatistic. We applied this method to identifications of delamination crack of CFRP structure.
Delamination cracks are invisible and cause decrease of compression strength of laminated composites.
Therefore, health-monitoring system is required for CFRP laminates. The present study adopts an
electric potential method for health monitoring of graphite/epoxy laminated composites. The electric
potential method does not cause strength reduction and can be applied existing structures by low cost.
As a result, it was shown that this method is effective for identification of damages.
Synthesis and Magnetic Properties of Polymer Derived Metal/SiCN Ceramic Composites
Authors: Yan Xue , Cheng Xiao Nong , Han Guang Cai , Hauser Ralf , Riedel Ralf
Published: March 2009

Metal particles were embedded in a silicon carbonitride (SiCN) matrix, derived from the
commercially available polysilazane Ceraset®. Metal powders, such as Fe, Mn, Co, Ni, were mixed
and milled with pre-cross-linked polysilazane and subsequent pyrolysis. The metals act as active
fillers to increase the density of composite. The phases and microstructures of metal/ceramic
composites were studied using XRD, SEM and EDS. The magnetic property was measured with
Magnetic Property Measurement System at –196oC and 27oC. The results show that there were two
main domains in composites, one was metal-rich domain and another was metal-poor domain. The
reaction compound between metal and matrix had great effect on the magnetic properties of
composites, filled with different metals.
BBPPAmorphous Si-B-C-N Ceramics Fabricated by High Energy Ball Milling and Hot Pressing
Authors: Yang Zhi Hua , Zhou Yu , Jia De Chang , Meng Qing Chang , Yu Chang Qing
Published: March 2009

Amorphous Si-B-C-N ceramics obtained by high energy ball milling and hot pressing using
hexagonal boron nitride (h-BN), graphite (C) and amorphous Si as starting materials have been
studied. The mechanical milling with high energy resulted in the generation of large amounts of
amorphous composites only milled for 5 h. Si-B-C-N powders were consolidation by hot pressing at
1850 °C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that small
amount of BN and SiC crystal lies in the amorphous matrix. The flexural strength reached the
maximal value of 137.2 MPa at a mole ratio of BN/(Si+C) being 0.6.
Internal Friction of a 2D-C/SiC Composite from 25°C to 400°C
Authors: Hou Jun Tao , Qiao Sheng Ru , Lu Guo Feng , Zhang Cheng Yu , Zhang Yue Bing
Published: March 2009

By means of forced non-resonance under 3-point bending method, the internal frictions
of 2D-C/SiC composites are carried out from 25°C to 400°C in air. The effects of temperature,
amplitude and frequency on internal frictions have been analyzed. Results show that interface layer
plays a dominant role to internal friction. When temperature increases from 25°C to 400°C, internal
friction of 2D-C/SiC composite increases slightly, and storage modulus decreases monotonically.
With frequency increases from 1Hz to 100Hz, internal friction reduces to a minimum around 10Hz,
whereas above 50Hz it arises sharply. In amplitude scale from 0.5μm to 10μm, internal friction
increases linearly with the increase of amplitude.
Effects of Notch Size on Strength Distribution of Ceramic Components
Authors: Wang Feng Hui , Wu Ying Xi
Published: March 2009

The dependence of strength on notch radii of ceramic components is presented. The
strength is exponential decay as the notch radius decrease, the smooth specimen that corresponds to
the infinity notch radius topped the fracture strength, but the lowest value relys on the micro feature
of the materials. Plotted the strengths on Weibull and Normal probability paper, the fitness
coefficients reveal that the strength of smooth specimen, as the past literatures indicated, follows
Weibull distribution, but the strength of notched specimen follows Normal distribution better. Such
result is due to the fact that the decreasing notch radius reduces and limits the effective original
fracture volume, when the notch becomes a slim crack, the weakest link place becomes
deterministic.
Fabrication and Microstructure of SrBi2Ta2O9 Ceramic
Authors: Wang Wen , Niu Hai Jun , Xian Heng Ze , Yang Jian Li , Ke Hua , Zhou Yu
Published: March 2009

