bluuebunny/crossref_metadata_2025 huggingface dataset:
Friction Stir Processing (FSP) of As-Cast AA5083 for Grain Refinement and Superplasticity
Authors: Hayashi J.T. , Sarath Menon E. , Su J.Q. , McNelley Terry R.
Published: February 2012

Multi-pass FSP was conducted on continuously-cast (CC) AA5083 materials in the as-cast condition. Stir zone grains were refined to ~1.0 – 3.5μm in size and highly superplastic response was obtained during tension testing of the as-processed materials at 450°C (>1200 pct. elongation at 10-1 s-1). Current models of recrystallization do not predict adequately the highly refined grains and predominantly random textures that are observed in stir zones. Grain refinement during FSP is accompanied by refinement and redistribution of non-deforming constituents in the absence of particle fracture. The mechanics of the homogenization process remain to be established and requirements for redistribution mechanisms will be summarized. Comparison reveals that results from FSP of the as-cast material are superior to those attained in conventional processing.
Elevated Temperature Fabrication of Titanium Aerospace Components
Authors: Hefti Larry D.
Published: February 2012

In the past, engine aft fairing heat shields have typically been titanium castings. With a current single aisle airplane, these components were converted to sheet metal titanium 6Al-4V details fabricated by hot forming or Superplastic Forming (SPF). This conversion saved approximately 20% in both cost and weight per airplane. When heat shields for a twin aisle airplane were being developed, the engineers were interested in a sheet metal version of their heat shields hoping to achieve similar savings. However, the twin aisle configuration was different from the single aisle and did not allow the details to be simple pieces of formed sheet metal. Instead, these twin aisle heat shields are assemblies of details containing SPF components as well as Superplastically Formed and Diffusion Bonded (SPF/DB) panels. Some of the heat shield components are fabricated using the world's first applications of fine grain 6Al-4V titanium, which was developed to SPF at 775°C, covered by a U.S. patent [1], instead of 900°C, which is used for standard grain material. The SPF/DB technology being used contains innovative process developments that are covered by several patent applications [2-4]. The twin aisle heat shield assemblies were estimated to save approximately 15% in both cost and weight per airplane. Actual weight measurements of the first assembly showed an additional 5% savings over the calculated weight per engine resulting in a total weight savings of approximately 20% per airplane compared to titanium castings.
Study on Multi-Track Wireless Communication and Laser Detection Device over the Line
Authors: Ding Shou Cheng , Li Wen Hui
Published: February 2012

This paper studied the transmission of the athletics starting signal and the end signal detection over the line in track and field competition. At the starting point, 433MHz wireless transmitter module coded and sent the start signal. In the race finish line, the laser device detected athletes signal over the line. The system used an embedded Microsoft Visual Basic 6.0 serial communication control to achieve a reasonable upper and lower computer hardware and software online. Experiments show that: The combination system of hardware and software control applies wireless communication technology and laser detection devices to avoid interference with normal visible light. It has many advantages of a timing accuracy, fast and accurate arrangement of athletes.
Development of Microwave Limb Sounder
Authors: Zhao Yue Feng , Li Jing
Published: February 2012

Microwave limb sounding is powerful to measure atmospheric compositions, temperature and pressure with high vertical resolution. During the past few decades many countries have developed several Microwave limb sounders to improve our understanding of stratospheric ozone chemistry and dynamics, the interaction of composition and climate and pollution in the upper troposphere. This issue will outline five existed MLS instrument and analyze their adopted techniques for lower noise and higher sensitivity as well as their capabilities comparisons. In American, the Jet Propulsion Laboratory (JPL) has already developed three MLS instruments: the UARS-MLS, EOS-MLS and CAMEO-SMLS which is ready for launch in 2011. In Japan, its JEM/SMILES is the first MLS instrument to use superconductor-insulator-superconductor (SIS) mixers with a mechanical 4-K refrigerator in space. In Sweden, the millimeter and sub millimeter limb-emission sounder on Odin uses actively cooled Schottky receivers with auto-correlators and wide hand AOS.
Research and Design of the Control System for Vibratory Stress Relief Based on Virtual Instrument
Authors: Meng Jian Jun , Zhang Can Can , Tong Yu Qi , Wang Chao , Jin You Juan , Qi Wen Zhe
Published: February 2012

