bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Laser Texturing Parameters on Wear Properties of Rollers with Fractal Geometry
Authors: Liu Hong Bin , Wan Da Ping , Hu De Jin
Published: March 2009

The processing parameters of laser texturing are linked with the wear property of roller surface based on the relationship between the fractal parameters and surface roughness. The influence of laser power density, scanning speed and pulse width on the roughness is analyzed though experiments. The effect of fractal parameters on the wear rate of the roller is analyzed with fractal geometry model for wear prediction. Condition of achieving engineering surface with optimal fractal dimension is presented and the expression of the optimal fractal dimension is derived. It shows that the roughness of laser textured surface and normalized wear rate are mainly determined by laser power density and fractal dimension, respectively. Moreover, to get the textured surface with smallest nominal wear rate, processing parameters of laser texturing, especially the laser power density, should be controlled properly besides the material properties of the roller. The result will provide guidance for the processing.
Technique Project and Theoretic Research on Surface Finishing to the Wheel Hub
Authors: Li Wen Hui , Yang Sheng Qiang , Yang Shi Chun
Published: March 2009

It is a difficult problem of surface finishing to the wheel hub. From the structure and
finishing request of wheel hub and barrel finishing mechanism, a new technique project for wheel
hub finishing is put forward and established. Its finishing mechanism is explained, and theoretic
research is done. By analyzing effect factors and their rules, theoretic basis is settled for
experimental research and industrial application. The study indicates that this process is very
effective for wheel hub finishing.
Study on Mechanism of Vibration Cutting
Authors: Tong Fu Qiang , Zhang Yong , Zhang Fei Hu , Lu Jing Yu , Gu Li Zhi , Chen Ya Chun
Published: March 2009

Research on the mechanism of vibration cutting was carried out by analyzing the process of vibration cutting and comparing the model of vibration cutting and conventional cutting. Proper speed coefficient k can help to reduce the average cutting force while increase the cutting efficiency according to the velocity and acceleration equation of vibration tool. Dynamic model of conventional cutting and vibration cutting were built respectively. Compared with conventional cutting, it’s easier for vibration cutting to realize productivity gain, high machining accuracy and good surface finish.
Study on Influencing of Technological Parameter with Tools Wear during Turning Fluorophlogopite Glass-Ceramics
Authors: Ma Lian Jie
Published: March 2009

The characteristic of tools wear is analyzed through turning fluorophlogopite
glass-ceramics. And the process of tools wear can be divided into three periods. Through single
factor test, the influence of tools wear was discussed such as tool material, cooling conditions,
cutting depth and feed speed. The study indicates, the tools material and cooling condition are
major factors to affect tools wear. The high-speed steel tool is not suitable for turning
fluorophlogopite. Because sustaining time of cutting is short and efficiency is low in machining, the
tungsten-cobalt carbide tool is not perfect tool. And ceramics tool is better than the both. The tools
wear rate can be decreased under cooling conditions. Influential curve of tools wear rate versus
cutting depth is a part of parabola curve.
Tool Wear in High-Speed Milling of Ti-6Al-4V Alloy
Authors: Zhang Song , Li Jian Feng , Liu Feng Shi , Jiang Feng
Published: March 2009

Titanium alloys are widely used in the aerospace industry for applications requiring high strength at elevated temperature and high mechanical resistance. However, titanium alloys are classified as extremely difficult-to-cut materials owing to their physical, chemical, and mechanical properties, which result in the low material removal rate and the short tool life. This paper presents an experimental research of the tool wear patterns and relevant wear mechanisms during high-speed milling of Ti-6Al-4V with cemented carbide inserts. SEM-EDX analysis showed that nose wear and edge wear were the main tool failure modes during high-speed milling process, which were different from the wear patterns under traditional cutting conditions. Adhesion, attrition and diffusion wear mechanisms, as well as the cracks were responsible for the tool wear.
Model and Simulation of Slurry Velocity and Hydrodynamic Pressure in Abrasive Jet Finishing with Grinding Wheel as Restraint
Authors: Li Chang He , Hou Ya Li , Xiu Shi Chao , Cai Guang Qi
Published: March 2009

The models for three-dimensional velocity and hydrodynamic pressure of abrasive fluid
in contact zone between wheel and workpiece on abrasive jet finishing with wheel as restraint were
presented based on Navier-Stokes equation and continuous formulae. The emulational results
shown that the hydrodynamic pressure was proportion to grinding wheel velocity, and inverse
proportion to the minimum gap between wheel and workpiece and the maximum pressure was
generated just in the minimum clearance region in which higher fluid pressure gradient occur. It can
also be concluded the pressure distribution was uniform in the direction of width of wheel except at
the edge of wheel because of the side-leakage. The velocity in the x direction was dominant and the
side-leakage in the y direction existed. The velocity in the z direction was smaller than the others
because of the assumption of laminar flow. The smaller the gap distance is, the larger the velocity in
the x direction. The magnitude of the velocity is also proportional to the surface velocity of the
wheel.
Research on Dynamic Physical Simulation of HSC Comprehensive Characteristics
Authors: Xu Dao Chun , Feng Ping Fa , Zhi Jing Feng , Yu Ding Wen , Wu Zhi Jun
Published: March 2009

