bluuebunny/crossref_metadata_2025 huggingface dataset:
The Study of Computer Simulation on Vibratory Metal Machining with Low Frequency
Authors: Song J.L. , Chen Guang Jun
Published: March 2009

Vibratory cutting is one of the newly developed machining techniques and theories in recent years. Insight into the machining mechanism and the chip formation process in metal vibratory cutting has yet to be carried out for this technique to be used widely and efficiently. But with conventional investigation, it is much difficult, and time and energy consuming to analyze and study such principles quantitatively. A system of the computer simulation has been established and based on FEM the chip formation process was emulated. The cutting forces and temperature distribution were imitated under condition of a variety of vibratory frequencies and turning engagements. ANSYS is utilized for the quantitative analysis. Contrast and comparison experiments between vibratory and the conventional metal machining are done, revealing a good agreement between the simulation and the experiment and the inborn nature and the principles of the vibratory metal cutting.
Simulation of Particles’ Activity in Discharge Channel of PMEDM
Authors: Wang Yuan Gang , Zhao Fu Ling
Published: March 2009

Powder mixed EDM can effectively improve the surface quality of a machined
workpiece. In order to study the mechanism of powder mixed EDM process, particles’ activities in
working conditions are simulated and corresponding experiments are done. A 3D electric fields
model described by finite element method of the particles suspended in working fluid in the electric
field is built, the generated field is computed and presented, and the activities of particles in the
breakdown process are analyzed. The results show that this method can serve as a good way to learn
the activities of particles in the breakdown of discharge.
Comparative Analyses on FEM Simulation and Experiment of the Hard Turning Using Chamfered PCBN Tool
Authors: Chen Tao , Wang Yi Wen , Li Yu Fu , Yang C.J. , Liu Xian Li
Published: March 2009

In this paper, cutting experiment and FEM simulation are combined to investigate the effect of various chamfered edge geometries on cutting force and cutting temperature distribution when hardened steel GCr15(HRC60+2) is machined with PCBN tool. The research results indicate that radial force and main cutting force increase with the enlargement of chamfer angle, and especially, radial force rises more significantly, but radial force is less than main cutting force during the entire cutting process. Cutting temperature also gradually rises as chamfer angle increases, and moreover, it is maximized on the chip-tool interface in a place of 0.1-0.2mm distant from nose.
Numerical Simulation of Temperature Distribution during Ceramic Sintering
Authors: Zhang Xiao Feng , Lin Bin , Chen Shi Huan
Published: March 2009

In this paper, the temperature distribution is analyzed during ceramic sintering process and the temperature difference variation is compared under the linear sintering curves with different slopes. Then the changes of temperature difference curve are analyzed under both linear sintering curves and step sintering curves with different slopes. The results indicate that: there are overlap area and platform area in all the temperature difference curves; all the temperature difference curve change from overlap area to platform area; the max temperature difference can not be reduced effectively by applying the heat preservation process at any time; the max temperature difference can be reduced effectively when the heat preservation process is applied at the time of the curve being at the overlap area; the reduction of max temperature difference is small when the temperature difference curve approaches the platform area.
On Saw-Tooth Chip Formation in High Speed Cutting GH4169
Authors: Zhang Dong Jin , Liu Gang , Sun X. , Chen Ming
Published: March 2009

The nickel-based superalloy GH4169 is a typical difficult-to-cut material, but it has been used in a good many kinds of aeronautical key structures because of its high yield stress and anti-fatigue performance at the temperature below 650°C. In this paper, finite element method (FEM) was introduced to study the saw-tooth chip forming process in detail when machining nickel-based superalloy GH4169. By the way of Lagrangian visco-elastic plastic approach, adiabatic shear band (ASB) was simulated in high speed machining condition by general commercial finite element code, and the mechanism of the adiabatic shearing phenomenon at primary shear zone was analyzed with the help of finite element analysis (FEA). The comprehensive comparisons of saw-tooth chip morphology under a wide range of cutting speed were also presented.
Research on Temperature Field of Milling Insert with 3D Complex Groove
Authors: Wu Ming Yang , Meng Q.X. , Liu Qiang
Published: March 2009

Prediction of temperature field is a key technology to achieve the groove design and
reconstruction of milling insert, predictive model of neural network is a new way to achieve the
prediction of temperature field. According to the non-steady state characteristic of temperature field
of milling insert, the paper puts forward a predictive model of temperature field of milling insert
with 3D complex groove based on Levenberg-Marquardt algorithm of BP neural network, and it
overcomes the disadvantage that traditional neural network is easy to fall into local minimum. The
predictive results show that this predictive model can converge quickly and predict accurately.
Investigation of Grinding Process of Particle Reinforced Matrix Aluminium Composites (PRAMCs)
Authors: Li D.P. , Yao Ying Xue
Published: March 2009