This paper proposes the method of multi-point VSR control system based on virtual instrument for the single-point aging cannot meet the problem of eliminating large and middle-sized the residual stress of workpieces. The system could achieve the setting of parameters on stress relief and the automatic controlling of the work process on PC by using LabVIEW as the development platform. By using data acquisition card USB-6229 BNC, it can realize the output voltage and the frequency pulse and the collection on the acceleration by the way of real-time and frequency variation sampling. At the same time, it has provided the theoretical basis for the effect of vibratory stress relief, and the system has realized the design and test in the laboratory, compared with the development method of single-point vibratory stress relief, this system has many advantages, such as the shorter aging cycle, the effect of eliminating residual stress and so on.
Band Selection Oriented to Easy-Confused Objects for Classification of Hyperspectral Imagery
Authors: Zhao Xin , Li Xing
Published: February 2012

As a dimensionality reduction technique, band selection is an importance pre-processing step for classifiers. In this paper, a band selection approach oriented to easy-confused objects for classification of hyper spectral imagery is presented. Firstly, an Objects Confusion Index (OCI) is established to ascertain the easy-confused objects. Then the two band selection schemes, that are two-class mode and multi-class mode, are designed by adopting Bhattacharyya distance as class reparability measure.
Pattern Recognition of Carbonate Rocks in Rs Image
Authors: Kuang Hong Hai
Published: February 2012

Pattern recognition of carbonate rocks in RS image have been studied in the paper. Samples of carbonate rocks were scanned into rock images.By analysing these samples of carbonate rocks,a new arithmetic was chosed and a standard curve of carbonate rocks by the arithmetic can be gotten.Rs images were divided into grids.There are curves by the arithmetic in grids. The standard curve of carbonate rocks and curves in grids were compared.If both of curves look very similar,the grid is carbonate rocks area.
Classification of Hyperspectral Data Based on Semi-Supervised Tri-Training Learning Framework
Authors: Huang Rui , Zhou Li Na
Published: February 2012

A semi-supervised learning framework based on the tri-training scheme is proposed for the classification of hyper spectral data. The framework involves two stages: multiple classifier learning by the improved tri-training and integrating the outputs of classifiers to the final hypothesis by decision fusion. To settle the ill-posed classification problem, in the stage of classifier learning, the label confidence of each learner is measured by the improved estimation of classifier error, and self-training is introduced to expand the labeled set using unlabeled samples with confident labels assigned by classifiers. Hyper spectral data classification experiments show the effectiveness of the proposed framework.
Mechanical-Condition Assessment of Power Transformer Using Vibroacoustic Analysis
Authors: Kornatowski Eugeniusz
Published: February 2012

This paper presents a method for vibroacoustic analysis of a transformer in the steady state. The standard approach to this problem has been based on analysis of the vibration frequency spectrum recorded with an accelerometer mounted on the transformer’s tank. To improve legibility of measurement results, the paper suggests the analysis method for the relative coefficient of harmonic frequency contents hnorm(f). The conducted experiment showed that high values of hnorm within a wide frequency range testify to deformation of windings and degradation of solid insulation.
A Non-Iterative Algorithm to Determine Camera Position and Orientation
Authors: Zeng Huai En , Yi Qing Lin , Zheng Yi
Published: February 2012

Determination of Camera position and orientation is a basic research subject in photogrammetry and computer vision. This paper introduces a new explicit approach to determine the camera-point distances based on the computer algebraic software of Matlab, then derives the basic mathematic model of pose estimation, and puts forward the analytical calculus of rotation matrix based on the Gibbs vector or Rodrigues matrix, finally presents explicit formulae of camera orientation and position. A simulative case is studied, and the result shows the presented algorithm is correct and efficient for arbitrary pose angles image.
Simulating and Mapping the Variations of Solar Radiation at the Lujiazui Region of Shanghai Using Airborne LiDAR Data
Authors: Hu Zhi Ming , Wu Jian Ping , Wu Bin , Shu Song , Yu Bai Lang
Published: February 2012

This study utilizes high resolution airborne LiDAR data and topographic solar radiation model to quantify the impacts of three-dimensional morphology on the spatio-temporal variations of solar radiation at the Lujiazui Region, Shanghai, China. Monthly direct and non-direct (diffuse and reflection) plus seasonal total solar radiation distributions are simulated and mapped by using a radiation flux model. The results show that the crowded buildings at the Lujiazui Region have severely changed the spatial pattern of solar radiation intensity and duration. The derived monthly and seasonal solar radiation maps would benefit the understanding of the impacts of urban 3D morphology on the environmental factors and be the scientific basic for the further research.
Sar Image Denoising Based on Multifractal and Regularity Analysis
Authors: Chen Yun Ping , Chen Yan , Tong Ling
Published: February 2012

