bluuebunny/crossref_metadata_2025 huggingface dataset:
Global-Local Hierarchical Analysis Techniques for Damaged Aircraft Fuselage Considering Bulging Deformation of Crack
Authors: Ju Jin San , Jiang Xiu Gen , Fu Xiang Rong
Published: March 2009

In order to calculate the fracture parameters (Stress intensity factor) in a complicated 3-
dimention aircraft model with damage in the aircraft panel, a new two steps global-local
hierarchical analysis strategy is used. This paper primarily describes the development and
application of advanced computational analysis techniques to determine stress intensity factors for
the damaged panels based on the two steps hierarchical analysis strategy from global to 3-D local
model, the bulging deformation of crack can be considered in the local model. A fracture parameter
calculation programme based on automated global-local procedure to simulate cracked aircraft
panel tests is developed for the hierarchical strategy. This programme may create models of two
stages, transfer boundary conditions, calculate and obtain fracture parameter automatically. Finally,
this paper presents some of the experimental data and the calculated fracture parameters are
compared with the experimental results.
Microstructure and Mechanical Properties of A Ultra-High Carbon Steel
Authors: Lin Wei Ping , Fan Ya Jun , Zhang Zhan Ling , Zhu Jie Wu , Liu Yong Ning
Published: March 2009

A ultrahigh carbon steels (UHCS) containing 1.6 wt pct carbon was studied. Through
spheroidizing process by divorced-eutectoid transformation (DET), the forged microstructure was
spheroidized and the microstructure was fine carbide particles distributed in ferrite matrix.
Second-time heat treatment included two kinds of technologies: normalizing and quenching +
tempering. Finally, the UHCS obtained ideal mechanical properties. The yield strength and tensile
strength of the UHCS were higher than that of 40CrNiMo, moreover plasticity of the UHCS was
equal to that of 40CrNiMo. So the UHCS was an excellent structural material.
Axial Dynamic Tensile Strength of Concrete under Static Lateral Compression
Authors: Weerheijm J.
Published: March 2009

The rate effect on concrete tensile strength can be modeled by the description of crack
extension in a fictitious fracture plane [1,2].The plane represents the initial, internal damage and the
geometry of the final fracture plane. In the paper, the same approach is applied to model the failure
envelope for the biaxial loading condition of static lateral compression and axial impact tensile
load. The predicted failure envelope is compared with data from experimental work.
Vibration Characteristics of Fatigue Crack Damage in Simplified Beam Structure
Authors: Qiang Pei , Wang Gui Xuan , Guo Xun
Published: March 2009

Free vibration characteristics of an elastic simple beam with a fatigue notch crack damage located any where of the beam is investigated. The notch crack is modeled by an elastic torsion spring whose stiffness is taken to be finite and is determined from fracture mechanic theory. On the assumption that the crack is always open when the beam vibrates transversely, the motion equation and the boundary conditions of a simple-supported beam with a crack located anywhere of the beam is deduced. The first-order to the sixth-order frequencies varying with the crack depth and the crack location are calculated.
Evaluation of Corrosion Fatigue Crack Initiation Life of 13Cr Steel
Authors: Kim Won Beom , Paik Jeom Kee , Yajima Hiroshi
Published: March 2009

In this research, corrosion fatigue crack initiation tests using 13 Cr stainless steel were
conducted in synthetic seawater to investigate the corrosion fatigue crack initiation life (Nc). In
addition, a corrosion fatigue crack initiation and propagation model was suggested also. Until now,
corrosion fatigue crack initiation life was treated ambiguously. The important point of this model is
the suggestion of the moment of the corrosion fatigue crack initiation life at which the critical size
of the corrosion pit changes to the crack. As the crack which emanates from the pit is usually small,
accordingly it is treated as a small crack. In addition, the observation of the corrosion fatigue
fracture surfaces using SEM were conducted. And the fracture mechanics analysis using an intrinsic
crack model was conducted for the treatment of the small crack. Finally, the following were
obtained. In the case without a clear stress concentration point which seems to fall into a corrosion
fatigue crack initiation, as the meaning to define the number of cycles, at which the fatigue crack
propagation rate becomes faster than the corrosion pit growth rate so that the fatigue crack initiates
from the pit and its propagation starts in earnest, as the reasonable and universal corrosion fatigue
crack initiation life (Nc) has been clarified.
The Static Collapse Characteristics of CFRP Side Members Due to Stacking Condition
Authors: Lee Kil Sung , Yang In Young
Published: March 2009

Currently, stacking condition related to the energy absorption of composite materials is
being considered as an issue for the structural efficiency and safety of automobiles, aerospace
vehicles, trains, ships even elevators during collision. In particular, CFRP (carbon fiber reinforced
plastics) composite materials have found wide applicability because of their inherent design
flexibility and improved material properties. The most important objective in designing automobiles
is currently to focus on environment-friendly aspect and safety performance aspect. Therefore, the
designing automobile should be more concerned on the aspect of securing safety performance, but
at the same time, it also should consider reducing weight of automobile structural member. In this
study, CFRP (Carbon Fiber Reinforced Plastics) side members with single-hat-section shaped were
manufactured. The axial static collapse tests were performed for the members using universal
testing machine, and the collapse mode and energy absorption characteristics were analyzed
according to stacking condition such as fiber orientation angle and shape of the section.
Effects of Residual Stress and Traction Force on the Contact Fatigue Life of Railway Wheels
Authors: Seo Jung Won , Hur Hyun Mu , Kwon Sung Tae , Choi Jae Boong , Kim Young Jin
Published: March 2009