In the paper, the experimental study of grinding process of 2024Al/SiCp composites with the electroplated diamond wheel was conducted. The results indicate that the surface roughness of the workpiece is between 0.554 μm and 1.2 μm. Increment of the spindle speed, reduction of the cut depth and decrease of the feed speed make the surface roughness value reduce. After grinding, compressive stresses on the machined surface can be obtained. During grinding, the normal grinding force is greater than the tangent force and the grinding forces increase as the increase of the feed speed and depth of cut.
Elevator Feel and Centering Unit Simulation Based on SimMechanics
Authors: Yang Yu , Cong D.C. , Han Jun Wei
Published: March 2009

The force of control column is very important for the pilot in a flight simulator. So the control loading system in the flight simulator has been concerned since the flight simulator appeared. As the force command signal generated part of control loading system, flight control system module is the most important module for the fidelity of control loading system. This paper described a method to build flight control module. We used SimMechanics in simulink to model and analyze the feel and centering unit, which is the key part of feeling system in the flight control system, and in this paper we described the structure of the control loading system, and the function of the feel and centering unit.
Research on Knowledge-Based Virtual Assembly Planning
Authors: Wang Bin , Liu D.F. , Wang P. , Xie Q.S.
Published: March 2009

In order to find an optimum assembly sequence in engineering design domain, a
knowledge-based virtual assembly approach was put forward. Virtual assembly design environment
was also introduced, and knowledge representation models for virtual assembly rules and cases are
introduced and studied respectively. A side-center virtual assembly method was applied to avoid the
occurrence of assembly interference. Finally, a case was employed to demonstrate the practicality
of knowledge-based virtual assembly planning.
A New Man-Machine Interactive System for Virtual Assembly of Large-Scale Products
Authors: Liu G.H. , Yao Ying Xue , Zhang S.
Published: March 2009

With the analysis of assembly course of some large-scale products, a new man-machine
interactive system for virtual assembly of such products that can realize the operator’s free walking
is put forward. The system architecture and key techniques involved are explored and some
research results in advance are also supplied.
Off-Line Feed Rate Scheduling Using Virtual CNC
Authors: Wu J. , Yao Ying Xue , Li J.G.
Published: March 2009

Maximally utilizing the capabilities offered by the feed drive systems in the CNC
machining can both increase productivity and improve product quality. In this study, a
framework of off-line feed rate scheduling was presented and a turning machining simulation
and feed rate optimal system was developed. The system take advantage of virtual machining
acquires cutting parameters and predicts cutting forces and cutting power. Constant cutting
power was used as an objective to optimize feed rate, the feed rate in NC program was
re-scheduled. The experiment results show that machining time is reduced and machining
stability is improved by using the optimized NC program.
Research on Exact Placement Technology of Virtual Assembly for Large-Scale Products
Authors: Lang Yue Dong , Yao Ying Xue , Xia Ping Jun , Liu G.H.
Published: March 2009

Due to big structure and complex process for some large-scale products (such as planes and rockets), the workers have to try many times and move around in the products to accomplish the assembly operations for high-precision requirements. Thus, the efficiency is low and the cost is high in the assembly process. To deal with that, the virtual assembly (VA) system for large-scale products is developed in this paper. First a new VA environment considering human activity is set up, and then a hierarchical assembly process list (HAPL) model and a dynamic constraint recognition algorithm is proposed to realize exact placement for large-scale products in VA system. Finally, the method is verified by the development VA system which successfully applied in the process of satellite assembly. Moreover, the method can be used in the common VA systems for assembly planning.
Tool Path Simulation Software with Ultra-Precision Grind for Aspherical Elements
Authors: Wang Hui Feng , Wang Guang Lin , Lu Ze Sheng
Published: March 2009

It is very important to improve machining efficiency and ensure manufacture quality
through testing NC program of aspherical elements machining with simulation software. For ultra
-precision NC machining tool, we analyzed the tool path of ultra-precision grind for aspherical
elements, edited a simulation software of the path, got a structural chart of the software, analyzed
some important module of the software. In fact the software is able to imitate tool path, test the
correctness of numerical control code according to numerical control code edited.
Code Translator of STEP-NC Based on ISO14649
Authors: Liu T. , Han Zhen Yu , Wang Yong Zhang , Fu Hong Ya
Published: March 2009

For the application of STEP-NC in NC system, an STEP-NC code translator is exploited. Firstly, summarizes the limitation of conventional standard ISO6983 and the superiority of STEP-NC. After an analysis on two different generating methods of STEP-NC program, introduces the exploited STEP-NC code translator based on ISO14649. According to inner logical relation, the code translator is composed by six functional modules, an operating principle chart is presented, function and realizing method of every module is disserted on. At last, exampled with a program which includes planar face, pocket, slot, Bezier surface and replicate feature of round hole, planning the whole toolpath of the program using extracted information about workingstep, feature and operation by the exploited STEP-NC code translator. A cutting simulation is made to the toolpath and the workpiece model. The result proves the feasibility of the STEP-NC code translator.
Triangular Surface Reconstruction of CT Images by Using Isosurface Construction
Authors: Yang Xiao Dong , Liu Bing Hui , Wang Yang
Published: March 2009