Synthetic Aperture Radar (SAR) images are corrupted by multiplicative speckle noise, which is due to random interference of electromagnetic waves. The noise degrades the quality of images and makes them hard to be interpreted, analyzed and classified. It appears sensible to reduce speckle in SAR images, while the structural features and textural information are not lost. This paper applies the framework of multifractal and regularity analysis to SAR image enhancement and denoising. The method does not make explicit assumptions about the model of the noise, but rather supposes that image denoising is equivalent to increasing the Hölder exponent at each point. The image is characterized via its multifractal spectrum, which mode yields the most frequent Hölder exponent. This manipulation leads to a smooth image while preserving the useful information in the signal. In order to evaluate the restoration result, Equivalent Number of Look (ENL) and edge save index (ESI) are used as criterion. Better result is obtained when regularity increase equal 0.5 (δ=0.5).
Incremental Study Based on Support Vector Used to Anomaly Detection for Hyperspectral Imagery
Authors: Zhang Li Yan , Chen De Rong , Sun Yong Hua
Published: February 2012

While detecting anomalies in hyperspectral imagery with support vector data description (SVDD), large numbers of operation was run because of the high dimension character of dataset and the complexity of background and the high miss rate was discovered because of the interfered background by interior anomalies. This paper used incremental support vector data description (ISVDD) method that samples are divided many sub-sample, and incremental study is designed to simplify the computation. On every sub-sample study, optimization is needed according of the support vectors obtained from above sub-sample and current sub-sample data. By the experiment on the HYMAP data, computation complexity of the algorithm decrease obviously and the computation speed increase highly under the similar detection effect compared with SVDD algorithm.
Comparative Study of Thermal Degradation Behavior of High Char Yield Phenolic Resin and Commercial Resin
Authors: Chen Zhi Qin , Zeng Wei Jun , Chen Yang Fei , Li Wen Kui , Liu Hong Bo
Published: February 2012

The thermal degradation behavior of high char yield phenolic resin (PF1.2) synthesized by us was investigated, in comparison with that of commercial resin (PF1.5), using TGA and13C-NMR techniques. It was found that the degradation process of PF1.2behaved very similar to that of PF1.5during heat treatment up to 700 °C under N2atmosphere, but resulted in a somewhat different extent of some specific reactions. That was, although the reactions occurring up to 700 °C were dominated by crosslinking and/or polyaromatization, fewer methyl bonds from breaking of methylene bridges were formed in PF1.2than in PF1.5. As a consequence, a higher char yield of 73.8% of PF1.2than that of PF1.5(57.5%) up to 700 °C under N2atmosphere was attached, with better thermal properties.
Resin-Based Truss Composite Materials and its Preparation Process
Authors: Yang Wei Min , Wang Yang , Li Shu Jiang
Published: February 2012

In this paper, we propose a resin-based composite materials and its preparation process, because traditional composite materials craft has shortcomings such as labor-intensive, low productivity and quality unstable. It can eliminate the need for mold processing and manufacturing sectors, and the manufacturing costs reduce significantly. Reinforcing materials can play a full role to enhance, and the volume of products can be great without the restrictions of traditional processing equipment. The speed of product replacement is accelerated.
The Study of Electroless Ni-B Coating on 45 Steel
Authors: Guo Jian Zhang , Liu Qian
Published: February 2012

In order to improve the corrosion resistance and the hardness of the 45 steel, under comparison tests, the electroless Ni-B was prepared on the 45 steel. We made a contrast test to get the optimal formula. The coating under the optimal formula was characterized by Scanning Electron Microscopy(SEM), Energy Dispersive Spectrometer(EDS), metallurgical microscope and salt spray cabinet. The experimental results showed that the electroless Ni-B coating on 45 steel was low boron coating, with high hardness, and the hardness of the coating could catch HV524; the thickness of the coating was 16μm.
Effect of Die Structure on Radial Orientation of Short Fiber in Tire Tread and its Performance
Authors: Zhang De Wei , Wang Chuan Sheng , Lin Guang Yi , Li Shao Ming , Chen Chun Ping
Published: February 2012

Extrusion and molding is one of the most important manufacturing processes of short fiber-rubber composite material. In order to be used to tire tread, the short fibers in rubber are wanted to be radial orientated. But the orientation of short fibers depends on the die structure, and the performances of short fiber-rubber composite material depend on the radial orientation degree of short fibers. So, the die structure has been studied by experiments in order to get a proper die structure for manufacturing of short fiber-rubber composite material. The experimental results indicate that the proper die structure parameters are: the molding length is 15mm, the molding height is 9mm, the channel length is 75mm, the channel height is 12mm and the channel angle is 135º.
The Binding Performance of Erythromycin Imprinted Polymeric Microspheres
Authors: Guan Ping , Hu Xiao Ling , Zhu Li
Published: February 2012