Damage often occurs on the surface of railway wheels due to wheel-rail contact fatigue.
Since the wheel failure can cause derailment causing the loss of life and property, it should be
removed prior to the wheel failure. The effect of surface removal on contact fatigue life has been
investigated by many researchers, however, the effects of residual stress and traction force have not
been reported yet. The railway wheel reserves the initial residual stress due to the manufacturing
process, and this residual stress is changed by the thermal stress induced by braking. Also, the
traction force is usually applied along with residual stress on wheels of locomotive and electric
motor vehicle. In this study, the effect of surface removal on the contact fatigue life for a railway
wheel has been evaluated by applying the rolling contact fatigue test. Also, the effect of traction
force and change of residual stress on the contact fatigue life has been estimated by applying finite
element analysis. It is found that the residual stress is a dominant factor determining the surface
removal depth as far as the traction coefficient is less than 0.15. If the traction coefficient is greater
than 0.2, however, the surface removal depth is observed to be independent on the residual stress.
A Study on the Structural Analysis and Loading Test of the Bogie Frame
Authors: Yoon Sung Cheol , Kim Won Kyung , Kim Jeong Guk
Published: March 2009

This paper describes the results of structural analysis and loading test of a bogie frame.
The purpose of the analysis and test is to evaluate the safety and functionality of the bogie frame
under maximum load. The bogie system consist of the bogie frame, suspensions, wheel-sets, a brake
system and a transmission system. Of these components, the bogie frame is the major component
subjected to the vehicle and passenger loads. The evaluation method used the JIS E 4207
specifications throughout the FEM analysis and static load test. The test results have shown the
bogie frame to be safe and stable under design load conditions.
Effect of Surface Treatment on the Life of AISI H13 Steel Core Pin for Die-Casting
Authors: Rhyim Young Mok , Youn Kuk Tae , Na Y.S. , Lee Jong Hoon
Published: March 2009

The Effect of die surface modification on the physiochemical melt-out phenomenon was
investigated. To measure the melt-out resistance more accurately, the mean depth measurement
method after immersion in molten Al-alloy was proposed instead of the conventional weight change
method. The validity of the mean depth method was verified by the comparison with the field
service test of core-pin. The several kind of nitriding, such as gas nitriding, ion nitriding, salt-bath
nitriding and TNHT process of PHILOS TECHNOLOGIES, INC were employed to change
surface condition and their effects on melt out resistance were examined by the immersion test and
the field service test of core pins. The melt-out depth was decreased with the nitriding treatments
and in case of ion-nitrided specimen showed 2.8 times lower dissolution depth than as heat treated
specimen. The white compound layer play a important role in the prevention of physiochemical
reaction, therefore, the TNHT process, which does not form the white layer, was less effective in
the view point of melt-out phenomenon only. The field test result using core-pins for producing
automobile engine parts showed similar tendency with the mean depth method and this implies that
the mean depth method reflects the melt-out resistance of the modified surfaces effectively.
The Structural Stability Analysis of an Articulation Type Container Crane Using Wind Tunnel Test
Authors: Lee Seong Wook , Han Dong Seop , Han Geun Jo
Published: March 2009

This study was carried out to analyze the effect of wind load on the stability of an
articulation type container crane using wind tunnel testing. This was done in order to furnish
designers with data that can be used in the design of an articulation type container crane that is wind
resistant, assuming an applied wind load of 75m/s velocity. Data acquisition conditions for this
experiment were established in accordance with similarity. The scale of the articulation type
container crane model, wind speed and time were chosen as 1/200, 1/13.3 and 1/15 respectively and
this experiment was conducted using an Eiffel type atmospheric boundary-layer wind tunnel with
11.52m2 cross-sectional area. All directional drag and overturning moment coefficients were
investigated and uplift forces due to wind load at each supporting point were analyzed.
Effect of Isothermal Aging on Magnetic Properties in 12Cr Steel
Authors: Kim C.S. , Kim Il Ho , Park Ik Keun , Hyun C.Y.
Published: March 2009

The magnetic coercivity of martensitic 12Cr steel was measured in order to evaluate its
degree of isothermal aging. As the aging time increased, the lath width increased and the dislocations
were recovered. Aging resulted in the coarsening of the as-tempered carbides (M23C6 and MX)
followed by additional precipitation of Fe2W. The magnetic coercivity rapidly decreased during the
initial aging period of about 1,000 hours and then decreased slightly thereafter. The decrease in the
coercivity with increasing aging time was related to the decrease in the number of pinning sites, those
associated with the dislocations, fine precipitates and coarsening of the martensite lath/subgrain.
Topology Optimization of a Vehicle’s Hood Using Evolutionary Structural Optimization
Authors: Choi S.H. , Park J.Y. , Shin I.S. , Han Seok Young
Published: March 2009