With the development of the modern medical imaging technology and the computer technology, and their interaction as well, rapid prototyping manufacturing, and to design or product a 3D visualized accessory system have become reality. Currently, the information of human body obtained by various medical image equipments such as CT, MRI, is limited to 2D plane image of each layer. In order to ascertain the space relation, size, shape of pathologic body, it will have important theoretic and clinic practical meaning when using computer to take 3D reconstruction and rapid prototyping manufacturing from human organs and pathologic body. Aiming at the key technologies of 3D reconstruction from medical CT images, this paper analyzes and uses the isosurface construction method to construct its 3D models. The paper indicates the shortage of the normal MC algorithm that causes huge consumption of operation and is hard to work out, and applies SMC algorithm to take 3D reconstruction from medical spiral CT images. MC method mainly exists some problems, one is that the triangular facets are only approximate to the isosurface, two is that it is also approximate to connect two close edges’ intersection in the same cube with straight line, next, in the method, if the vertex with 0 value and the vertex with 1 value are at both ends of diagonal line respectively, there will be two kinds of possible connecting methods, thus ambiguity exists [1]. Among a few different methods to judge and eliminate ambiguity, the asymptote method [2] is in common use. Aiming at the shortage of MC algorithm and the characteristics of medical CT images, there is another special MC algorithm called SMC, it connects the triangular facets through estimating state value of each vertex of cube, avoids estimating ambiguity by calculating asymptotic line of hyperbolic curve, simultaneously reduces the calculation to the needless cubes, thereby simplifies the reconstruction method. The SMC method is proved to be simple and effective with two samples in this paper.
Defect Identification and Classification for Digital X-Ray Images
Authors: Yin Ying , Tian G.Y. , Yin Guo Fu , Luo A.M.
Published: March 2009

Radiography inspection (X-ray or gamma ray) is one of the most commonly used
Non-destructive Evaluation (NDE) methods. More and more digital X-ray imaging is used for
medical diagnosis, security screening, or industrial inspection, which is important for
e-manufacturing. In this paper, we firstly introduced an automatic welding defect inspection system
for X-ray image evaluation, defect image database and applications of Artificial Neural Networks
(ANNs) for NDE. Then, feature extraction and selection methods are used for defect representation.
Seven categories of geometric features were defined and selected to represent characteristics of
different kinds of welding defect. Finally, a feed-forward backpropagation neural network is
implemented for the purpose of defect classification. The performance of the proposed methods are
tested and discussed.
Bearing Fault Diagnosis Using Gaussian Mixture Models (GMMs)
Authors: Sun J. , Yu Gang , Li Chang Ning
Published: March 2009

This paper presents a novel method for bearing fault diagnosis based on wavelet transform and Gaussian mixture models (GMMs). Vibration signals for normal bearings, bearings with inner race faults, outer race faults and ball faults were acquired from a motor-driven experimental system. The wavelet transform was used to process the vibration signals and to generate feature vectors. GMMs were trained and used as a diagnostic classifier. Experimental results have shown that GMMs can reliably classify different fault conditions and have a better classification performance as compared to the multilayer perceptron neural networks.
Developing an Internet Based Intelligent Supplier Selection System
Authors: Chen J. , Wu Ming Hong , Barber Patrick
Published: March 2009

E-manufacturing and Global Manufacturing Technologies have been widely employed for the Manufacturing Industry. The supplier selection and evaluation is one of the key events to achieve E-manufacturing and Global Manufacturing Technologies successfully. The paper shows the research work has been done in the university and shows the developed innovational tool for the supplier selection in PC industry.
Research and Realization of Auto-Calibration Technique Based on Structured Grating 3D Measuring System
Authors: Cheng Jun Ting , Zhao C. , He W.T.
Published: March 2009

This paper introduced present application in the world and some problems in the
calibration technique of 3D measuring system. Auto-calibration technique of multiple targets
tracking for detecting outline based on random placement and regular number is put forward. At the
same time, the concrete algorithm is given. Then, according to the algorithm, the corresponding
experimental result is obtained. Furthermore, the calibration accuracy is compared and analyzed.
Finally, it comes to a conclusion that this algorithm can make the operation more simple and
convenient. And the calibration accuracy is kept within 0.03mm.
Hot Affect Region of Base Clad by Laser Beam and its Repeated-Impact Properties
Authors: Shi Shi Hong , Wang Ming Di
Published: March 2009

The experiment result of base of laser cladding samples shows that more energy base
absorb, more wide the Hot affect region. The base with the quenchable material will be quenched
hardening and get refinement organization, such as medium steel, etc. Contrariwise the base of
austenite stainless steel doesn’t have these phenomenons. Under the repeated impact load, the
quenched hardening base may be softened and appear flaw easily, such as crack, etc. The base of
low stiffness may be hardened in a distance.
Modern Data Information Retrieval and an Approach towards Content-Based Collaborative System
Authors: Li L. , Harrison David K. , Lynn John S. , Cheng Kai
Published: March 2009