Erythromycin molecularly imprinted polymeric microspheres（EM-MIPMs) which have good shape and well-distributed size were prepared by suspension polymerization in aqueous phase, using EM as a template and methacrylic acid (MAA) as a functional monomer. The size of MIPMs is about 50.17 μm characterized by laser particle size analyzer and polarizing microscope. The interaction between the template and monomer, and selective binding performance were investigated by ultraviolet spectrum analysis, equilibrium binding experiments and Scatchard analysis. The results show tha t hydrogen bonding may contribute to the interaction between EM and MAA, EM-MIPMs demonstrated much higher adsorption capacity compared with the NMIPMs. It has also been found that there are two kinds of binding sites in EM-MIPMs and only one kind in NMIPMs.
Research on Vulcanization Process of Short Fiber-Rubber Composite Material
Authors: Wang Chuan Sheng , Zhang De Wei , Guo Lei , Zeng Xian Kui , Wang Xiao Bo , Li Li
Published: February 2012

Vulcanization process is the last step of manufacturing rubber products. For tire tread which is made of short fiber rubber composite material, vulcanization is complex due to during vulcanization process the flow of mixed rubber maybe change short fibers orientation. As a result, during vulcanization process, several pieces of iron wire have been put in the mold to play the role of tire patterns for the first step research. The experimental results indicate that the flow of mixed rubber would not change short fibers orientation greatly, and physical and mechanical properties of short fiber-rubber composite material keep as good as that vulcanized without iron wire.
Study on the Submarine Pipeline with Flexible Spoilers
Authors: Han Yan
Published: February 2012

Two new methods which use flexible spoilers to protect submarine pipelines are proposed. One is put flexible spoiler on the top of the pipe to make pipe self-buried. The other is put flexible spoiler under the pipe to stop the erosion under the pipe. Through physical experiments, the pressure distribution and scour hole around the submarine pipeline with flexible deflectors were studied. Experiment results point out that top flexible spoiler can increase the resistance of the pipe, increase the scour hole depth, accordingly make the pipeline be self-buried. The flexible spoiler under the pipe can reduce the pressure difference between both sides of the pipeline, diminish the scour hole depth obviously and even to stop scour.
Optimize Mixing Process Parameters of Synchronous Rotor Mixer Based on Orthogonal Method
Authors: Fu Ping , Bai Feng Bao , Wang Chuan Sheng , Li Shan Hu
Published: February 2012

In this paper adopting the orthogonal method, self-developed compound formulation had tested, and the relationship between the physical properties of vulcanized rubber and rectangular synchronous rotor mixer parameters had researched. The results showed that when the fill factor was 0.6, the rotor speed was 70r/min, cooling water temperature was 45 °C, pressure on the top bolt was 0.8Mpa, the physical properties of the vulcanized rubber was best.
The Finite Element Analysis of Steel Cord in Radial Tire’s Belt Ply
Authors: Li Li , Wang Yun
Published: February 2012

The belt ply plays an important role in the performance of radial tires, and makes the adhesion strength among rubber steel cords of the belt ply become the focus of recently research. This paper focuses on the study of the theoretical analysis of the force on the belt ply, obtaining the relationship between the size of the load at the single steel wire and the outside load and the steel wire’s deformation on a single steel wire. Taking advantage of the software ANSYS Workbench 13.0, we carried out the simulation analysis of the single steel wire, and intuitively showed you the deformation and stress of belt ply’s steel wire under the different forces, providing theoretical basis and reference value for further researches on the adhesion fatigue life of rubber steel wires.
Experimental Study of Vulcanization State on Rubber Mechanical Properties
Authors: Li Tao , Chen Hai Long , Du Dong Xing , Li Qing Ling
Published: February 2012

The mechanical properties and optimum vulcanization times are measured for various rubbers used in the 11.00 R20 S815 all-steel radial tire. Results show the optimum vulcanization time of various rubbers differ a lot from each other, with distinctively different start and ending time of tyre curing process and the duration of the optimum vulcanization stage. The difference, however, are beneficial to the uniformity of the vulcanization degree of tire. The rubbers have best mechanical properties at or near the optimum vulcanization area, while showing weaker properties at under-vulcanization or over-vulcanization stage. The HTME rubber used in tyre tread has minimum abrasion volume under optimum vulcanization stage, while giving increased abrasion volume data under shortened or enlengthened vulcanization time.
Application of Ointment to Foaming SBR
Authors: Zhuang Tao , Zhou Li Ling , An Lu
Published: February 2012