Topology optimization of the inner reinforcement for a vehicle’s hood has been performed
by evolutionary structural optimization (ESO) method. The purpose of this study is to obtain
optimal topology of the inner reinforcement for a vehicle’s hood considering static stiffness and
natural frequency simultaneously. To do this, the multiobjective design optimization technique was
implemented. From several combinations of weighting factors, a Pareto-optimal solution was
obtained. Optimal topologies were obtained by the ESO method, i.e., by eliminating the elements
having the lowest efficiency from the structural domain. As the weighting factor of the elastic strain
efficiency goes from 1 to zero, it is found that the optimal topologies transmits from the optimal
topology of static stiffness problem to that of natural frequency problem. Therefore, it was
concluded that ESO method is effectively applied to topology optimization of the inner
reinforcement of a vehicle’s hood.
Evaluation of Defect in Compostie Using Acousto-Ultrasonic Technique
Authors: Lee Min Rae , Lee Joon Hyun
Published: March 2009

This paper is focused on the capability of the Acousto-Ultrasonic (AU) technique and the
non-contact technique to provide diagnostic information useful to detect defect in composite. An
acousto-ultrasonics (AU) is to simulate stress wave that resemble acoustic emission waves but
without disrupting the material. One launched inside the material sample, the wave are modified by
stochastic processes like those that affect spontaneous acoustic emissions from internal sources
during stressing, deformation, etc. Moreover, acousto-uloasonic waves are launched periodically at
predetermined times and with predetermined reparation rates. A fiber reinforced composite
materials should be inspected in fabrication process in order to enhance quality by prevent defects
such as delamination and void. In conventional ultrasonic technique for the evaluation of FRP, the
transducer should be contacted on FRP. Therefore, in this study, advanced conventional contacting
method (AU) and non-contact technique using air-coupled transducer can make contact and noncontacting
ultrasonic technique available in evaluation of FRP. This paper demonstrates first results
using an acousto-ultrasonic technique.
An Electromagnetic and Thermo-Mechanical Analysis of High Frequency Induction Heating for Steel Plate Bending
Authors: Lee Jang Hyun , Lee Kyung Ho , Yun Jong Sung
Published: March 2009

Eddy currents of electromagnetic field leads not only to the local heating of plate but also
to the thermal-elasto-plastic deformation in the induction heating. It is necessary to have a
simulation model to attract the possibility of induction heating equipment and to study the
deformation behavior. The goal of present paper is to investigate the possibility of induction heating
equipment for steel plate bending. The residual stress distribution of induction heating is
investigated by an electromagnetic analysis in conjunction with thermal-mechanical analysis. A
computational model based on FEA is used to study the electromagnetic field and thermalmechanical
process. Comparison with the residual strain fields and deformation of both heating
shows that the induction heating has good similarity with the gas heating.
Research on the Precipitates in Warm-Rolled Ti-Bearing Interstitial-Free Steel Sheets
Authors: Jing Cai Nian , Wang Zuo Cheng , Han Fu Tao , Zhang Wen Ping , Yi Yan Hong
Published: March 2009

Warm-rolling can save the production cost and extend the production kind of hot-rolled
IF steel strip, the precipitates strongly influence the annealing process and texture evolution so as to
the final mechanical properties of the production, very few studies has relate to the precipitates of
IF steels warm-rolled in ferrite region. In present work, two Ti- IF steels were warm-rolled in ferrite
region under different rolling parameters and the precipitates were investigated. Transmission
electron microscopy (TEM) and Energy dispersion Spectroscopy (EDS) microanalysis were carried
out on carbon extraction replicas, the characteristics such as morphology, type, amount and size of
precipitates were analyzed. The results show that different type of precipitates were appeared in two
steels, TiN, TiS, Ti4C2S2 and TiC were found in common Ti-IF steel, but in high strength Ti-IF steel,
the amount of TiS, Ti4C2S2 was very few and FeTiP precipitates appeared, the type and morphology
of precipitates were not affected by rolling parameters, however, the number and size of precipitates
were changed. Finally, the effect of different P content on the change of precipitates was analyzed,
the precipitating mechanism was also discussed.
On Creep Rupture Characteristics in STS304 Stainless Steels
Authors: Kim Seon Jin , Kong Yu Sik , Noh Young Join , Jung Won Taek , Kwon Sang Woo
Published: March 2009

In this study, the creep rupture tests of STS304 stainless steels were investigated at three
different elevated temperatures of 600, 650 and 700 under the constant creep stresses.
Creep rupture characteristics such as creep stress, creep rupture time, steady state creep rate and so
on were evaluated. The behaviors of creep rate curve and initial strain are compared at three
different elevated temperatures. The stress exponent (n) at 600, 650 and 700 based on
steady state creep rate showed 22.5, 20.6 and 11.4 respectively. By increasing the temperature, the
stress exponent is decreased. At the temperature of 700, the lowest stress exponents are shown
and this behavior is also observed in the case of stress exponent based on rupture time. The creep
life prediction by LMP method is presented and the equation of this result is as follows:
T(logtr+20)=-0.005152-14.56+24126.
Nano-Grating Fabrication Technique
Authors: Xie Hui Min , Liu Zhan Wei , Zhang Ming , Chen Peng Wan , Huang Feng Lei , Zhang Qing Ming
Published: March 2009