With the fast deploying and development of information sharing technologies, the Internet has been extensively applied by modern enterprises to pursue a good, efficient communication with their customers and thus research activities supported by global companies zealously motivate onto the Internet which can be used to advertise their products and provide relevant information within design and manufacturing process. Modern enterprises of manufacturing utilize the benefits of global resource from Internet to make the solution which could cut cycle time and reduce costs during the procedure of product design, development and manufacturing. Due to positive development of graphic technologies and 3D modelling tools, Internet is used as an infrastructure to develop new system and explore potential market by modern enterprises on account of the power of sharing text, value and data but also supports dynamic media such as delivering of high quality and interactive 3D graphical content. In the meantime, much work has been done by companies and numerous modelling systems have been developed to build three-dimensional detailed solid which focuses on designing useful parts and shapes using CAD/CAM technologies. Regarding to the increasing quantities of 3D models and requirement of designers based on design reuse in practice, the investigations suggest the achievement of shape data retrieval is viable and a characteristic 3D model search tool is welcome. This paper presents the framework of web-based system and technologies applied in design and the related barrier to implementation is identified. A method for collection 3D data is described and inevitable recursive analysis and relevant equation are induced.
Research on Feature-Based Rapid Programming for Aircraft NC Parts
Authors: Li Ying Guang , Fang T.L. , Cheng S.J. , Liao W.H.
Published: March 2009

Feature-based programming is one of tendency of NC programming technology, and it is also an important portion for CAD/CAPP/CAM integration in the manufacturing enterprises. Because of selecting geometry repeatedly, random programming and bad integration during programming for the aircraft NC parts, the technology of rapid programming based on features is put forward in this paper. On the basis of features, the technology of feature recognition for aircraft NC parts and the algorithm of tool path generation based on features are integrated by taking XML as data transfer standard. With this method, the programming for aircraft NC parts can be realized quickly in the condition of CAD/CAPP/CAM integration. The system developed has been well applied to the programming for aircraft NC parts in an aircraft corporation.
The Influences of Cutting Speed on the Fatigue of Titanium Alloy
Authors: Geng Guo Sheng , Xu Jiu Hua
Published: March 2009

This research is concerned with the influences of cutting speed on the fatigue properties of high speed milled Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy. Four different cutting speeds ranging from 50 to 200m/min were used to mill the specimens for fatigue test, and the fatigue properties of them were studied at two stress levels: 80—800MPa and 90—900MPa. The fatigue lives of the specimens milled under different cutting speeds were compared. The fracture surfaces were analyzed using scanning electron microscope (SEM), and cyclic stress-strain properties of TA15 titanium alloy were investigated with a stress-strain gauge. The results showed that increasing cutting speed can help to improve the fatigue properties of titanium alloy, especially at a relatively low cyclic stress level.
Research on Chip-Breaking Model and Prediction of 3-D Complicated Groove Insert
Authors: Liu E.L. , Han Rong Di , Li Zhen Jia , Zhang Hui Ping , Wei Guo Liang
Published: March 2009

As machining technology develops toward the unmanned and automated system, the
need for chip-breaking control is considered increasingly important. In this paper, chip-breaking
limit of 3-D complicated groove insert is proposed according to cutting experiments. The
mathematical formulation of chip section profile coefficient is established through the analysis of
influential effect of 3-D complicated groove on chip section profile. The chip-breaking model is
developed to predict the critical feed rate and the critical depth of cut in machining based on
analyzing the restricted effect of 3-D complicated groove on chips. Finally, a full experimental
validation of the analytical model is presented for chip breaking when the workpiece is steel, 45.
The testing results show the critical feed rate model and critical depth of cut model are reasonable
and reliable.
A Trust Fine-Grained Access Control Model for ERP System
Authors: Jiang Zhao Liang , Feng Shi Hong , Qi M.F. , Li Zhao Qian
Published: March 2009

In order to protect ERP system information from authorized users or non- trusted users, a
trusted role based access control model was proposed. Combined with the characteristics of
enterprises, trusted computation for user is designed to support roles assignment to the users.
Meanwhile, Object Lifecycle States (OLSs) are presented for efficient access control to objects.
Based on the value of trusted computation, users are assigned the corresponding roles to access
control various resources. Finally, there is an empirical research on an ERP System implemented in
a manufacturing enterprise.
Study on a MEMS CAD System Based on SolidWorks
Authors: Zhang Chang Fu , Lu D.J. , Jiang Zhuang De
Published: March 2009

To enable designers to construct geometric models of MEMS devices in a straightforward environment and get mask and process flow automatically, a 3D MEMS CAD system for surface micromachined devices is proposed based on traditional design software—SolidWorks. With Application Programming Interfaces (APIs) of SolidWorks, component modules and databases of the system are developed with Visual Basic, such as geometric model design module, mask and process flow generation module, process simulation module, 3D feature database and material database. Their development method is discussed in this paper. A practical example shows that surface micromachined devices can be designed efficiently in the system without tedious fabrication process.
A Framework of a NC Program Translator for Virtual Machining
Authors: Gao Dong , Yao Ying Xue , Lee Wing Bun , Cheung Chi Fai
Published: March 2009