In this research, SrBi2+xTa2O9 (SBT) powders with different Bi content were prepared
using conventional solid-state reaction method. The SrBi2+xTa2O9 ceramics (x=0 ,0.2 ,0.4 ,0.6)
were fabricated by the cold isostatic compaction and sintering in the air. Microstructure and dielectric,
ferroelectric properties of SBT ceramics were investigated by XRD, SEM, EDAX and dielectric
tester. The effects of Bi content on dielectric, ferroelectrc properties in SBT ceramics were discussed.
Study on Pressure Variations in the Mold of Magnesium Alloy Die Castings
Authors: Liu Yan Gai , Huang Zhao Hui , Ding Hao , Fang Ming Hao , Xiong Shou Mei
Published: March 2009

High pressure die casting is the most common method in making magnesium alloys for
both auto parts and 3C products. Pressure variations in the mold during mold filling and
solidification process have direct influences on the quality and properties of die castings. In this
paper, a cylinder head cover was produced to experimentally study pressure variations in the mold
during magnesium alloy die-casting process in real time for the first time. Pressure varies at
different positions in the mold during die casting process. This study indicates that mold filling and
solidification process of magnesium alloy die castings can be described by pressure curves obtained
by pressure measurement at different test positions in the cavity in real time.
High Dense Compressive Residual Stress Produced in Laser Shock Processing on Ti6Al4V Alloys
Authors: Ren Xu Dong , Zhang Yong Kang , Zhou Jian Zhong , Gu Yong Yu , Xu Y.Y. , Zhang Xing Quan
Published: March 2009

Laser shock processing (LSP) employs high-energy laser pulses from a solid-state laser
system to create intense shock waves into a material, which can induce compressive residual stresses
in the target surface and improve its mechanical property efficiency. Residual stress of Ti6Al4V alloy
both before and after LSP with multishocks was analysised. The depth of compressive residual stress
was found to have a dependence on the number of shocking layers and a slight dependence on the
level of irradiance. Surface stress improvements of more than 50% increases are possible after laser
shock processing with either large spot or small spot patterns. The large spot gave a surface stress of
432MPa and a depth of over 1mm. The low intensity small spot gave a surface stress of 285MPa with
a depth comparable to the large spot. Laser shock processing induces a compressive residual stress
field, which increases fatigue crack initiation life and reduces fatigue crack growth rate.
Nickel Silicides Synthesized by High Energy Ball Milling
Authors: Ji Gen Shun , Ma Qin , Guo Tie Ming , Zhou Qi , Jia Jian Gang , Guo Xin , Chen Xue Ding
Published: March 2009

The high energy ball milling of Ni-50 atom % Si elemental powder mixtures was carried
out using a planetary mill. X-ray diffraction (XRD) was used to identify the phase evolutions during
the high energy ball milling period. The microstructure morphology of the powders milled different
time was determined by field emission scanning electron microscope (FESEM). The beginning time
of mechanical alloying was determined by back scattered electrons (BSE) images. The XRD
patterns showed that the nickel peaks intensity and the silicon peaks intensity obviously decreased
with milling time increased to 1 hour. BSE images revealed that nickel and silicon powders were
not blended uniformly for 1 hour of milling. It was found that NiSi formed as the milling time
increased to 5 hours, simultaneously, the nickel peaks and the silicon peaks almost disappeared.
That means the obvious mechanical alloying started from 5 hours of milling. BSE images agreed
with the result analyzed from XRD patterns. With the milling time further increased from 10 to 75
hours, the NiSi peaks decreased gradually, at the same time, the Ni2Si peaks appeared and then
increased gradually.
Tensile Properties and Fatigue Strength of Ultrafine Grained Pure Copper
Authors: Goto Masahiro , Han S.Z. , Kim Sang Shik , Kawagoishi Norio , Lim Cha Yong
Published: March 2009

Oxygen-free copper was processed by equal channel angular pressing with different
numbers of ECAP process cycles, NP. Tensile strength was increased with an increase in NP, but it
tended to saturate after NP = 4. Conversely, elongation was dramatically decreased by first pressing,
but it tended to saturate up to NP = 3, followed by slight increasing trend after NP = 4. Fatigue tests of
specimens processed with NP = 4 and 8 were performed. The change in surface morphologies during
fatigue was monitored successively. In addition to this, the change in surface hardness was measured.
Significant decrease in surface hardness due to cyclic stresses was measured. The physical basis of
fatigue damage of UFG copper was discussed based on the experimental results.
Mechanical Properties and Microstructures of Ferritic-Rolled Ultra-Low Carbon (ULC) and Ti-Stabilized Interstitial-Free (Ti-IF) Steels
Authors: Han Fu Tao , Wang Zuo Cheng , Jing Cai Nian , Zhang Wen Ping
Published: March 2009