In this paper, a novel nano-moiré grating fabrication technique was proposed for
nanometer deformation measurement. The grating fabrication process was performed with the aid
of Atomic Force Microscope (AFM) on the basis of micro-fabrication technique. On the analysis of
some correlative factors of influencing grating line quality, some important experimental
parameters were optimized. In this study, some parallel and cross nano-gratings with frequencies of
from 10000lines/mm to 20000lines/mm were fabricated. The successful experimental results
demonstrate that the nano-grating fabrication technique is feasible and also indicated that these
nano-gratings with nano-moiré method can be applied to deformation measurement, which offers a
nanometer sensitivity and spatial resolution.
A Study on Flow Performance of Axial Inlet Cyclone for Dust Collector
Authors: Kim In Kwan , Kim J.S.
Published: March 2009

In this study, numerical analysis to develop optimal dust collector having an axial inlet
cyclone was performed for the 3 dimensional flow field with a control volume including gases and
particles. We applied FVM(Finite Volume Method) for calculating the flow distribution and the
pressure drop into the control volume using a commercial code FLUENT. The k-ε turbulence model
was used to obtain the analytical results and the major parameters were the geometrical dimension
of helical guide vanes, the inner diameter and length of cylindrical part. Particle trajectory
calculations were performed for the particle sizes of 5~75㎛ corresponding to KS A 0090. Finally
we found out and recommended one dust collector that showed appreciable performance
improvement. The experiment for confirming the numerical results was conducted by KS R 1041.
From the numerical analysis and the experimental test, it was seen that the specified collector
recommended in this study had dust collecting rate of about 99.91% and the pressure drop of
23.9mbar, and was more effective than old one that had been conventionally used in real work field.
A Study on the Cracked Specimen for Biaxial Tensile Loading Test
Authors: Shin Dong Chul , Nam Byeung Gun , Nam Jeong Hwan , Hawong Jai Sug , Watanabe Katsuhiko
Published: March 2009

In the recent years, the studies on the mechanical behaviors of various materials
subjected to biaxial loading have been worked since they are more complicated and intrinsically
different from those under the simple uniaxial condition. The cruciform specimen without any slots
has been commonly used for the goal so far. We prepare improved biaxial specimen with slots and
make sure its validity by means of finite element analysis and photoelastic experiment. Even though
the equal load biaxiality was applied to the specimens, as the results, we found that the stress
biaxiality ratios in central region of specimen differ according to the position from the center of
them, the specimen with slots in the arms is more effective to make state stress uniform than the
specimen without slot.
Flexible Force Sensors Using Fiber Bragg Grating
Authors: Heo Jin Seok , Cheung Jong Ha , Lee Jung Ju
Published: March 2009

In this paper, we present a newly designed flexible optical fiber force sensors which use
fiber Bragg gratings and diaphragm and bridge type transducer, to detect a distributed normal force
and which is the first step toward realizing a tactile sensor using optical fiber sensors (FBG). The
transducer is designed such that it is not affected by chirping and light loss to enhance the
performance of the sensors. We also present the design and fabrication process and experimental
verification of the prototype sensors.
Self-Oscillating Microcantilever Piezoresistive Flow Sensor
Authors: Go Jeung Sang , Shin Bo Sung , Ko Jong Soo
Published: March 2009

This article presents a new approach to measure the fluid velocity using the flow-induced
vibration of a microcantilever. The gas flow sensor was fabricated using the microfabrication
technology and mounted on a printed circuit board for experimental evaluation. For signal
processing, a Wheastone bridge circuit was prepared. The experimental measurement of the fluid
velocity was performed in the wind tunnel. The flow-induced vibration of the microcantilever was
firstly visualized. Based on the power spectrum analysis, the vibrating frequency was constant at
1.173 kHz, independently of the inlet velocity. It is completely different from the conventional
flow-induced vibration proportional to the inlet velocity. The peak-to-peak voltage outputs
corresponding to the air velocities of 3, 4, 5 and 6 m/s were measured.
A MEMS Position Encoder for Comb-Drive Actuators Using Suspended Gate Field-Effect Transistors
Authors: Lin Tung Wei , Hou Max Ti Kuang , Chen Rong Shun
Published: March 2009

Utilizing suspended gate field-effect transistors (SGFETs), a displacement sensing
mechanism is proposed in this paper. The design, numerical simulations, and fabrication process
of the SGFET are presented. The SGFET arrays and the comb-drive actuator are integrated to
form a MEMS position encoder. The resolution of the proposed MEMS position encoder is 6 μm
over a 54 μm travel range. By arranging the SGFETs into arrays, position feedback over a large
travel range is achieved for a comb-drive actuator.
Soft Linear Actuator Based on Dielectric Ealstomer
Authors: Choi Hyouk Ryeol , Jung Min Young , Chuc Nguyen Huu , Kim Jung Woo , Koo Ig Mo , Jung Kwang Mok , Lee Y.K. , Nam Jae Do , Koo Ja Choon
Published: March 2009

This paper presents a new design of an artificial muscle actuator called tube-spring actuator
(TSA) that is fabricated with dielectric elastomer. The new actuator construction includes two steps:
the first is that a cylindrical actuator is manufactured with dielectric elastomer with multi-layer
lamination process. Then a compressed spring is inserted to inside the tube as the second step of the
process. The inner spring is used to maximize the axial deformation while constraining the radial
contraction. This design enables effective linear actuation with largest amount strain. The monitored
strain of active length is up to 15 percents. The manufactured actuator is applied to a robot hand as an
example of the actual application.
Structural Design of Piezoelectric Actuator Considering Polarization Direction and Continuous Approximation of Material Distribution
Authors: Lim Young Seok , Min Seung Jae , Nishiwaki Shinji
Published: March 2009