Virtual manufacturing (VM) is an emerging technology that provides a digital tool for the
optimization of the production efficiency through simulations prior to the start of actual production.
A NC program translator is one of the crucial components for virtual machining which allows the
simulation and verification of NC tool path before actual machining. In this paper, a framework of a
NC program translator for diamond turning of precision optics is presented.
Model Research on Special Metal Cutting NC Machine Tool
Authors: Zhao Tong , Ye P.Q. , Zhang H. , Wang X.K.
Published: March 2009

In this paper the model of special metal cutting NC machine Tool is presented, which
consists of a base module, an overall control module, particular functional modules as well as a
relation module. Each module involved in aforementioned model will be composed by software,
hardware and mechanical parts, so as to combine the convergence of the ideas of modularization
and mechanical-electrical integration into current understanding of special NC machine tool
through the proposed model. Specially, the relation module is introduced to deal with the linking
among all the other modules. The presented model aims to broaden the perspective of machine
designers intending to increase the efficiency in machine design. By giving the so-called function
unit model a novel modeling approach is delivered to carry out control research of special metal
cutting NC machine, which is followed by the formalization description method presented as a
possible abstraction methodology towards the efficient description and identification of special
metal cutting NC machine tool.
Study of Knowledge-Based Engineering (KBE) Technology for the Cutting of Large Containers
Authors: Chen Yu Quan , Li Zhen Jia , Guo Jin Xing , An A.M.
Published: March 2009

The combination of metal cutting theory, computer technology and expert knowledge
was used to study the use of knowledge-based engineering (KBE) for cutting large containers. This
report includes information on the acquirement, expression, and inference and management of
KBE. The structure of the KBE system was established by selecting the principles of processing
parameters and optimizing the model of machining data and by using the method of expressing
knowledge of combining producing type with frame type and by using the software SQL server
2000. The inferential mechanism of every functional module in the system was realized by applying
the software, VC++ 6.0. The KBE technology will help technicians to share expert knowledge and
experience, and to optimize cutting parameters to intellectualize cutting design and machining.
Research on Material Removal Algorithm Model in Virtual Milling Process Based on Adaptive Dynamic Quadtrees Algorithm
Authors: Wang Wen Jin , Wang Tai Yong , Fan Sheng Bo , Wang W.Y.
Published: March 2009

The realistic dynamic image of virtual milling process is important in the field of virtual
manufacturing technology. However, it is difficult to realize virtual 3-D workpiece model removing
process. Material removal algorithm model based on an adaptive dynamic quadtrees algorithm is
proposed in this paper. Based on mathematical model of virtual material removal, the 3D model of
virtual CNC milling process was developed. The real-time simulation of material removal process
was realized in the virtual reality environment.
Probe on Multi-Agents Collaborative Commerce System Embedded with E-Maintenance
Authors: Chen Xiao Hui , Sheng Tian Wen , Yi Shu Ping
Published: March 2009

Currently, manufactures pay more attention to customers’ needs and service than products only. In order to quick response to the customer requirements, the Collaborative Commerce (CC) System was developed to support the collaboration work flow and organization of all of the partners of the enterprises which include the after sale service. With the fast developing of the advanced information technology, maintenance technology was embedded with web technical and intelligent technology, that is E-maintenance. Since traditional CC system could not able to support after-sale maintenance service for lack of advanced maintenance service platform. In the paper, a new Collaborative Commerce System embedded with E-maintenance (Em-CC) was proposed. The framework of Em-CC System with multi-agents consideration was introduced, and the enabling technologies and operation mode of E-maintenance subsystem were explained in detail. Finally, an practice example was presented to demonstrate the validity of the system.
The Development of Virtual Machining System Based on ACIS
Authors: Wu J. , Yao Ying Xue , Li J.G.
Published: March 2009

The NC machine tool is widely used in today's manufacturing industry. In this paper, a
framework of the NC lathing dynamic simulation system is presented and the machining process
simulation is developed based on the solid modeling method with ACIS geometric engine and 3D
graphic display. The tool swept volume is designed and Boolean difference of the cutter swept
volume with the raw stock in the system is calculated. The user or trainee can practice all operations,
procedures and skills in complete safety, while maintaining a high degree of realism.
Three-Dimensional Finite Element Analysis on Precision Cutting for Tool with Nose Radius Considering Tool Edge Radius
Authors: Zhai Yuan Sheng , Liang Ying Chun , Bai Qing Shun
Published: March 2009