The physical simulation of high-speed cutting (HSC) is a hot research in cutting field.
Dynamic physical simulation is the key technical difficulty of physical simulation. It can afford the
machining process parameters quickly and efficiently, such as cutting stress, cutting temperature, tool
wear etc., which have important academic and practical value. The cutting theoretical mathematical
model based on the elastic-plastic mechanics and tribology was built up. The two-dimensional /
three-dimensional (2D/3D) HSC dynamic physics simulation models were built up by the finite
element method. The stress, thermal distribution and tool load etc. during the high speed machining
(HSM) was obtained. These parameters provided key technical basis for the establishment and
optimization of HSM parameters. They can save much machining experiments cost and improve the
processing efficiency.
Study on Impact Disrepair Mathematic Model and Groove Optimization of Cutting Tools for Machining Carbon Structural Steel
Authors: Cheng Yao Nan , Li Zhen Jia , Zhao Yong Gang , Sun Wei Jun
Published: March 2009

Based on the theoretic analysis and experiments on milling the carbon structural 45 steel
with the flat rake milling insert and the waved-edge milling insert with complex 3D grooves which
is developed by HarBin University of Science and Technology, we have studied on the impact
disrepair mathematic model and groove optimization. On the basis of the milling force mathematic
model and force density function of the waved-edge milling insert with complex 3D grooves the
author built, we have the finite element analysis and blurry synthetical judgement of the 3D stress
field, and forecast that the anti-impact disrepair capability of the waved-edge milling insert is
choiceness. We find out the difference of the impact disrepair invalidation types between different
grooves milling inserts by the experiments. Based on the plentiful and systemic impact disrepair
experiments, as the emphasis in this paper, we build the impact disrepair life cumulating
distribution function mathematic model by the mathematics statistic method and have contrast
analysis of the impact disrepair average lives between the two types of milling inserts, and prove
that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. All these
studies provide the theoretic and experimental basis for solving the cutter disrepair which is the key
problem in the automatization production and groove optimization.
A Study of Exit-Burr Formation Mechanism Using the Finite Element Method in Micro-Cutting of Aluminum Alloy
Authors: Lu Dong , Li Jian Feng , Rong Yi Ming , Sun Jie , Zhou Jun , Wang Zhong Qiu
Published: March 2009

A burr formation process in micro-cutting of Al7075-T7451 was analyzed. Three stages
of burr formation including steady-state cutting stage, pivoting stage, and burr formation stage are
investigated. And the effects of uncut chip thickness, cutting speed and tool edge radius on the burr
formation are studied. The simulation results show that the generation of negative shear zone is one
of the prime reasons for burr formation. Uncut chip thickness has a significant effect on burr height;
however, the cutting speed effect is minor. Unlike in conventional cutting, in micro-cutting the
effect of tool edge radius on the burr geometry can no longer be neglected.
Study on the Correlativity between Grinding Parameters and Surface Residual Stresses in Ceramic
Authors: Zhang Guang Xiu , Lin Bin , Shi Zhen Peng
Published: March 2009

The generation and distribution of workpiece surface and sub-surface residual stress were
predicted through the dynamic finite element simulation of the grinding ceramic process. The base of
the simulation is that the thermo elastic-plastic finite element theory and the coupling of grinding
forces and temperature were adopted. The results obtained from X-ray diffraction measurement
compared well with the values calculated from theory. The correlation between grinding parameters
and the ceramic residual stresses was investigated. The research results show that the normal grinding
force is the primary factor responsible for the generation of residual stress in grinding ceramic. The
mechanical effect of the grains is to affect the magnitude, the depth of penetration and the gradient of
the residual stresses.
Control and Analysis of Nonlinear Error for 5-Axis Machining of Hybrid Machine Tool
Authors: Shi Hong , Xu Wei , Cai Guang Qi
Published: March 2009

Complex parts are the main object for CNC machining. The 3-TPS hybrid machine tool can
achieve 3-axis, 4-axis, 5-axis, vertical and horizontal machining. The analysis of nonlinear error of
the 3-TPS hybrid machine tool on 5-axis machining and the reduction the error by self-adaptation
linearization are introduced in the paper. The obtained formula for nonlinear error can be used in
different situations and estimate three-dimensional cutter evelope forming error.
Fractal Characterization and Simulation of Surface Microtopography Machined with Abrasive Jet Precision Finishing with Grinding Wheel as Restraint
Authors: Liu Feng , Gong Ya Dong , Ke Chang , Cai Guang Qi
Published: March 2009