In this paper, effects of ferritic rolling process on microstructures and mechanical
properties especially drawability of ultra-low carbon (ULC) and Ti-stabilized interstitial-free (Ti-IF)
steels were investigated and the precipitates of ferritic-rolled Ti-IF steels were also analyzed. The
results show that good deep drawability are achieved as IF steels are ferritic rolled in good lubricant
condition; on the contrary, lubricant condition has less influence on the deep drawability of ULC
steels. And with the decrease of rolling temperature in ferrite region, deep drawability of Ti-IF steels
are improved, but for ULC steels, when ferritic rolled at low temperature, the r-value is still less than
one, which means insignificant deep drawability.
Influence of Ceria on Characterization of Films Prepared by Vapor Deposition of Quasicrystal
Authors: Zhou Xi Ying , Xu Zhou , Mi Yi Ming , He Liang
Published: March 2009

Films were prepared on the steel (Q235) by means of vacuum vapor deposition through
Al65Cu20Fe15 quasicrystal powders. Influence of ceria on the microstructure and properties of films
were studied. TEM, SEM and XRD were used to observe the microstructure and morphology of
films. The hardness and the modulus of the film were tested by MTS. The results showed that the
films were formed through directly vapor deposited by Al65Cu20Fe15 quasicrystal. The films were
constituted of many phases such as CuAl2, AlCu3 and I (Al65Cu20Fe15) phase. The composition of
films was decided by the technology of deposition. After adding cerium, the microstructure of films
did not radically change, however the hardness and modulus of films varied with the increase of
cerium. When the cerium content was 5 wt%, the hardness of films was more than 9.0 GPa.
Furthermore, adding cerium could improve obviously the corrosion resistance of films.
Research on High Temperature Anti-Abrasion Protection Technology of Thermocouple Cannula
Authors: Sun Hong Fei , Wang Can Ming , Song Qiang , Yan Qiong Qiong
Published: March 2009

Abrasion mechanism of thermocouple cannula is studied in this article. For different
working position and condition, different material should be selected to ensure the working
characteristics of thermocouple cannula. Several protection methods were introduced to prolong the
sevice life of thermocouple cannula. 1. M-Al series intermetallic compound coating protection
method. 2. Metal/ceramic compound coating protection method. 3. Development of new
abrasion-resisting material for high temperature according to some special work conditions of
thermocouple cannula. With the adoption of those new technologies, thermocouple cannula’s
service life can be prolonged to 3~5 times of that untreated.
Oxidation Resistance of Ti-6Al-4V by Plasma Niobium Surface Alloying
Authors: Wang Wen Bo , Xu Zhong , He Zhi Yong , Wang Zhen Xia , Zhang Ping Ze
Published: March 2009

A niobium modified layer on Ti-6Al-4V surface was obtained by means of the plasma
surface alloying technique. The oxidation behavior of the modified layer was investigated and
compared with Ti-6Al-4V at 700°C~900°C for 100h. Composition and microstructure of Ti-6Al-4V
and the modified layer after oxidation at 900°C for 100h were analyzed using XRD and SEM
respectively. The experimental results showed the oxidation behavior of Ti-6Al-4V at 900°C for
100h was obviously improved after the niobium alloying process.
The Processing of Anti-Rust Boronizing Layer on Steel Surface
Authors: Wang Xiu Chun , Li Mu Sen , Pan Xi Qing , Sun Rui Xue , Li Yuan Jie
Published: March 2009

This paper dealt with the processing of anti-rust boronizing layer on steel surface and
phosphating as post-treatment to improve the corrosion resistance of the boronized layer. A smooth
protective layer with black brightness on the surface of the boronizing layer was obtained. The
appearance of the boronized work pieces was greatly improved. The technical parameters of the
black phosphating solution were optimized by the experiments and the microstructure and the
inoxidizability of the black phosphated coating was also analyzed.
Effect of R.F. Power on Structures and Properties of Amorphous Fluorinated Carbon Films Prepared by PSII
Authors: Tang Guang Ze , Ma Xin Xin , Sun Ming Ren
Published: March 2009