The finite element modeling and experimental validation of three-dimensional precision
cutting of 3J33 maraging are presented. The commercial software MARC applied for the finite
element modeling is studied the effect of tool nose radii considering tool edge radius on the
principal cutting forces and the temperature fields. The model employs an updated Lagrangian
formulation. The friction between the tool and the chip is assumed to follow a modified Coulomb
friction law and the adaptive remeshing technique is using for the formation of chip. The tool edge
radius significantly affects the cutting forces and the maximum temperature of the chip. The
simulation results for tool with nose radius considering tool edge radius are compared with
experimentally measured data and found to be in good agreement.
Emissivity Calibration and Research of Infrared Image Processing in the Cutting Temperature Test
Authors: Wang Yi Wen , Hao Huan Rui , Liu Xian Li , Yue Cai Xu
Published: March 2009

It is by the emissivity of the goal objects and the noise problem of the high temperature images that people are puzzled during the course of the cutting temperature tested by the application of thermal imaging device. By using thermocouples, and getting the comparison of thermocouples and the thermal imaging system temperature, we calibrate object emissivity, handle the image noise by improved median method, carry on the edge extraction of image, obtain the temperature of measured objects, and finally confirm the accuracy of the data got by the thermal imaging device with contact measurement.
Locating and Classifying Defects with Artificial Neural Networks
Authors: Luna Avilés A. , Hernández-Gómez Luis Héctor , Durodola J.F. , Urriolagoitia-Calderón G. , Urriolagoitia-Sosa G.
Published: March 2009

Locating defects and classifying them by their size was done with an Adaptive Neuro
Fuzzy Procedure (ANFIS). Postulated void of three different sizes (1x1 mm, 2x2 mm and 2x1 mm)
were introduced in a bar with and without a notch. The size of a defect and its localization in a bar
change its natural frequencies. Accordingly, synthetic data was generated with the finite element
method. A parametric analysis was carried out. Only one defect was taken into account and the first
five natural frequencies were calculated. 495 cases were evaluated. All the input data was classified
in three groups. Each one has 165 cases and corresponds to one of the three defects mentioned
above. 395 cases were taken randomly and, with this information, the ANN was trained with the
backpropagation algorithm. The accuracy of the results was tested with the 100 cases that were left.
This procedure was followed in the cases of the plain bar and a bar with a notch. In the next stage of
this work, the ANN output was optimized with ANFIS. The accuracy of the localization and
classifications of the defects was improved.
A Neural Network Approach for Locating Multiple Defects
Authors: Farley S.J. , Durodola J.F. , Fellows N.A. , Hernández-Gómez Luis Héctor
Published: March 2009

A method is presented to demonstrate the use of artificial neural networks (ANNs) in
providing additional information regarding defects or flaws when used in conjunction with the
ultrasonic A-scan method. ANNs were employed both as pattern classifiers and as function
approximators to maximise the amount of data available from the temporal A-scan signal. A steel
bar was modelled in 2D using ABAQUS finite element analysis (FEA) software. A single defect
was introduced to the bar, modelled as a void, and parametric studies conducted to record data with
the defect at various locations. An ultrasonic Lamb wave was introduced at the top of the bar. The
longitudinal wave propagated along the length of the bar and was partially reflected by the defect.
Multiple cases were simulated, modelling voids between 1mm and 6mm in width in various
locations. Mean displacement of all the nodes at the top of the bar was recorded throughout the
simulation, and features extracted from this waveform to create the data set for the ANNs. The
ANNs were trained with a percentage of the data collected, selected at random, and assessed with
the remaining data. The target data for the ANNs were the depth and size of the defect. The case of
two separate defects was also investigated. The procedure was carried out in the same manner as for
one defect, but in this case the target data for the ANNs were the depth of the first defect and the
distance between the defects. A separate ANN was employed as a pattern classifier, to determine if
the reflected A-scan signal represented one or two defects. The final system was tested using
previously unseen data, and provided very good results both in determining the number of defects
and the size and location of the defects, even with data to which noise had been added.
Plastic Deformation Quantified by Atomic Force Microscopy Measurements for Duplex Stainless Steel under Monotonic and Cyclic Loading
Authors: Serre Ingrid , Salazar Daniel , Vogt Jean Bernard
Published: March 2009

By atomic force microscopy, the plastic deformation marks resulting from monotonic and
cyclic plastic deformation were analysed to study the plasticity in each phase of Duplex Stainless
Steels. In austenite, straight slip bands were observed after monotonic loading. These straight slip
bands seem to serve as fatigue extrusion nucleation sites, which are the marks of the
accommodation of the cyclic plasticity by the austenite. In ferrite, after monotonic loading, slip
bands, could be classified into two different groups depending on whether they result from the bulk
activities of ferrite or whether their formation is assisted by the plastic deformation of austenite. It
was found that the crystallographic misorientation based on a Kurdjomov-Sachs relationship is the
factor controlling one or the other type. After the first 5 loading cycles, the ferrite presents only
monotonic plastic marks. This suggests no direct contribution of the ferrite to the accommodation of
the cyclic plasticity.
Numerical Evaluation of the Crack Compliance Method (CCM) in Beams with and without Prior History
Authors: Urriolagoitia-Sosa G. , Urriolagoitia-Calderón G. , Sandoval Pineda J.M. , Hernández-Gómez Luis Héctor , Merchán-Cruz E.A. , Rodríguez-Cañizo R.G. , Beltrán-Fernández Juan Alfonso
Published: March 2009