The effects of ointment category, amount of ointment RA-101 and foaming temperature on Vulcanized properties, physical and mechanical properties and the structure of cell of the SBR were investigated. Foaming SBR was made up by machinery and observed by stereoscopic microscope. The results suggested that ointment can make the cell structure distribute more balance and the effects of RA-101 is better than AN; When the amount of RA-101 was 10, the foaming temperature was 175°C, the physical and mechanical properties was better, and cell structure was more balance and surface of rubber was smooth.
Discussion on N-Lamina Model of Non-Plug Flow Solid Conveying in Feeding Section by Single-Screw Extrusion Molding
Authors: Liu Chun Hui , Shi Da Li , Wu Yan Yang , Qin Jian Hua
Published: February 2012

This paper analyzed several important issues in theory of non-plug flow solid conveying, which is about the extrusion molding process of the single screw extruder, they are mainly: compressive stress on the front and rear ends of the surface, and ; an increase trend of compressive stress , ; pressure in feeding compression section of the screw, .
Rheological Characterization and Mathematical Modeling of a SEBS Blend for Industrial Applications where Nowadays Liquid Silicone Rubber is Used
Authors: Juárez D. , Ferrándiz S. , Balart R. , Reig M.J. , Peydró M.A.
Published: February 2012

SEBS (styrene-ethylene/butylene-styrene) is a hydrogenated SBS used as a compatibilizer of other thermoplastic or as a blend to improve the properties (mainly impact). There is very little information about SEBSs research, independent of other materials. This study focuses on a blend from the providers SEBS extreme hardness (50% Shore-A 5 and 50% Shore-A 90) in order to analyze the miscibility of mixed materials from the storage of 2 references only. It has been used the thermoplastic elastomer Megol TA® SEBS, whose characteristics make it special due to the wide range of hardness and transparency, and can be obtained blend for industrial applications where nowadays liquid silicone rubber is used. Next step is rheological characterization of the blend, analyzing the viscosity for subsequent mathematical modeling. Finally, in order to reproduce the rheological behavior of materials during the injection process, Autodesk Moldflow Inside 2010 CAE (Computer Aided Engineering) tool has been used with Cross-WLF model parameters, and compared with tests injected.
Energy Requirements in Manufacturing: Lifecycle and Tribology Considerations
Authors: Schmid S.R.
Published: February 2012

Energy sources, in the form of coal, oil, natural gas, solar or nuclear power, are global commodities, and as demand is projected to rise in the coming decades, so will costs. As such, an understanding of the energy needs of manufacturing processes and the ability to reduce the energy and carbon footprints are essential for sustainability reasons. This paper examines the global sources of energy, since the source used has a large effect on the cost and environmental impact of energy. Energy source effects are quantified in a number of measures. The theoretical approaches used to obtain a carbon footprint are explained and their shortcomining identified. Models of energy needs by manufacturing process are then examined, along with models incorporating the use of ancillary equipment such as pumps, filters, blowers, lighting, etc. Finally, the successful application of tribological principles to influence energy consumption is discussed.
Design of a MEMS Broadband Microstrip Patch Antenna Based on Minkowski Fractal Boundary
Authors: Lu Chong Ying , Xu Li Xin
Published: February 2012

A MEMS broadband microstrip patch antenna based on Minkowski fractal boundary is designed. An air layer is designed in the antenna’s high resistance silicon substrate by MEMS technology and microstrip patch antenna with second degree iteration Minkowski fractal boundary is simulated. Then different p on the influence on the broadband performance of the antenna is discussed. The simulation results show that the broadband performance can be gained from microstrip patch antenna with MEMS air layer based on second iteration Minkowski fractal boundary. 23.34% relative bandwidth of the optimized antenna is achieved and the requirement of the broadband communication is satisfied.
Eliminating the External Libration Sound for the Optical Microsphere-Taper Coupling Structure
Authors: Wang Li , Xu Peng Fei , Zhang Yu Guang , Yan Ying Zhan , Yan Shu Bin
Published: February 2012

This paper describes the effects of the microsphere-taper coupling structure from the external libration Sound, especially the impact on the coupling distance. Here two solutions have been proposed. One approach is to cover the system with a insulation shield. The other is to integrate the coupling structure with the ultraviolet glue. The results show that both measures are viable. The packaged microsphere-taper coupling structure is entirety separated from the nonego, making the structure not be disturbed by the external libration sound. In the subsequent experimentation, the packaged structure will have a good prospect.
Study of a MEMS Short-Circuit Fuse Based on Electro-Thermal Theory
Authors: Zhao Yue , Li Dong Guang , Lou Wen Zhong , Zhang Long Fei , Li Jian Hua , Fang Mao Bo
Published: February 2012