Abrasive jet finishing process is a novel process whose objective is to remove surface defect layer and to diminish roughness and ripple after grinding. Experiments were performed with plane grinderM7120 and workpiece material 45# steel which was ground with the surface roughness values of Ra =0.2-0.6 μm . The machined surface morphology was studied using SEM and the microcosmic geometry parameters were measured with MICROMESVRE2 instrument. In this paper, with the fractal dimension, Ra , Rq and the supporting rate curve, the surfaces of grinding machining and abrasive jet finishing machining were researched. The result indicated that the machined surfaces changed from continuous parallel micro-groove and plough to randomly distributed discontinuous micro-pit could be observed with the increase of machining circles and surface roughness was obviously improved. Furthermore, the isotropy surface and uniformity veins both parallel and perpendicular machining direction were attained by abrasive jet precision finishing with grinding wheel as restraint. The supporting rate curve of the surface profile can be increased. This is favorable for the wearable capability of the workpiece.
Theoretical Study on the Bending Deformation of Metal Plate Induced by Repetitive Laser Shot Peening
Authors: Zhou Jian Zhong , Huang Shu , Ji Xia , Du Jian Jun , Yang Chao Jun , Zhang Yong Kang
Published: March 2009

The laser peen forming (LPF) uses high-power pulsed laser beam replacing the tiny medium balls to peen the surface of plate and generate compressive stress near the surface, the metals respond to this residual stresses by elongating at the peened surface and effectively bend the overall shape. In this paper, the deforming process of metal plate induced by repetitive pulsed laser was discussed from theory firstly, and the bending mechanism of LPF was investigated. Then a mathematical model of bending curvature concerning the depth of residual stress was presented, the influence of residual stresses on the deformation of plate was analyzed. Lastly, the line-track-peening experiment for SUS 304 plate was carried out to evaluate the reasonability of the theoretical analysis model.
Experiment Study on Abrasive Waterjet Machining Mechanisms of Brittle Materials
Authors: Zhu Hong Tao , Huang Chuan Zhen , Wang Jun , Li Quan Lai , Che Cui Lian
Published: March 2009

The erosion process of abrasive waterjet (AWJ) on target material is very complicated and a complete clear understanding about material removal mechanisms in AWJ machining has not been obtained. In this paper, an experiment study on AWJ machining mechanisms of brittle materials is introduced so as to understand the actions of water jet and abrasive particle in material removal process and some experiment evidences of the change of material removal mechanisms have been obtained.
Cutter Selection in the Milling of Thin-Web Components Considering the Machining Errors Control
Authors: Wu Kai , He Ning
Published: March 2009

The existent studies on the milling of the thin-web components are reviewed first, then
the cutter selection strategies are discussed theoretically based on the mechanistic model of the
milling cutter, and several experiments are carried out to verify the theoretical analysis. At last, the
conclusions are given on the cutter selection strategy in the milling of the thin-web components.
Study on the Shaping Law of Precision Numerical Controlled Electrochemical Contour Evolution Machining
Authors: Kang Min , Xu Jia Wen
Published: March 2009

Numerical Controlled Electrochemical Contour Evolution Machining (NC-ECCEM) is
one of the most important development in Electrochemical Machining (ECM). In order to improve
the machining accuracy of NC-ECCEM technology, the research works on precision NC-ECCEM
technology are needed, and especially the study on its shaping law is significant for improving the
machining accuracy of workpiece profile. In this paper, the shaping law of machining the planar
surface by use of a kind of inner-spraying cathode with rectangle section was studied. First, the basic
differential equations of shaping law in the case of cathode movement were established. Then,
considering the structure of the cathode, the methods for calculating the side gap in machining the
planar surface was given. Finally, the experiments of machining the planar surface were carried out.
Experiments show that the calculated side gaps are bigger than the actual values, but the change trend
of calculated side gaps with machining process parameters is coincident with the actual side gap
change trend.
Calcium Phosphates / Biphosphonates Combinations…Towards a Therapeutic Synergy
Authors: Bujoli Bruno , Bouler Jean Michel , Guicheux Jerome , Gauthier Olivier , Janvier Pascal
Published: March 2009

The integration of drugs and devices is a growing force in the medical industry. The incorporation
of pharmaceutical products not only promises to expand the therapeutic scope of device technology
but to access combination products whose therapeutic value stem equally from both the structural
attributes of the device and the intrinsic therapy of the drug. For example, the orthopedic industry is
exploring drug-coated hip, knee and bone reconstruction implants capable of promoting healing as
an added therapeutic benefit for device recipients. In this context, the drug is eluted locally, being
targeted in a specific site of interest, thus offering a convenient strategy to avoid adverse effects
commonly observed for systemic treatments of some diseases, as an additional benefit. In addition,
these new technologies are generally well adapted to the development of minimally invasive surgery
for their implantation.
In this context, given the wide use of calcium phosphates (CaPs) and bisphosphonates (BPs) for the
therapy of bone-related affections, there was great interest to investigate the chemistry taking place
when combining the two systems since: (i) it could provide better insight in the mechanism of BP
fixation on bones (ii) such combination could act as efficient BP delivery systems when implanted
in bone defects.
Advances in Cyclic Behavior and Lifetime Modeling of Tempered Martensitic Steels Based on Microstructural Considerations
Authors: Velay Vincent , Delagnes Denis , Bernhart Gérard
Published: March 2009

Cyclic behavior and life prediction of two tempered martensitic steels (AISI H11 and L6)
are investigated under thermo-mechanical loading conditions. Two non isothermal constitutive
models developed in the same framework of the thermodynamics of irreversible processes are
introduced. The first one, in relation with the tempering state, considers the fatigue-ageing
phenomena whereas the second one is intended to take into account more complex loading paths.
This last non unified approach allows to define different strain mechanisms which can be related to
microstructural considerations. The strain-stress parameters provided by both approaches can be
introduced into a lifetime model which is based on continuum damage mechanics.
By Leaps and Bounds: The Realization of Jet Propulsion through Innovative Materials and Design
Authors: Danko Gene A.
Published: March 2009