This work assesses the Crack Compliance Method (CCM), which has been extensively
used for the experimental evaluation of residual stresses, by the Finite Element Method (FEM) to
validate its experimental applicability through numerical evaluation. The CCM is a very powerful
method that is based on Fracture Mechanics theory, but its experimental application and set up has
not been totally scientifically validated. In this paper, a numerical evaluation is presented on the
basic applications of the CCM. The assessment of the CCM is performed on bending beams with
and without prior straining history. To determine the best position and orientation of the strain
gages, as well as the optimum number of readings, a number of numerical simulations where also
performed for the correct performance of the experimental evaluation of the CCM. The prior
straining history condition, in the analyzed components, is induced by an axial pulling before the
beam is bent. Three levels of preloading are considered: low, medium and high (which are related to
the yield strain of the simulated material); Isotropic and Kinematic hardening rules are also
considered. After the residual stress field is induced by bending, a slot cutting is simulated and the
strain relaxation produced is captured, which is used later in the CCM program for the
quantification of the original residual stress field. The results obtained in this work, provide a
quantitative demonstration of the effect of hardening strain on the distribution of the residual stress
in beams. In the same manner, the theoretical formulation of the CCM has been evaluated
validating the application of this method for the determination of residual stress fields in mechanical
components.
Detecting and Identifying Artificial Acoustic Emission Signals in an Industrial Fatigue Environment
Authors: Hensman James J. , Pullin Rhys , Eaton Mark J. , Worden Keith , Holford Karen M. , Evans S.L.
Published: March 2009

This paper details progress towards the application of a methodology for
Acoustic Emission (AE) detection and interpretation for the monitoring of fatigue fractures
in large-scale industrial environments. An artificial acoustic emission source, representative
of a fatigue fracture was injected into a test of a substantial landing gear
component. An AE monitoring system was then used to successfully locate and identify
the source using the new signal processing methodology.
Buckling by General Instability of Cylindrical Components of Deep Sea Submersibles
Authors: Ross Carl T.F. , Okoto K.O. , Little Andrew P.F.
Published: March 2009

This paper reports on theoretical and experimental investigations into the buckling characteristics
of a series of six ring-stiffened circular cylinders that experienced general instability when
subjected to external hydrostatic pressure. Each study used between 3-5 designs with the same
internal and external diameters, but with different numbers and sizes of ring-stiffeners. Four used
designs that were machined to a high degree of precision from steel, while the other two were
machined from aluminium alloy.
The theoretical investigations focused on obtaining critical buckling pressure values, namely Pcr,
for each design from the well-known Kendrick’s Part I and Part III theories, together with an
ANSYS finite element prediction. The thinness ratio λ1, which was originally derived by the
senior author, was calculated together with a dimensionless quantity called the plastic knockdown
factor (PKD), for each model. The plastic knockdown factor was calculated by dividing the
theoretical critical buckling pressures Pcr, by the experimental buckling pressures Pexp. The
thinness ratio was used because vessels such as these, which have small but significant random
out-of-circularity, defy “exact” theoretical analysis and it is because of this that the design charts
were produced.
Three design charts were constructed by plotting the reciprocal of the thinness ratio (1/ λ1)
against the plastic knockdown factor (Pcr / Pexp), using results from Kendrick Part I, Kendrick Part
III, and ANSYS. Comparison of the results obtained using Kendrick’s theories and
experimentally obtained results was good.
A Signal to Noise Optimization Algorithm for Speckle Interferometry Applications
Authors: Molimard J. , Cordero R. , Vautrin A.
Published: March 2009

Optical Full Field Techniques (OFFT) are more and more utilized by mechanical
laboratories. Among these methods, interferometry techniques (mainly composed of
Speckle/Grating Interferometry or Speckle/Grating Shearography) are more difficult to use in a
mechanical lab context, because of their sensitivity to external vibrations (except shearography),
and because of the global lack of optical culture of mechanical engineers. Speckle-based methods
are of great practical interest for the users, but their signal to noise ratio (SNR) is affected by the
rigid body motion of the specimen. Here, the speckle decorrelation is minimized at local scale
directly using the SNR. First, a shearography experiment is modeled to characterize the
recorrelation procedure for a rigid body motion, a constant strain map and finally a high degree of
localization. The mean noise level is found to be 6 times higher than a fully-correlated phase map
for a 1 pixel speckle size. Last, a first application to a single-ply fabric composite lamina is shown.
Resulting strain maps are of high quality with a very low spatial resolution (4 pixels). The local
bending / global tension coupling effect is clearly put in evidence.
A Study of Stress Analysis for a Residual Stress Model by Digital Photoelasticity
Authors: Kihara T.
Published: March 2009