In the design of piezoelectric actuator the concept of compliant mechanism combined
with piezoelectric materials has been used to magnify either geometric or mechanical advantage.
The polarization of piezoelectric materials is considered to improve actuation since the piezoelectric
polarization has influences on the performance of the actuator. The topology design of compliant
mechanism can be formulated as an optimization problem of material distribution in a fixed design
domain and continuous approximation of material distribution(CAMD) method has demonstrated
its effectiveness to prevent the numerical instabilities in topology optimization. The optimization
problem is formulated to maximize the mean transduction ratio subject to the total volume
constraints and solved using a sequential linear programming algorithm. The performance
improvement of Moonie actuator design confirms an effect of polarization direction and CAMD.
Wireless Strain Monitoring of CFRP Laminates Using Electric Resistance Change with Oscillating Circuit
Authors: Matsuzaki Roysuke , Todoroki Akira
Published: March 2009

To identify a delamination crack in a CFRP laminate wirelessly, we proposed an electric
resistance change method with oscillating circuit in the previous study. Although the method detects
the delamination creation, it cannot monitor condition of applied strain before delamination creation
because the electric resistance change due to strain changing is quite small. In the present study, a
bridge circuit, two amplifiers and voltage-controlled oscillator are added to sensing circuit so that it
can monitor very little change of the electric resistance change. Using proposed strain sensing
system, the electric resistance change and oscillating frequency change due to strain changing are
experimentally measured. As a result, the method is found to successfully monitor the applied
strain.
Identification of a Fish-Like Robot Using Inertial Sensors
Authors: Ariyanto Irfan , Kang Tae Sam , Lee Young Jae
Published: March 2009

The efficiency of fish swimming dynamics has motivated researchers to develop fish-like
robots. As a beginning step, a fish-like robot (boat) is built to simulate the fish swimming dynamics.
By using data collected from inertial sensors, a suitable mathematical model explaining fish turning
dynamics is obtained through system identification method. The identified model matches well with
the experimental results and thus can be used for the design of controllers.
Mechanical Design of Biomimetic Fish Robot Using LIPCA as Artificial Muscle
Authors: Wiguna Tedy , Heo Seok , Park Hoon Cheol , Goo Nam Seo
Published: March 2009

This paper presents a mechanical design of biomimetic fish robot using the Lightweight
Piezo-Composite Actuator (LIPCA). We have designed a mechanism for converting actuation of
the LIPCA into caudal fin movement. The linkage mechanism consists of rack-pinion and four-bar
linkage systems. Two kinds of caudal fins are fabricated such that the shapes resemble
subcarangiform and ostraciiform caudal fin shape, respectively, and then attached to the linkage
system. The swimming test using 300 Vpp input with 1 Hz to 3 Hz frequency was conducted to
investigate the effect of tail beat frequency and shape of caudal fin on the swimming speed. The
maximum swimming speed was reached when the device was operated at its natural swimming
frequency. At the natural swimming frequency of 1.016 Hz, maximum swimming speeds were
1.267 cm/s and 1.041 cm/s for ostraciiform and subcarangiform caudal fin, respectively. The
Strouhal numbers, which are a measure of thrust efficiency, were also calculated in order to
examine thrust performance of the present biomimetic fish robot.
A Carbon Nanotube Film for Power Harvesting
Authors: Kang In Pil , Choi Gyeong Rak , Jung Joo Yung , Chang Yong Hoon , Choi Yeon Sun , Schulz Mark J.
Published: March 2009

This paper experimentally investigates the power generation property of carbon
nanotubes in an aqueous environment. Carbon nanotube based films are investigated in this
paper as a new method for power generation based on ionic conductivity of the fluid. It is
demonstrated that a carbon nanotube film that is bonded onto a structure vibrating with an
electrolyte on the surface produces an alternating current without a net fluid flow. The power
produced is smaller than for a piezoelectric material of the same size, but the CNT power
generator is lightweight and has no moving parts, and does not require the structure to be
immersed in an electrolyte. There are various possible applications for nanotube power
generators.
Hysteretic Behaviors of Yield Stress in Smart ER/MR Materials: Experimental Results
Authors: Han Young Min , Nguyen Quoc Hung , Choi Seung Bok , Kim Kyung Su
Published: March 2009

This paper experimentally investigates the hysteretic behaviors of yield stress in
electrorheological (ER) and magnetorheological (MR) materials which are known as smart
materials. As a first step, the PMA-based ER material is prepared by dispersing the chemically
synthesized polymethylaniline (PMA) particles into non-conducting oil. For the MR material,
commercially available one (Lord MRF-132LD) is chosen for the test. Using the rheometer, the
torque resulting from the shear stress of the ER/MR materials is measured, and then the yield stress
is calculated from the measured torque. In order to describe the hysteretic behavior of the fielddependent
yield stress, a nonlinear hysteresis model of the ER/MR materials is formulated between
input (field) and output (yield stress). Subsequently, the Preisach model is identified using
experimental first order descending (FOD) curves of yield stress in discrete manner. The
effectiveness of the identified hysteresis model is verified in time domain by comparing the
predicted field-dependent yield stress with the measured one.
An Analysis of Temperature Stress and Deforming Considering Shrinkage and Creep in Super-Long Frame Structure
Authors: Li Yan Ying , Zhang Yong Sheng
Published: March 2009