Fluorinated amorphous carbon films (a-C:H:F) were deposited by plasma source ion
implantation (PSII) with precursor gas of CH2FCF3 + C2H2 + H2 with various radio frequency (r.f.)
power. Structures and properties evolution varied with r.f. power was discussed in detail. X-ray
photoelectron spectroscopy (XPS), Raman spectrum, X-Ray reflection(XRR), atomic force
microscopy (AFM) were used to analyze composition, chemical state, sp2 cluster structure, density
and surface morphology of prepared films. Nano-indentation test was used to get hardness and
modulus. The results show that with the increase of r.f. power, the size and amount of sp2 cluster
increase, so does the surface roughness; however, the density and the hardness of films decrease.
Study of Delamination of Thin Film Coating on Cyclic Nano-Indentation Test
Authors: Kozuki Kentaro , Omiya Masaki , Kishimoto Kikuo , Inoue Hirotsugu
Published: March 2009

The aim of this paper is to evaluate the cyclic interfacial strength between thin film and its
substrate by cyclic nano-indentation tests. The specimen used in this study is PET substrate/ITO
coatings layered specimen. From the indentation load and displacement curve, we proposed an
evaluation method for the interfacial strength. The results are good agreement with the interfacial
strength evaluated by peel test. After cyclic indentations, the surface profile was observed by atomic
force microscope. The number of elongates increased with indentation cycles when the indentation
load is low, whereas elongates number is almost constant under high load cases. These phenomena
can be explained by simple models. In this study, two types of fracture modes are proposed. They are
“subsidiary fracture mode” and “buckling mode”.
Surface Morphology, Crystal Orientation and Scratch Properties of Au/NiCr/Ta Multi-Layered Metallic Films
Authors: Tang Wu , Deng Long Jiang , Xu Ke Wei , Lu Jian
Published: March 2009

The crystal orientation, surface morphology, surface roughness and scratch properties of
Au/NiCr/Ta multi-layered metallic films was examined by X-ray diffraction (XRD), atomic force
microscopy (AFM) and a scratch test method, respectively. It was clarified that the surface
morphology and surface roughness depend on the substrate temperature. The surface roughness
decreases from 4.259nm to 2.935nm when substrate temperature changed from 100°C to 180°C,
and then increases when substrate temperature above 180°C. The XRD revealed that there are only
Au diffraction peaks with highly textured having a Au-(111) or a mixture of Au-(111) and Au-(200)
orientation. The micro-scratch test reveals that both modes can be used for conventionally critical
load determination, but the friction mode can additionally reflect the changes at different metallic
film layers, the critical characteristic load was not sensitive to substrate temperature.
The Fatigue Life Prediction of Multidirectional Laminated Composites
Authors: Yin Jian , Li Ya Zhi , Zhang Pei Xin , Zhang Kai Da
Published: March 2009

A fatigue analysis method was developed to predict the fatigue behavior of the
T300/QY8911 multidirectional laminated composites. The finite element analysis of the
interlaminar stresses and the average of them localized to the free edges of the specimens were
made for predicting the delamination onsets and lives. The residual lives to failure after
delamination was estimated afterwards. The predicted fatigue lives agree well with the test results.
Application of Twin Laser Beam on AZ31/A5052 Dissimilar Metals Welding
Authors: Miyashita Yukio , Borrisutthekul Rattana , Chen Jian , Mutoh Yoshiharu
Published: March 2009

Effect of the applying twin laser beam on the welding of AZ31 / A5052 dissimilar metals
lap joint was studied. The direct welding and the welding with Al12Si filler wire were carried out.
Flow behavior of the molten metal was analyzed by FEM simulation. For both welding methods,
failure load of the joints increased by applying twin laser beam with reasonable beam distance. Twin
laser beam technique could control temperature distribution and flow behavior of the molten metal.
Method of Lines to Solve 2-D Steady Temperature Field of FGM
Authors: Tan Wei , Sun Chang Qing , Xue Chun Fang , Dai Yao
Published: March 2009

Method of Lines (MOLs) is introduced to solve 2-Dimension steady temperature field of
functionally graded materials (FGMs). The main idea of the method is to semi–discretized the
governing equation of thermal transfer problem into a system of ordinary differential equations
(ODEs) defined on discrete lines by means of the finite difference method. The temperature field of
FGM can be obtained by solving the ODEs with functions of thermal properties. As numerical
examples, six kinds of material thermal conductivity functions, i.e. three kinds of polynomial
functions, an exponent function, a logarithmic function, and a sine function are selected to simulate
spatial thermal conductivity profile in FGMs respectively. The steady-state temperature fields of
2-D thermal transfer problem are analyzed by the MOLs. Numerical results show that different
material thermal conductivity function has obvious different effect on the temperature field.
Cracking Resistance of Cu-Bearing Age-Hardening Steel
Authors: Feng Chai , Yang Cai Fu , Hang Su , Zhang Yong Quan , Zhou Xu
Published: March 2009