Innovations in gas turbine engine design and materials are tracked from the earliest days
of functional engines to the present. Materials and design are shown to be mutually interdependent,
driving engine capability to unprecedented levels of performance with each succeeding product
generation.
Calibration Technology of the Articulated Arm Flexible CMM
Authors: Wang X.Y. , Liu Shu Gui , Zhang Guo Xiong , Wang B. , Guo L.F.
Published: March 2009

A simple and practical calibration method is proposed to calibrate the articulated arm
flexible CMM. Firstly, a quasi-spherical coordinate system is put forward based on DH method
according to the special structure of the articulated arm flexible CMM. This calibration method is
presented to determine and separate machine parameters and errors in a creative way based on
multiple reversal technology. Experiments were carried out for a Faro Platinum 4ft articulated arm
CMM by using a Chameleon 9159 5Q orthogonal CMM. The results prove the feasibility of the
proposed method for articulated arm CMM calibration, and all parameters are separated completely.
It provides a theoretical base for introducing error compensation and improves the measurement
accuracy of the articulated arm CMM.
Use of Air Beam for In-Process Optical Measurement in Precision Machining
Authors: Gao Y. , Xiao K. , Zhang Y. , Chan Y.S.
Published: March 2009

In order to allow optical signals to reach the workpiece surface to realize in-process optical measurement through an opaque coolant, a locally transparent region generated by use of an air beam is examined to allow better understanding of the fluid assisted in-process optical measurement approach. With the air beam used, the problems associated with the diluting effect on coolant concentration and the measurement error due to the optical transmittance through multiple media can be avoided. The working principle and the experimental results for testing the proposed method are presented and discussed.
A Study on Surface Material Measures for Areal Surface Texture Measuring Instruments: Measuring Conditions for the Areal Profiling
Authors: Nemoto Kentaro , Yanagi Kazuhisa , Aketagawa Masato , Kanda D. , Yoshida I. , Uchidate M.
Published: March 2009

This paper describes the software gauge data for surface texture standard using the
non-causal 2D auto-regressive model (A-R model). This model can provide with 3D irregular surface
topography and intentional geometrical characteristics from specified surface texture parameters. The
measurement area consists of a periodical combination of the generated sampling area data. The
surface roughness parameters introduced from the gauge data on a defined evaluation area can be
insensitive to size and location of the evaluation area size. Adequate measuring conditions to utilize
the surface material measures were investigated and then the evaluation area and sampling distance
for areal profiling by a stylus instrument were clarified.
Lie Detection Experiment Methodology: Infrared Image and Spectrum Analysis
Authors: Li Wen Shi , Li H. , Lu S. , Hu Q.
Published: March 2009

Infrared-based lie detection experiment methodology can open the human life window
(0.6µm-16µm) through which the body spontaneous or active infrared responding images be gathered
and analyzed by spectrum scoring in features of geography and computation. These raw images
mainly load the indirect physiological, biochemical or direct brain evidences of cognitive lie and
truth. Aiming at the mimic play card test, three tests of lie detection based on the medium or near
infrared spectrum (NIRS) in four kinds of spectrum analysis are discussed. The instruments include
the lock-in phase amplifier of Stanford University, TTM (Thermal Texture Maps) in US patent, and
self-made auricular point NIRS (Chinese Jiangsu appraisal certificate No. 1017). The subjects’
signals sampling positions are on glabella, brows, abdomen or auricular point Antitragus No. 2. The
spectrum analysis methods utilize the self-built feature extraction algorithms, the wavelet microscopy,
and the bispetrum in validities of 92%, 100%, 80% and 80%. The results support the lie-truth law of
“truth be the baseline of lie detection in view of brain power” (the statistical finding from review of
3D-MRI lie-detection reports included our work, subjects n = 4) for making foundation to the future
lie detection 3D-SoC design.
Temperature Characterization for Nano-Polishing of PCD Composites
Authors: Chen Y. , Zhang Liang Chi , Arsecularatne Joseph A.
Published: March 2009

This paper discusses the temperature characterization for nano-polishing of polycrystalline
diamond composites (PCDCs) by combined experimental and theoretical modelling. It was found that
a higher polishing pressure-speed combination results in a higher temperature rise and material
removal rate. To optimize the nano-polishing of PCDCs and achieve a surface roughness of Ra = 50
nm, the interface temperature at polishing needs to be maintained at an appropriate level.
Micro-Nanometer Positioning Control of Bimodal Ultrasonic Motor Based on Wavelet Differential Actuation Pattern
Authors: Xu Cong Yu , Yu Xiao Fen
Published: March 2009