With development of MEMS pyrotechnics devices such as semiconductor bridge/metal bridges, the energy required to fuze ignition becomes smaller and smaller. The energy needed for traditional short-circuit is far greater than MEMS pyrotechnics devices explosive, and takes a large space of fuze, which does not accord with the smaller trend in fuse volume and ignition energy. This paper describes a MEMS short-circuit fuse based on electro-thermal theory, it has similar volume with MEMS pyrotechnics devices, and the energy required is less than the traditional shorts fuse. This short-circuit fuse has well safety features, short action time, small volume, low cost, and it is suitable to be used in fuse or other areas .
An In Situ Measuring Method for Young's Modulus of a MEMS Film Base on Resonance Frequency
Authors: Chen Han , Rong Hua
Published: February 2012

Large-scale measurement of material property is not suit for the MEMS thin-film. Research the in-situ measuring method for material property of the MEMS thin-film is urgently. A center-anchored circular plate is adopted as the test structure here. The resonance frequency of the circular plate is measured to extract the Young’s modulus of a MEMS thin-film. The accuracy of this non-contact in-situ measuring method has been verified by CoventorWare. The inferences of the stress gradient have been analyzed. The advantages of the test structure and the measuring method present here also have been discussed.
Research on the Hydrophobicity of Black Silicon Based on Virtual Process
Authors: Li Xin , Wang Chen , Sun Guang Yi , Zhao Xin , Zhang Hai Xia , Lu Gui Zhang
Published: February 2012

In previous research, in order to simulate the 3D structure of MEMS device, we developed a software named Virtual Process which can help the designer to testify his/her design by comparing the simulation result with real requirements. As Virtual Process could only find out the difference in structure, we put forward a new method, which can compare the functions of the device to verify the simulation result. In this paper, we take hydrophobicity as an example to show the comparison between the results of simulation and experiment. The hydrophobicity is expressed by contact angle, which is measured by certain device in reality. In this case, this paper put forward a method to calculate the contact angle to verify the hydrophobicity of black silicon. Besides, we put forward a method combining micro/nano dual-scale DRIE to realize the simulation of black silicon before the calculation. As a result, the contact angle of black silicon between our calculating method and the actual value is only 7° .
Design, Fabrication and Characterization of a 5x5 Array of Piezoresistive Stress and Temperature Sensors
Authors: Dou Chuan Guo , Wu Yan Hong , Yang Heng , Li Xin Xin
Published: February 2012

This paper reports on the development and characterization of piezoresistive stress and temperature sensors fabricated on silicon-on-insulator (SOI) wafer. The sensor chip consists of a 5x5 array elements enabling the simultaneous measurement of the absolute temperature as well as in-plane stress components in a temperature compensated manner. Each cell comprises a p-type piezoresistor rosette paralleling to the [110] crystal direction of silicon, an n-type piezoresistor rosette along the [100] crystal direction and a temperature sensor. Design, fabrication and characterization of piezoresistive and temperature sensors are described in detail. Moreover, based on the flexible printed circuit board, the prepackaging technique of sensors is reported and the electrical connections between the testing sensors and external measuring devices are achieved, then the changes in resistance versus temperature changes are measured in our experiment, the results show that this approach can be used for the signal measurement of sensor before the second packaging and on-line measurement of packaging stresses.
Low Frequency Electrochemical Accelerometer with Low Noise Based on MEMS
Authors: He Wen Tao , Chen De Yong , Li Guang Bei , Wang Jun Bo
Published: February 2012

Petroleum prospecting and early warning of some geological disaster increasingly depend on the accelerometers which can detect vibrate of frequency below 1Hz, but it’s embarrassing that accelerometers based on Si or SiO2 structure make an awful performance in this frequency range. Electrochemical accelerometers were developed in 1990s. With fluidics to be inertial mass, electrochemical accelerometer not only show an excellent property in low frequency, but also has a wide dynamic range. However, traditional fabrication process of electrochemical accelerometer is rather complex and can’t eliminate the noise due to the inconsistency and asymmetry of electrodes. To solve these problems, a scheme based on MEMS is proposed here, including design, fabrication and package. Properties of electrochemical accelerometer (EAM) are tested in two conditions at last.
Holistic Measurement in the Sheet-Bulk Metal Forming Process with Fringe Projection
Authors: Ohrt Christoph , Hartmann Wito , Weickmann Johannes , Kästner Markus , Weckenmann Albert , Hausotte Tino , Reithmeier Eduard
Published: February 2012