In this paper, the weldablity of a low-carbon Cu-bearing age-hardening steel was
evaluated using Y-groove cracking evaluation test. The results show that the steel has a low
hardenability characteristic and cold-cracking susceptibility. It is also indicated that a crack-free
weldment can be obtained during welding of this type of steel even at an ambient temperature as
low as -5°C as well as in an absolute humidity lower than 4000Pa without any preheat treatment. A
slight preheat treatment can prevent the joint from cracking when welding is carried out at lower
ambient temperature or in higher absolute humidity.
Crack Growth Characteristics of Pure Copper for Smart Stress Memory Patch
Authors: Nambu Shoichi , Enoki Manabu
Published: March 2009

A new sensing method called “smart stress memory patch”, which could estimate the
maximum stress, the stress amplitude and the fatigue cyclic number simultaneously using Kaiser
effect of Acoustic Emission (AE) and crack length of this patch, was developed. In this study, the
crack growth characteristics of this patch was evaluated. Pure copper was used for this patch because
its good corrosion resistance, stable crack propagation and so on. Two kinds of samples which were
rolled and electrodeposited copper were prepared to investigate the effect of microstructure on crack
growth behavior. Fatigue test was performed under constant stress amplitude to evaluate the crack
growth behavior using the relationship between stress intensity factor range and crack propagation
rate. The scattering in fatigue crack growth was also investigated to obtain the relationship between
crack length and the fatigue cyclic number including two-sided 95% confidence interval. The effect of
thickness and grain size on the scattering was discussed. Finally, good crack growth behavior was
obtained and the fatigue cyclic number could be estimated by this patch.
A Representative Stress Model Removing Weld Joint Type Dependency of S-N Curve
Authors: Nam Yong Yun , Han Seung Ho , Han Jeong Woo , Shin Byung Chun
Published: March 2009

The hot spot stress or the notch strain alleviates the welding detail dependency of S-N
curve to some extent. This paper suggests a new stress model which alleviates the dependency further,
thus the fatigue strengths of several welding details of same material can be evaluated with the S-N
curve of the base material. A stress at the hot spot of a weld joint is decomposed into two components;
linear rising one, and rapid rising one which is inversely proportional to the distance from the hot spot.
For the stress decomposition, a formula is proposed with which the configuration of stress
distribution near a hot spot is fitted exactly. The new stress model makes use of a geometric
characteristic of the stress distribution curve by the formula. The stress model is applied to five
different weld joints. As the result, the experimental fatigue data are plotted very closely to the S-N
curve of the base material
Fatigue Strength Evaluation of Load-Carrying Fillet Weldments under Out-of-Plane Bending Load Using Structural Stress Method
Authors: Kim Myung Hyun , Kang Sung Won , Ha Chung In , Lee Jae Myung , Kim Jeong Hwan , Na Sung Soo
Published: March 2009

Two types of load carrying fillet weldment, which are typical weld joints in ship structures, were
examined under out-of-plane bending load by using structural stress approach. Finite element analyses using
both solid and shell elements models have been performed for the assessment of fatigue strength. Basis for
the derivation of structural stress method is discussed in detail. The calculated structural stress values for the
fatigue strength evaluation of load carrying fillet weldments are independent of mesh size. In this study,
drawbacks and doubts associated with applying the structural method such as the guidance of virtual node
method and the application of three-dimensional equilibrium condition for solid model have been discussed
accompanied by various case studies. In order to solve the problem of the solid model, the alternative method
for solid model by using the equilibrium condition of the nodal force has been introduced.
Effect of Residual Stress and Weld Metal on Hysteretic Behavior of a Welded Tubular T-Joint
Authors: Jang Gab Chul , Chang Kyong Ho , Lee Chin Hyung
Published: March 2009