To test the temperature stress and deformation of the major platform in Nanjing
Olympic Sports Center, 8 shrinkage members and 3 creep members were poured on the worksite
for comparison analysis. With finite elements analysis, gliding rubber supporters were used on all
the pillar tops. The floor stress would be in a constant compressive stress with pre-stress and
post-cast-span. This method makes the appearance and developments of structure cracks under
effective control. Under temperature changes, the buildings were ensured not to have damageable
cracks. This project was passed with super quality.
Application of Electric Addressing Spatial Light Modulator to the Moiré Measurement
Authors: Wang Qiang , Wang Biao , Ma De Cai , Yu Chang Bin
Published: March 2009

Based on the principle of moiré techniques, a new method combined with Electric
Addressing SLM technique was proposed. The specimen grating is modulated by the SLM system,
and its the frequency can be changed with aid of a 4f Fourier system. The moiré is generated by the
overlapped specimen grating and a reference grating in the Fourier system. Typical test is conducted
with a polyurethane beam. The successful results verify the feasibility of the method, and show its
good potential of further application to the in-plane deformation measurement.
Oscillation Loop for a Resonant Type MEMS Accelerometer and Its Performance under Noisy Condition
Authors: Hyun Chul , Lee Jang Gyu , Kang Tae Sam
Published: March 2009

This paper presents an oscillation loop for an INS (Inertial Navigation System) grade,
surface micro-machined resonant type accelerometer. This resonant type sensor utilizes the
electrostatic stiffness changing effect of an electrostatic actuator. This device produces a frequency
output upon an applied acceleration. A closed loop system called self-sustained oscillation loop is
prerequisite for its operation as a resonant accelerometer. A self-sustained oscillation loop induces
the system’s dynamic states into its primary mode, thus keeps track of its resonant state under
applied acceleration or perturbation. For this, a simple self-sustained oscillation loop is designed
and the feature of the loop is analyzed in the viewpoint of nonlinear dynamic system. From the
standpoint of feedback control system, both determination of resonance point and its stability
analysis are required. In the actual system, which has several noise sources, noise can affect the
output resonant frequency. We analyzed the effect of a noise on oscillation frequency. Finally,
simulation and experimental result is given
Research of Self-Monitoring Mechanism of Electrically Conductive Asphalt-Based Composite
Authors: Wu Shao Peng , Liu Xiao Ming , Mo Lian Tong , Ye Qun Shan
Published: March 2009

Fatigue damage self-monitoring mechanism of graphite modified asphalt-based
composite materials is demonstrated in this paper, as damage (occurring in the 70% of fatigue life)
caused the volume electrical resistance to increase irreversibly. Results showed that when the initial
resistance is relatively high (10k), the resistance variation sensitivity of microcrack is lower, but it
has relatively high sensitivity to microcrack when the initial resistance 1k. The longer the
loading time, the greater the damage, and the greater the resistance increases monotonically
occurred. The resistance increase is attributed to the proximity effect, microcrack and the
disconnection of conductive paths due to shear strength of aggregates. The self-monitoring
mechanism of damage is the resistance change aroused by the variation of interior structure.
A Study on Reduction of Processing Time and Improvement of Strength by Using Photopolymer Resin in the 3DP Process
Authors: Lee Won Hee , Kim Dong Soo , Kim Jung Su , Lee Min Cheol
Published: March 2009

3DP(three dimensional printing) technology is one of SFF(solid freeform fabrication)
technologies which have recently come into a spotlight due to its adaptability to various
applications. This technology has a great advantage in terms of short fabrication time for a
prototype at a low cost, especially when it comes with multi-nozzle inkjet printing technology.
However, it has also a disadvantage since it requires additional curing time, after jetting a binder
material, and post-processing time in order to increase the mechanical strength of a product. In this
study, a novel 3DP process is proposed to overcome slow solidification and elaborate post-process
by adopting photo curing method into the conventional 3DP process. Mechanical properties, such as
tensile and bending strengths, of specimens fabricated with the proposed 3DP process were
measured and compared with those fabricated with the conventional 3DP process. As a result, it is
found that mechanical strengths of specimens from the proposed novel 3DP process show three
times higher than those from the conventional 3DP process. Besides, the overall fabrication time
with the proposed novel 3DP process is about two times faster than that with the conventional 3DP
process, because it does not need additional curing and post-processing time.
The Characteristic Analysis of a Piezoelectric Actuator for Valveless Micropumps
Authors: Lee Sung Hyuk , Heo Seok , Kim Cheol Woong , Yoon Kwang Joon
Published: March 2009

The behavior of a circular piezoelectric actuator for volumetric micropump has been
investigated by using theoretical and finite element analyses. A modified theoretical model was
developed to predict the behavior of a piezoelectric actuator induced by the applied voltage. The
theoretical results for the diaphragm deflection were in good agreement with the results from
numerical simulation. Based on the theoretical analysis, the effects of several important parameters
on actuation performance have been investigated. These parameters include the dimensions and
mechanical properties of the piezoelectric disk, bonding layer and elastic diaphragm materials.
Consequently, it is thought that above theoretical model might be employed as a tool for design and
optimization of the piezoelectric actuator for micropump application.
Transparent and Conductive PEDOT Films on PET Substrate Using an Epoxy Acrylate Binder
Authors: Kim S.Y. , Cho Mi Suk , Nam Jae Do , Choi Hyouk Ryeol , Koo Ja Choon , Lee Young Kwan
Published: March 2009