This paper has developed the bimodal USM a novel actuation pattern, which can actuate
the bimodal USM in nanometer magnitude with single actuation pattern instead of combination
control of AC actuation pattern, pulse actuation pattern and DC actuation pattern. The novel actuation
pattern utilizes a single chip micro-computer to produce a kind of wavelet actuation unit which
contains several sine voltage waves with different amplitudes, each wavelet actuation unit is exerted
on bimodal USM according to the instruction, by which the step control is obtained. Across the two
electrodes of bimodal USM, the differential wavelet actuation voltages are applied to reduce the
moving distance of each actuation step, thus the nanometer magnitude actuation sensitivity is
achieved. The grating is used as position sensor and the subdivision formulae of mutual compensation
functions are adopted to promote the real-time response. The experiment indicated that, with the
novel wavelet differential actuation pattern, the actuation characteristic of bimodal USM was
improved, the micro-nanometer positioning control was easy to be implemented and the important
positioning control parameters under every different actuation conditions could be obtained through
the study in the process of actuation.
Investigation on the Noise Separation in Watt Balance Experiments
Authors: Zeng W. , Jiang Xiang Qian , Scott P. , Blunt L.
Published: March 2009

The detection of stationary and non-stationary noise in environmental vibration data is an
important issue when considering the precision of the Watt balance, an electromechanical apparatus
for the new definition of the kilogram in the international system of Units (SI). In this paper, the
authors propose a frequency histogram method to find the structure of the stationary noise from large
amount of datasets. For the non-stationary noise, the authors propose a wavelet based denoising
methods to distinguish the transient events from the background “noise”, to find their duration and
content and to identify their location in time.
The Development of a Separated Mini-Environment
Authors: Zhang Hui , Cai Z. , Fan K.C.
Published: March 2009

This paper develops a new separated mini-environment to provide a constant temperature
chamber for the placement of Micro/Nano-metrology instrument. In this paper, the rule of
temperature change with time under natural convection and coercive convection is presented. The
measurement and control system is composed of TEC, programmable power source and precise
temperature measurement system. The mathematic model of the constant temperature chamber is
identified making use of system identification theory and system identification toolkit of MATLAB.
The temperature stability is improved by applying auto-adaptive PID method. Experiments show
that the temperature fluctuation of a single-point is less than 0.02°C and the whole field is within
0.05°C. The goal of high-precision temperature control is achieved.
Electroplated Nickel Composites with Micron- to Nano-Sized Particles
Authors: Wielage Bernhard , Lampke Thomas , Zacher Manuela , Dietrich Dagmar
Published: March 2009

Electroplated nickel coatings provide ductility, excellent corrosion resistance and good wear resistance, which qualifies them to meet complex demands of engineering, microtechnology and microelectronics. The co-deposition of particles is a promising alternative to deposit layers with adequate microstructure and properties avoiding the rise of residual stress. The incorporation of the sufficient quantity of particles, monodisperse distribution and downsizing to nanometre scale affect the amount of strengthening by dispersion hardening. To avoid agglomeration in the electroplating bath as well as in the layer is a challenge which has been met by simple Watts nickel electrolyte with a minimum of organic additives and adequate bath agitation comprising sonication, i.e. the exposure of the bath to high-frequency sound waves. Well-dispersed hard particles (titanium oxide and silicon carbide) were incorporated in nickel films. The focus was set on the correlation between the gained microstructure of the composites with particles from micron to nanometre scale and the electrochemical and mechanical properties. Corrosion was quantified from polarisation curves and volumetric erosion measurements. Wear resistance was evaluated by scratch energy density studies, oscillating sliding wear testing and cavitation wear testing and compared to indentation hardness results. Sonication and particle downsizing result in matrix grain refinement and dispersion hardening. Incorporation of different particles with respect to different material and size proved to meet different demands. Submicron TiO2 is best for high corrosion resistance, sonicated nickel without particle incorporation is best for high abrasion resistance, nano TiO2 is best for oscillating sliding wear resistance and submicron SiC is best for cavitation wear resistance.
Excavation Damage in Unsaturated Porous Media
Authors: Arson C. , Gatmiri B.
Published: March 2009

This paper presents a damage model dedicated to unsaturated brittle rocks. It mixes
phenomenological and micro-mechanical concepts, and is formulated based on the use of
independent state variables (net stress and suction). The expression of the liquid permeability is
modified in order to represent the influence of fracturing on interstitial fluid flows.
Numerical Characterization and Validation of Vehicle Collisions
Authors: Grimaldi Alfonso , Soprano Alessandro , Caputo Francesco
Published: March 2009

In the recent years the road accident analysis has been one of the main fields of research
for automotive engineering, because of the heavy costs which Europe has to sustain each year in
terms of injuries, fatalities and related costs. In this paper, starting from an impulsive model
available in literature, a numerical characterization of vehicle collisions and deformation process is
proposed and validated, identifying the main parameters which describe the vehicle impact
behaviour. The study, conducted by using both empirical and numerical data (simulated trough Ls-
Dyna), analyses the impact process by considering several situations, with different severity and
geometry of impact; furthermore, with reference to the main parameters which describe the vehicle
behaviour in the impact, the authors present a wide analysis, classified according to the severity of
impact and to the different parts of the vehicle structure which absorb the impact energy.
Influence of Anisotropic Properties Upon Stress Intensity Factors under Biaxial Stress
Authors: Shimamoto Akira , Ohkawara Hiroshi , Nam Jeong Hwan
Published: March 2009