Sheet bulk metal forming is a new forming technology, currently developed by several companies and research institutes. It creates high demands on the inspection of parts and tools, especially in the field of in-situ abrasion detection of the forming tool and its impacts on the work piece. This manuscript introduces two optical testing methods for fulfilling these inspection tasks: On the one hand the endoscopic fringe projection as a flexible small scale optical measurement principal with high depth of focus and accuracy for the acquisition of filigree form elements for a continuous abrasion determination and one the other hand the multi-scaled fringe projection for a holistic one shot measurement of the work piece for an adapted, multiscale deviation analysis. The development and advantages of both systems for the sheet bulk metal forming process are shown as well as potentials of the combination of the both systems close to the proposed application next to the production line.
Comparisons of Numerical Modelling of the Selective Laser Melting
Authors: Van Belle Laurent , Vansteenkiste Guillaume , Boyer Jean Claude
Published: February 2012

Selective laser melting (SLM) first developed for rapid prototyping (RP) is now used for rapid manufacturing of parts with inner complex shapes that cannot be made by more conventional routes. For example, production of injection moulds with cooling channels is of special interest. In this paper, a numerical model of SLM process was investigated to simulate the genesis of residual stresses. The proposed numerical modelling is based upon a double meshing with a multi step birth and death technique of manufactured part. The influence of the mesh size is analysed with element as small as the powder layer thickness for 2D and 3D geometries of simple parts. Comparisons between plane stress, plane strain, and 3D analysis are presented in order to propose a simplified approach.
A Procedure for the Evaluation of Flow Stress of Sheet Metal by Hydraulic Bulge Test Using Elliptical Dies
Authors: Lazarescu Lucian , Nicodim Ioan Pavel , Comsa Dan Sorin , Banabic Dorel
Published: February 2012

The paper describes a new experimental procedure for the determination of the curves relating the equivalent stress and equivalent strain of sheet metals by means of the hydraulic bulge tests through elliptical dies. The procedure is based on an analytical model of the bulging process and involves the measurement of only two parameters (pressure acting on the surface of the specimen and polar deflection).
Measurement and Modelling of Chemical Shrinkage of Thermoset Composites
Authors: Nawab Yasir , Boyard Nicolas , Sobotka Vincent , Casari Pascal , Jacquemin Frederic
Published: February 2012

Knowledge of resin chemical shrinkage is crucial for the determination of residual strains, stresses and warpage of composite parts during curing. Shrinkage measurement is more accurate on several millimetre thick samples. However, in that case thermal properties of resin and the strong coupling between thermoset chemical reactions (generally rapid and strongly exothermal) and thermal fields lead to non-negligible thermal and curing gradients in the piece. It is then necessary to take these variations into account to have an accurate description of the shrinkage. In the present study, a home built device "PVT-α" mould is used to measure the volume variation of vinylester resin and associated composites during the curing and then shrinkage is identified by considering these gradients. The results demonstrate that a linear evolution of the shrinkage with conversion degree is a good model to describe the chemical effect on the global volume behavior of the piece. The contribution of chemical and thermal effects on volume curve is quantified.
Single Roll Caster Equipped with a Scraper
Authors: Haga Toshio , Akitsu Kazuya , Kamakura Keisuke , Kumai Shinji , Watari Hisaki
Published: February 2012

A scraper was developed and attached to the single roll caster in order to improve the free solidified surface of as-cast strip cast. Semisolid metal on the free solidified surface was flattened by the scraper and the surface became flat. The AA5182 aluminum alloy could be cast at speeds up to 40m/min. Thickness was about 3mm. Pressure of the unit width of the scraper was ranging from 0.1N/mm to 1.0N/mm, and these pressure was enough to make the free solidified surface flat. Center line segregation did not occur as the strip was solidified from single side at the strip cast by the single roll caster. Roll-cast strip could be cold rolled down to 1mm. There was not difference between the roll contact surface and the free solidified surface of the strip after cold rolling judging by a visual examination. Result of tension test of the roll cast and cold rolled strip was as same as that of D.C. cast and rolled strip. Deep drawing test was operated at the conditions both of the roll contact surface and the free solidified surface were outer side. LDR (limited drawing ratio) was same at both conditions and they were 1.8. Thickness of the strip was controlled by the roll speed, solidification length (length of the melt pool) and pressure of the scraper. The single roll caster is simpler than a twin roll caster. Rigidity for rolling was not required for the single roll caster. Cost of the roll is half comparing a twin roll caster. The equipment cost of the single roll caster is more economy than that of the twin roll caster.
Experimental and Numerical Determination of Cutting Forces and Temperatures in Gear Hobbing
Authors: Stark Sibylle , Beutner Martin , Lorenz Falk , Lampke Thomas , Karpuschewski Bernhard , Halle Thorsten
Published: February 2012