Flexible and thin conductive films of poly(3,4-ethylenedioxythiophene) (PEDOT) on PET
substrate were obtained by an in- situ vapor-phase polymerization (VPP) method using ferric toluene sulfonate
as an oxidant. The addition of epoxy acrylate resin used as a binder to provide adhesive strength between
PEDOT and PET also afforded the possibility of the surface patterning through UV exposure. The electrical
and optical properties of the conductive PEDOT films were characterized by UV-Vis spectroscopy and
conductivity measurement. Surface resistance below 150./sq. was achieved for 100 nm thick films with
UV-vis-spectrum transparency exceeding 80%. The combination of these properties makes the films highly
suitable for numerous device applications.
Modal Reduced Order Model for Vision Sensing of IPMC Actuator
Authors: Oh Il Kweon , Yeom Seong Won , Lee Dong Weon
Published: March 2009

In order to control the IPMC (Ionic Polymer Metal Composite) actuators, it is necessary
to use a vision sensing system and a reduced order model from the vision sensing data. In this study,
the MROVS (Modal Reduced Order Vision Sensing) model using the least square method has been
developed for implementation of the biomimetic motion generation. The simulated transverse
displacement is approximated with a sum of the lower mode shapes of the cantilever beam. The NIPXI
1409 image acquisition board and CCD camera (XC-HR50) are used in the experimental setup.
Present results show that the MROVS model can efficiently process the vision sensing of the
biomimetic IPMC actuator with cost-effective computational time.
On Computer Aided Impact Experiments - A Case of Drop Weight Experiment -
Authors: Sato Yasuhisa , Nishimura Keiou
Published: March 2009

Stress-strain curves of some kinds of materials at high strain-rate conditions were able to
be determined by a drop weight experiment system which has only to measure the force-time
relation using a load-cell but not to measure directly the deformation or deformation-rate of
specimen. To evaluate the strain-rate or the strain of the specimen it had been necessary to
measure the motion, i.e. the velocity or the displacement of tup and anvil so far. In this new
method the velocity and the displacement of the tup and the anvil which contacted the both end
surfaces of specimen were calculated using a personal computer on the basis of the equations of
motion for the tup and the anvil, respectively. The differential equations, in which the measured
dynamic-force versus time characteristics were contained, were integrated by Runge-Kutta method
using the personal computer. In the differential equation of motion of the anvil, a spring
coefficient K for the rubber cushion beneath the anvil is used. For the first approximation of the
coefficient K is assumed to be the value determined by the oscillation method of cantilever beam.
The spring coefficient K with high accuracy is determined when the computed strain of the
specimen on the basis of the method described above is almost equal to the measured strain of it by
using a micrometer caliper after the dynamic compression. The coefficient K with the higher
accuracy can be obtained the incremental compression experiment using some kinds of hard stop
ring in the prescribed height.
Dynamic Deformation Behavior of Soft Materials at the Low Temperature Using SHPB Technique and Pulse Shaper
Authors: Lee Ouk Sub , Kim Sung Hyun , Han Yong Hwan
Published: March 2009

This paper presents a modified Split Hopkinson Pressure Bar(SHPB) technique to obtain
compressive stress-strain data for a rubber material. An experimental technique with a modified the
conventional SHPB has been developed for measuring the compressive stress strain responses of
materials with low mechanical impedance and low compressive strengths such as a rubber. This
paper uses an aluminum pressure bar to achieve a closer impedance match between the pressure bar
and the specimen materials. In addition, a pulse shaper is utilized to lengthen the rising time of the
incident pulse to ensure stress equilibrium and homogeneous deformation of a rubber. It is found
that the modified technique can determine the dynamic deformation behavior of rubbers under
various conditions such as high strain rate and low temperature effects.
Spectral FEM-Based Dynamic Characterization of Structural Joints: Theory and Experiment
Authors: Lee Usik , Cho Joo Yong , Cho Chong Du
Published: March 2009

A spectral element (SE)-model based frequency-domain method was proposed in the
previous work [1] to identify the dynamic characteristics of a structural joint within onedimensional
structures. In the present work, experimental work is conducted to verify the proposed
method. The bolt-joint is represented by an equivalent joint model with four parameters, and the
four parameters are determined by experimentally measured FRF data. The experimentally
identified bolt-joint is shown to provide the dynamic responses which are in good agreement with
measured dynamic responses.
A Study on the Relationship between Clamping Angle of a Locker and Initial Clamping Force in the Wedge Type Rail Clamp for a Container Crane
Authors: Han Geun Jo , Lee Seong Wook , Han Dong Seop
Published: March 2009