During the welding process to make welded joints, residual stress is inevitably generated
and weld metal is used. Welding Residual stress is influenced on the behavior of welded joints under
monotonic and cyclic loading. And the weld metals used in welding process have different
mechanical characteristics than structural steels. Therefore, to accurately predict the hysteretic
behavior of welded joints, the effect of residual stress and weld metal must be investigated.
In this paper, the residual stress distribution in a welded tubular T-joint was investigated by
carrying out three-dimensional non-steady heat conduction analysis and three-dimensional thermal
elastic-plastic analysis. To consider a effect of base metal(SM490) and weld metal(E71T-1), a cyclic
plasticity model was formulated based on monotonic and cyclic loading tests. And the formulated
model was applied to three-dimensional elastic-plastic finite element analysis. The effect of residual
stress and weld metal on hysteretic behavior of a welded tubular T-joint was investigated by carrying
out numerical analyses considering residual stress and cyclic plasticity model of base metal and weld
metal respectively.
Effects of the Welding Residual Stress on the Grounding Damage Analysis of a Tanker
Authors: Lee Tak Kee , Rim Chae Whan , Han Dae Suk , Kim B.H.
Published: March 2009

Vessels are rarely subjected to accidental loads such as the collision, grounding and
stranding. But these accidental loads cause a lot of damages to hull structure including a large
deformation, fracture, tearing and so on. In case of carrying dangerous goods such as crude oil, these
accidents can induce a serious environmental pollution. All ocean-going vessels were made by
welding. The welding residual stress is a significant shortcoming of welding remains at the hull
structure, even though welding technology in shipbuilding field has provided a variety of advantages,
e.g. remarkable shortening of the shipbuilding time. The aim of this paper is to investigate the effects
of the residual stress in a grounding accident. When a ship runs aground against a sea-obstacle like a
rock, this accident can be classified as a grounding. Among parameters of grounding accident
scenarios such as the ship speed, the initial striking point, and loading conditions of the ship, only ship
speed varies from 10 to 15 knots under ballast condition with/without consideration of residual
stress(this sentence is not clear to the read). The initial striking point is at the bow of the center line of
ship. A series of nonlinear numerical simulations with large deformation and fracture were carried out
using LS-DYNA. As a result, two cases with residual stress have longer damage length. The
difference seems to be relatively small, but not negligible.
SEM In Situ Investigation of the Effects of Ca and Sr Additions on Cracking in Cast AZ91D Alloys at Different Temperatures
Authors: Wang Xi Shu , Tang Bin , Chen Jun
Published: March 2009

We studied the effects of the Ca and Sr additions on the microstructure and the cracking
process of magnesium alloys with in-situ scanning electron microscope (SEM) images. We found
that the Ca addition is not only able to refine the Mg17Al12 phase but also form a new Al2Ca phase,
which lead to improved ductile of cast magnesium alloys at elevated temperature. The MgAlCaSr
phase can be improved the hot resistance. However, the number of cracks per unit area increases
with increasing Ca addition.
Nondestructive Detection of a Crack in a Triangular Cantilever Beam Based on Frequency Measurement
Authors: Wang Fei , Zhao Xue Zeng
Published: March 2009

Triangular cantilevers are usually used as small force sensors in the transverse direction.
Analyzing the effect of a crack on transverse vibration of a triangular cantilever will be of value to
users and designers of cantilever deflection force sensors. We present a method for prediction of
location and size of a crack in a triangular cantilever beam based on measurement of the natural
frequencies in this paper. The crack is modeled as a rotational spring. The beam is treated as two
triangular beams connected by a rotational spring at the crack location. Formulae for representing
the relation between natural frequencies and the crack details are presented. To detect crack details
from experiment results, the plots of the crack stiffness versus its location for any three natural
modes can be obtained through the relation equation, and the point of intersection of the three
curves gives the crack location. The crack size is then calculated using the relation between its
stiffness and size. An example to demonstrate the validity and accuracy of the method is presented.
Correlation between Crack Growth Rate and Magnetic Memory Signal of X45 Steel
Authors: Xing Hai Yan , Wang Ri Xin , Xu Min Qiang , Zhang Jia Zhong
Published: March 2009

Crack growth rate, as an important parameter, is widely applied in crack growth evaluation
and fatigue life prediction. The objective of this paper is to study crack growth rate with the metal
magnetic memory (MMM) technology which is a non-destructive testing method newly developed.
The correlation between crack growth rate da / dN and magnetic memory signal Hp(y) is
investigated through three-point bending fatigue testing. Samples of steel X45, with different heat
treatments, quenching and thermal refining, are tested in HYG fatigue machinery. The correlation
curves of da / dN ~ Hp(y) are built and the characteristics of magnetic memory signal are given. The
influence of heat treatment on Hp(y) is also analyzed. The crack growth rate model of X45 based on
MMM signal is presented and verified.