In this study, stress intensity factors were investigated and determined by photoelastic and caustics methods to clarify the mechanical behavior of crack tips under various biaxiality ratios. Polycarbonate (PC) plates with isotropic and anisotropic properties were used as specimens. The results confirmed that regardless of biaxiality ratio or the material’s property only ‘KI’ was generated in cases of a crack angle θ = 0º. It was also confirmed that only KI was generated in the isotropic PC plate with crack angle θ = 45º under a biaxial load (1:1). When the biaxiality ratio is more than 1:1 with a crack angle θ = 45º, both KI and KII are simultaneously generated in the isotropic specimen. Furthermore, KI, and KII values are influenced most by the extrusion direction in the anisotropic specimens as the biaxiality load ratios increase.
A New Method to Calculate Dynamic Stress Intensity Factor for V-Notch in a Bi-Material Plate
Authors: Li You Tang , Rui Zhi Yuan , Yan Chang Feng
Published: March 2009

The stress singularity eigen-equation for V-notch in a bi-material plate is obtained. A new definition of dynamic stress intensity factor of a crack perpendicular to bi-material interface is put forward, and then is extended to any V-notch in bi-material plate. A formula of stress extrapolation method to calculate dynamic stress intensity factors of V-notch in bi-material plate is obtained. As an example, the three points bending sample with two materials is investigated.
Crack Propagation Behavior of Asphalt Concrete; Part I: A Study into Influence of Different Materials
Authors: Xie Tao , Jiang Ze Zhong , Qiu Yan Jun , Lan Bo
Published: March 2009

The fracture resistance of asphalt materials significantly influences the service life of
asphalt pavements and consequently affects the maintenance and rehabilitation costs of the
pavement network. Therefore, there is significant interest in understanding the mechanism of
fracture in asphalt pavements and in developing analysis tools that would lead to the selection of
asphalt materials with increased fracture resistance. Study of cracking behavior of asphalt mixtures
should be conducted in a micro-scale level to have a real simulation of crack propagation. Using
SIEMENS SOMATOM plus X-ray CT (computerized tomography) and multi-functional testing rig,
a dynamic observation of cracking propagation of hot mix asphalt was conducted in this research.
Failure process under compressive pressure was recorded using CT images and CT numbers. The
direct responses in density change of Marshall Samples under a CT-compressive process are change
of CT numbers. Cracking propagation in the samples can be clearly observed and failure mode and
stress-strain behavior can then be simulated. The tests reported provide important theoretical
fundamentals to study the cracking behavior and failure mechanism of asphalt mixtures.
The Effect of the Singularity Induced by the Free Surface on Fatigue Crack Growth in Thin Structures
Authors: Hutař Pavel , Náhlík Luboš , Knésl Zdeněk
Published: March 2009

In many industrial applications is necessary to predict fatigue lifetime of thin structures, where the stress field near the crack front have a real three-dimensional nature. Due to the existence of vertex singularity in the point where the crack front touching free surface, crack propagation in 3D structures cannot be reduced to a series of plane strain or plane stress problems along the crack front edge. The paper describes the influence of vertex singularity on the distribution of the stresses around the crack front for three-dimensional body. The distribution of the stress singularity through the thickness of the specimen gives us indication of the crack behavior in thin structures. The estimation of the thickness of the specimen where the change of singularity plays an important role on fatigue crack growth rate (in dependence on Poisson’s ratio) is carried out. The results contribute to a better understanding of the crack behavior in thin structures, and can help to more reliable estimates of their residual fatigue life.
The Elastic-Viscoplastic Field at the Mixed-Mode Crack-Tip under Compression and Shear
Authors: Liang Wen Yan , Wang Zhen Qing , Zhou Bo , Lv Hong Qing
Published: March 2009

Under the assumption that the viscosity coefficient is in inverse proportion to the power
law of the equivalent plastic strain rate. The friction touch effect between viscosity and crack-tip
surfaces is considered, the asymptotic solution is established for elastic-viscoplastic field at the
mixed-mode quasi static crack-tip under compression and shear. The numerical solution at crack-tip
without stress and stain gap is obtained. The variation of numerical solution is discussed for the
mixed-mode under compression and shear according to each parameter. Through numerical results
and analysis for the mixed-mode crack-tip field under compressing and shear, it is whole plastic
without elastic unloaded section, viscosity effect is an important factor when propagating crack-tip
field.
Review of Experimental Models for Confirmation of Mathematical Models of Gears
Authors: Aberšek Boris , Flašker Jože
Published: March 2009

In order to calculate the service life as precisely and reliably as possible we need good
mathematical models for describing loading, geometry, properties of materials and fracture
mechanics parameters. It can be established whether a mathematical model is precise and reliable
only by comparison of results of the method such as analytical methods in case of simple problems
and experiment when real complex structure are deal with. Since gears and gearing belong to the
second group, by correctly selected and developed test pieces and carefully planned experiments we
obtained results with which we confirmed and justified the mathematical model for calculating
mentioned parameters. To this end we will show in this paper series of experimental methods and
test pieces used on the gears.
Bending and Shear Strength of I-Slab with Polystyrene Forms
Authors: Kim Seung Hun , Lee K.K. , Lee Han Seung , Lee K.J. , Kang In Seok
Published: March 2009