The rail clamp is the device to prevent that a container crane slips along rails due to the
wind blast as well as to locate the crane in the set position through loading and unloading containers
on a vessel in the quay. In order to design the rail clamp, we need to determine the proper wedge
angle to minimize the sliding distance of a roller and the proper clamping angle of a locker to
generate the initial clamping force of a jaw pad. The researches for the proper wedge angle have
conducted. So in this study we look into the relationship between the clamping angle of a locker and
the initial clamping force in the rail clamp with wedge angle of 10. The initial clamping force of
the jaw pad was determined by the clamping angle of the locker. Therefore after we measured the
locking force of a locker and the tensile stress of extension bar with respect to the clamping angle of
a locker, such as 2.18, 3.05, 3.92, 4.80, we compared the results with the FEA results.
Strain-Rate Sensitivity of Concrete: Influence of Moisture Content
Authors: Lin Gao , Yan Dong Ming
Published: March 2009

Understanding the behavior of concrete under dynamic loading conditions is an issue of
great significance in earthquake engineering. Moisture content has an important influence on the
strain-rate effect of concrete. In this study, both tensile and compressive experiments were carried
out to investigate the rate-dependent behavior of concrete. Tensile experiments of dumbbell-shaped
specimens were conducted on a MTS810 testing machine and compressive tests of cubic specimens
were performed on a servo-hydraulic testing machine designed and manufactured at Dalian
University of Technology, China. The strain rate varied in a wide range. The analytical
formulations between the dynamic strength and strain rate were proposed for both compressive tests
and tensile tests. It was concluded from the results that with the increasing strain rate, strengths of
specimens with both moisture contents tended to increase and the increase seemed to be more
remarkable for the saturated specimens; based on the experimental observation, a better explanation
for the dynamic behavior is presented.
Detection of Impact Damage in Composite Plates Using Surface Contact Method
Authors: Chun Heoung Jae , Kim Dang Won , Byun Joon Hyung
Published: March 2009

It is a well known fact that the fundamental causes of most failures in composite
structures are in the forms of incipient damages such as delaminations and cracks which usually
remain undetected until they grow to levels large enough to cause failure. In this study,
unidirectional carbon/epoxy composite plates with known defects are investigated. The known
defects are generated by impacting the composite specimens simulating external collision. A pair of
transmitter and receiver was used for generation of Lamb waves and reception of signals. The
received signals were monitored by scanning the receiver toward internal defect or by scanning both
transmitter and receiver with confined distance over the surface of the composite plates which have
known defects lie beneath them. The proper selection of incident angle and frequency are also
considered. The characteristics of received signals such as amplitude, energy and wave form are
analyzed. The acquired information is used to locate and to measure the size of the impact damage.
The suggested method is very effective if the internal damage is presented closed to surface of the
plate where the conventional pulse-echo method has problems. The proposed technique can be used
widely for the real time and online monitoring of composite structures.
An Experimental Study of Dropped Ply Region in Composite
Authors: Zhao Chun Wang , Xing Yong Ming
Published: March 2009

A micro mechanical study of Carbon/Epoxy composites with internally dropped plies has
been made using micro-moiré interferometry. The experimental results show that there is a stress
concentration region before the dropped ply. Micro cracks were initiated and propagated in this
region. Two failure mechanisms in the dropped ply region were observed.
Bending Collapse Behaviors and Energy Absorption Characteristics of Aluminum-GFRP Hybrid Tube Beams
Authors: Lee Sung Hyuk , Kim Cheol Woong , Choi Nak Sam
Published: March 2009

Bending collapse behaviors and energy absorption characteristics of aluminum-GFRP
hybrid tube beams were evaluated by using experimental tests combined with theoretical analysis.
Hybrid tube beams composed of glass fiber-epoxy layer wrapped around on aluminum tube were
made in autoclave with the recommend curing cycle. The hybrid tube beams showed a considerable
improvement in their bending performance. The maximum bending moment and specific energy
absorption of the hybrid tubes were higher than those of the aluminum tubes. They were also
evaluated as a function of ply orientation and thickness of GFRP layer. A modified theoretical
model was developed to predict the resistance to the collapse of hybrid tube beams subjected to a
bending load. Theoretical ultimate bending moments and moment-rotation angle curves of hybrid
tube beams were in good agreement with experimental ones. Hybrid tube beams strengthened by
GFPR layer with 90°/0° and 45°/-45° ply orientation showed an excellent bending strength and
energy absorption capability, respectively. Therefore, on the basis of above results, it was
concluded that aluminum-GFRP hybrid tube beams might be employed as reinforcing and/or energy
absorbable light weight space frame.
Measurement of Stress-Optical Coefficients of COC’s with Different Composition
Authors: Kim Jong Sun , Yoon Kyung Hwan , Kornfield Julia A.
Published: March 2009

Rheo-optical and mechanical properties of Cyclic Olefin Copolymers(COC’s) with
different composition have been investigated across the glass transition temperature. Accurate
measurement of stress or strain-optical coefficients and elastic modulus data across the glass
transition are essential for predicting optical anisotropy in many optical products like pickup
lenses and waveguides in LCD backlight unit since the material of these products have both
flow and thermal history from the melt to glass. To obtain stress-optic behavior in the wide
frequency region including rubbery, glassy and glass transition regime, extensional bar-type
device was used. A shear-sandwich tool was used in the melt region. Master curves for
modulus, stress-optical and strain-optical coefficients have been obtained in wide frequency
region. The stress-optical coefficients of COC’s with mol fraction of norbornene, 60 ~ 70%,
showed almost constant between -8 and -9 Br at glassy region and between +920 and +1,160
Br in the melt region. Even though the glass transition temperature showed the difference of
35, the stress-optical coefficients of COC’s with different composition showed almost
same extreme values