The stress analysis for a model with initial stresses, which we term a residual stress
model, is performed by digital photoelasticity. The stresses applied on the residual stress model are
obtained by analyzing both the initial stresses and the resultant stresses. The method used for
analyzing the stresses applies the principle of superposition of the stress to photoelasticity, which is a
well-known technique in the field of elasticity. In the digital photoelasticity technique used, the
principal stress direction and the relative phase retardation  are analyzed by photoelastic
techniques using linearly polarized light. This technique overcomes the phase difference error
associated with a quarter-wave plate by employing incident light at three different wavelengths, and
using an unwrapping technique that allows and  to be determined using the arctangent function.
A residual stress model produced by a disk containing frozen stresses that was subjected to a
diametral compressive load at an angle of 31 was used to experimentally test this method. The
values of the stresses of the loaded disk model analyzed were in good agreement with corre- sponding
theoretical values at all locations far from the loading points of the residual stress model.
Introduction to the Characterization of Hygrothermal Microcracking of Crossply Composites Reinforced by Stitched Non-Woven UD Laminae
Authors: Liotier P.J. , Vautrin A. , Beraud Jean Marc , Henrat Patrick
Published: March 2009

This article presents a first approach of hygrothermal microcracking in stitched crossply
laminates. The presentation includes the definition of the material mesostructure and the selection
of a characterization method adapted to the specificity of the study. The hygrothermal loading
selected is discussed and the evolution of the crack density in stitched crossply composites during
the loading is presented and commented.
Material Properties for Quantitative Thermoelastic Stress Analysis of Composite Structures
Authors: Frühmann R.K. , Sambasivam S. , Dulieu-Barton Janice M. , Quinn S.
Published: March 2009

The sensitivity of the thermoelastic response to variations in the fibre volume fraction,
resin material and manufacturing route is assessed. To quantify any effects a comprehensive
materials testing programme has been conducted to obtain coefficients of thermal expansion,
specific heat, density and the elastic properties, which is described in detail in the paper. The work
is focused on attempting to ascertain if the source of the response is from the isotropic resin rich
layer or from the orthotropic substrate. It is also demonstrated that small variations in material
properties can have a significant effect on the calculated thermoelastic response.
The Application of Fine Increment Hole Drilling for Measuring Machining-Induced Residual Stresses
Authors: Grant Paul , Lord Jerry , Whitehead P. , Fry A. Tony
Published: March 2009

Hole drilling is one of the most widely used techniques for measuring residual stress, but the conventional approach is limited in the near surface detail that can be resolved. Because of concerns about the levels of induced residual stress that might develop during machining and surface treatment processes, there is significant interest in developing a technique that can obtain near-surface residual stress information by the application of fine-increment hole drilling. Critical information can be lost if conventional, large depth increments are used and the fine incremental hole drilling approach, using depth increments as small as 20µm, offers a cost effective and rapid solution, with the possibility of measuring near surface stresses. Results focus on three different machining studies and a shot peened specimen, all cases where the stress field changes rapidly through the depth, particularly close to the surface. A systematic assessment of machining parameters is not within the scope of this paper and is not presented, but work has focused on highlighting the application and potential of the fine increment hole drilling approach.
Residual Stresses Prediction for CO2 Laser Butt-Welding of 304-Stainless Steel
Authors: Benyounis Khaled Y. , Olabi Abdul Ghani , Hashmi M.S.J.
Published: March 2009

Residual stresses are an integral part of the total stress acting on any component in service. It is important to determine and/or predict the magnitude, nature and direction of the residual stress to estimate the life of important engineering parts, particularly welded components. This work aims to introduce experimental models to predict residual stresses in the heat-affected zone (HAZ). These models specify the effect of laser welding input parameters on maximum residual stress and its direction. The process input variables considered in this study are laser power (1.03 - 1.368 kW), travel speed (26.48 – 68.52 cm/min) and focal point position (- 1 to 0 mm). Laser butt-welding of 304 stainless steel plates of 3 mm thick were investigated using a 1.5 kW CW CO2 Rofin laser as a welding source. Hole-drilling method was employed to measure the magnitude, and direction of the maximum principal stress in and around the HAZ, using a CEA-06- 062UM-120 strain gauge rosette, which allows measurement of the residual stresses close to the weld bead.
The experiment was designed based on Response Surface Methodology (RSM). Fifteen different welding conditions plus 5 repeat tests were carried out based on the design matrix. Maximum principal residual stresses and their directions were calculated for the twenty samples. The stepwise regression method was selected using Design-expert software to fit the experimental responses to a second order polynomial. Sequential F test and other adequacy measures were then used to check the models adequacy.
The experimental results indicate that the proposed mathematical models could adequately describe the residual stress within the limits of the factors being studied. Using the models developed, the main and interaction effect of the process input variables on the two responses were determined quantitatively and presented graphically. It is observed that the travel speed and laser power are the main factors affecting the behavior of the residual stress. It is recommended to use the models to find the optimal combination of welding conditions that lead to minimum distortion.