Where the self weight of the overall slab needs to be considered, the quantity of in-situ
concrete required can be reduced by the introduction of polystyrene void forms supplied and fixed to
the precast panel during manufacture. In this study, new I-slab system with polystyrene form and
precast concrete deck is proposed to reduce the construction period and the self weight of the slab.
This paper presents experimental works on the bending and shear of the I-slabs. Five specimens were
tested. The main parameters of experiments were the hole diameter of polystyrene form and the
thickness of slab. Structural performance of I-slab was evaluated on the basis of failure mode,
load-displacement curve, and ultimate strengths. Based on the test results, the critical punching shear
sections were changed as test variables, so the punching shear strengths were very different. Test
results indicated that the developed I-slab were very effective to increase the strength because of self
weight reduction.
Dynamic Damage Analysis of SRC Frame Structure under Earthquake Action
Authors: Zheng Shan Suo , Wang Bin , Zhang Liang , Li Lei , Wang Wei
Published: March 2009

Structures may enter into nonlinear stage under strong earthquake, so precise prediction of
nonlinear behavior for building structure in earthquake is important which can assess the earthquake
resistance safety of structures accurately. The exact numerical analysis model is required in actual
engineering. In this paper the concept of nonlinear dynamic damage is introduced in steel reinforced
concrete (SRC) composite structure, based on the theory of continuous damage mechanics. The
damage variable is defined and computed by effective plastic strain of material, furthermore, concrete
dynamic constitutive model is derived which considered plastic strain of material. Finally, the damage
dynamic balance equation is established. Via comparison with test results of a three-story, two-bay
SRC frame model which is tested on a shaking table, it is shown that the results of numerical analysis
agree well with test results, indicating that the nonlinear dynamic balance equation is capable of
describing the dynamic response of SRC frame structure with satisfactory accuracy. The research
supplies theoretical basis for the seismic behavior analysis of SRC high-rise buildings.
Corrosion Behavior and Mechanism of a Cu-Ni Alloy in Marine Environment
Authors: Li Qing Fen , Li Chun Hui , Qiao Ying Jie
Published: March 2009

The microbiological influenced corrosion (MIC) behavior of a marine pipeline Cu-Ni
alloy in the sterile seawater and sulfate-reducing bacteria (SRB) solution was investigated. Results
show that severe pitting corrosion appeared on the specimens in the SRB solution. The corrosion
potential of specimen in the SRB solution was much lower than that in the sterile seawater and the
polarization resistance of specimen in the SRB solution decreased quickly after a period immersion
and became much lower than that in the sterile seawater. Besides, the results of EDS and XRD
show that the content of element Ni and Fe of the Cu-Ni alloy decreased greatly and the high
content of element S appeared after 30 days immersion in the SRB solution. It was concluded that
the SRB accelerated the corrosion process of the Cu-Ni alloy greatly. The MIC mechanism of the
alloy in marine environment is discussed.
Thermal Fatigue of Thermal Barrier Coatings by Atmospheric Plasma Spraying
Authors: Qi Hong Yu , Ma Hai Quan , Li Xu , Yang Xiao Guang , Shi Duo Qi
Published: March 2009

Turbine vanes and blades are the most intensively loaded elements in that they are
subjected to a large variety of mechanical and high temperature loads. The thermal barrier coatings
(TBCs) are widely used on different hot components of gas turbines, as blades and vanes, for both,
power engineering as well as aeronautical applications. Currently, two methods are used for
depositing TBCs on substrate, which are plasma spray (PS) and electron beam-physical vapor
deposition (EB-PVD). A typical TBCs system consists of two thin coatings, including a ceramic
coating and a metallic bond coat. Despite considerable efforts, the highly desirable prediction of their
life time is still a demanding task. The PS coating was focused on in this work. Firstly, the TBCs
systems are multiplayer material systems. The material properties are not easily determined, such as
Young’s modulus of the top-coating of TBCs. Using the resonant frequency and the composite beam
theory, the Young’s modulus of APS TBCs was gotten under from room temperature to 1150°C. Then
using a commercial finite-element program, the model geometry is that of a cylinder specimen. The
interface region between bond coat and top coating is modeled and meshed with a sinusoidal
geometry. The temperature was designed and cycled over a range from room temperature to 1050°C.
The force-air-cooling was designed to form temperature gradient across the thickness of TBCs.
Finally, the fatigue life of TBCs was predicated. The maximum relative error is 20.1%.
A Numerical Analysis of Double Notch on Stress Distribution in Single Lap Aluminium Joints
Authors: Zheng Xiao Ling , Li Zhi , You Min , Yu Shan , Zhao Mei Rong
Published: March 2009

The stress distributed in the mid-bondline of the joints made of aluminium alloy and an epoxy adhesive was determined with the ANSYS software. The results from the FEA showed that the values of the peak stresses of the all the stress components (including the longitudinal stress Sx, the peel stress Sy, the shear stress Sxy, the 1st principal stress S1 and the von Mises equivalent stress Seqv) distributed in the mid-bondline are changed a little as the notch distance L was increased while the notch depth d was not great than 0.6mm. But the evidently changes occurred when the notch depth d was great than 0.9 mm for the stress Sx, Sy and S1 distributed in both the mid-bondline and the interface of the lap zone. When taken the stress distributed in the middle part of the lap zone into account, the peak stress at the point in the mid-bondline corresponding to the edge of the notch decreased firstly and then increased again as the notch distance L was increased from 0 mm to 8 mm. The proper geometry of the notch in the specimen was chosen by finite element analysis.
Contributions in the Study of Hybrid Layered Composites under Static and Variable Loads
Authors: Constantin Nicolae , Anghel Viorel , Găvan Mircea , Sorohan Ştefan
Published: March 2009

The research work behind this paper focused a rather extensive assessment of hybrid
composites made of pure aluminium sheets, alternating with GFRP and CFRP layers. Static, fatigue
and low velocity impact tests were performed, combined with NDI on damaged samples, using
Lockin thermography, on specimens obtained from the two hybrid laminates and from genuine
GFRP and CFRP laminates, all having five layers. The static and fatigue tests were made on parallel
specimens, un-notched and having a central 5 mm drilled hole, with various failure modes. The low
velocity impact tests were followed by CAI tests, meant to evaluate residual mechanical
performance and damage tolerance. Lockin thermography was used for prior assessment of damage.
Fatigue Behavior of Non-Crimp Fabrics
Authors: Horst Peter , Adden Stephan
Published: March 2009

The fatigue behavior of non-crimp-fabrics under different multi-axial loading conditions
is presented, using a beneficial characteristic of the material, i.e. the fact that cracks may be detected
by using an optical microscope. This allows to compare two different damage parameters, the crack
density and the stiffness reduction over the life of the specimens.
Fatigue Properties Improvement of Notched Structural Steel Sheets
Authors: Hattori Nobusuke , Nakayama Kazuhiko , Zhang Mian , Nishida Shinichi
Published: March 2009

Nearly 90% of failures of machines and mechanical parts are caused at the area of stress
concentrated in the structural components. Hence, it is important to investigate the method of
improving fatigue strength for notched parts. In this paper, the fatigue tests have been performed to
investigate the effect of the plastic-working on fatigue strength of specimens with notch. The main
results obtained in this study are as follows: (1) The fatigue limit of notched specimen chamfered by
the plastic-working increases by 45% than that of specimen without chamfer. (2) The reason of
enhancing the fatigue strength may be to attributed to the work-hardening and compressive residual
stress which suppress the fatigue crack initiation and propagation in early stage.
Stress Singularity of Thermal Stresses in Three-Dimensional Bonded Structures with an Interlayer
Authors: Koguchi Hideo , Taniguchi Akira
Published: March 2009

In the present paper, singular stress field at the vertex on the interface in
three-dimensional bonded joints is analyzed using BEM and eigen analysis. The order of stress
singularity is determined solving an eigen equation based on FEM formulation and the stress
distribution is expressed using the result of the eigen-value analysis. A relationship between the
thickness of interlayer and residual thermal stresses is presented. Then, a three-dimensional
intensity of singularity is determined.
Reliability Assessment of Corrosion Initiation of Harbor Concrete Structure Using FOSM
Authors: Han Sang Hun , Park Woo Sun
Published: March 2009

Due to the uncertainty of variables in durability model, the probabilistic approach is
increasing. Monte Carlo Simulation (MCS) is an easily accessible method, but requires a lot of
repeated operations. This paper evaluated the effectiveness of First Order Second Moment method
(FOSM), which is more convenient and time saving method than MCS, to predict the corrosion
initiation in harbor concrete structure. Mean Value First Order Second Moment method (MV
FOSM) and Advanced First Order Second Moment method (AFOSM) are applied to the error
function solution of Fick's second law modeling chloride diffusion. Reliability index and failure
probability based on MV FOSM and AFOSM are compared with the results by MCS. The
comparison showed that AFOSM and MCS predict similar reliability indexes and MV FOSM
underestimates the probability of corrosion initiation by chloride attack. Also, the sensitivity of
variables in durability model to failure probability was evaluated on the basis of AFOSM. The
results showed that AFOSM is a simple and efficient method to estimate the possibility of corrosion
initiation in harbor concrete structures.
A Study on the pH Value Changes of Blended Cement Paste According to the Carbonation
Authors: Lee Sang Hyun , Lee Han Seung
Published: March 2009

Life span of structures made with concrete was shortened by carbonation. This phenomenon makes pH in concrete lower. If pH value in concrete become below 10, rebar in concrete begin to be corroded. This pH value was effected by quantity of Ca(OH)2 that depends on cement types, hydration reaction and carbonation time. In this study, pH value and quantity of Ca(OH)2 in mortar which has blast furnace slag were tested according to hydration and carbonation time. As a test result, the more cement has blast furnace slag (BFS) and the longer carbonation time last, the lower pH value in mortar has. And using this quantitative analysis result of pH and Ca(OH)2, it may be used effectively when service life considering carbonation is predicted using FEMA.