Hobbing is one of the most productive methods for manufacturing external gears. According to the requirements of green manufacturing, the lubrication in gear hobbing has to be reduced with the final aim of dry machining. Influences due to thermal aspects during machining have to be considered, especially in hobbing of large modules or ring gears, because in this case, hobbing could be the last step in the process chain. Within the priority program (SPP) “Modeling, Simulation and Compensation of Thermal Effects for Complex Machining Processes”, founded by the DFG, special emphasis is laid on the thermally caused geometrical deviation in dry cutting. To predict the heat flux, which leads to thermal expansions and geometrical deviations of the gear, a validated model for forces and temperatures is necessary. The validation of single generation positions and chips is focused in this paper.
3D Interlock Composite Preforming Simulation
Authors: Orliac Jean Guillaume , Charmetant Adrien , Morestin Fabrice , Boisse Philippe , Otin Stephane
Published: February 2012

In order to simulate 3D interlock composite reinforcement behavior in forming processes like Resin Transfer Molding (RTM), it is necessary to predict yarns positions in the fabric during the preforming stage of the process. The present paper deals about thick 3D interlock fabric forming simulation using a specific hexahedral semi-discrete finite elements simulation tool : Plast4. Using the virtual work principle, we distinguish the virtual internal work due to tensions in yarns from other internal virtual works. The part of material stiffness relative to yarns tension is described as "first order stiffness" by a 3D discrete beam model. The rest of the rigidities - like transverse compression, shear strains or friction between yarns - are depicted by a continuous quad-based discretization designated in our work as "second order stiffness". A combination of this "first order" discrete model and a continuous orthotropic hyperelastic "second order" material formulation will enables us to simulate interlock preforming process. Jointly to the simulation work, we also had to specify and perform experimental testing identification of material's parameters. Thoses parameters concern both parts of the model. A bilinear tension approach for the yarns discrete modelization and an orthotropic continuous material for the "second order" part.
Thixo Lateral Forging of a Commercial Automotive Spindle from LTT45 Steel Grade
Authors: Lozares Jokin , Azpilgain Zigor , Hurtado Iñaki , Ortubay Rafael , Berrocal Susana
Published: February 2012

The present paper is focused on the thixo lateral forging of a nearly 3 Kg commercial automotive spindle. A thixoforming cell has been implemented in the forming lab consisting on an induction unit, six-axes industrial robot for the handling tasks and a servo-mechanical forming press. A special tool has also been designed in order to use all the press capacity during the forming stage. First trials have been made using LTT45 steel. The usual material for this spindle fabrication is a CrMo alloyed steel (W-Nr 1.7225) employed in automotive components with high requirements on toughness. The selected thixoforming steel has been modified to have a wider solidification range and lower solidus temperature.
Manufacturing of Steel-Reinforced Aluminum Products by Combining Hot Extrusion and Closed-Die Forging
Authors: Foydl Annika , Pfeiffer Insa , Kammler Matthias , Pietzka Daniel , Matthias Thorsten , Jäger Andreas , Tekkaya A. Erman , Behrens Bernd-Arno
Published: February 2012

Aluminum matrix composite extrusions reinforced with wires made of high strength stainless steel represent an innovative material concept for lightweight structures. The use of reinforcing elements should improve the mechanical properties and the performance of lightweight structures. This study deals with the process chain of extrusion and die forging to manufacture steel-reinforced products. The production of discontinuously-reinforced, semi-finished aluminum profiles by co-extrusion is in focus on the extrusion part. The material flow is analysed in order to understand, and further to influence, where the steel-reinforcements are appear in the strand. For the forging part the extruded profiles are continuous-reinforced by means of steel wires as well as partially by means of steels elements. For the process design the geometry of the forging die cavity and the material flow are of vital importance. A Finite Element Analysis is carried out in order to predict the position of the elements in the forging parts depending on the position in the extrusions.
The Model for Coupled Simulation of Thin Profile Extrusion
Authors: Biba Nikolay , Stebunov Sergei , Lishny Andrey
Published: February 2012

The paper presents the latest development of the numerical model for extrusion of industrial profiles having complex shapes. The model provides the material flow analysis coupled with mechanical and thermal problems in the tooling set. The simulation predicts possible shape deterioration due to uneven material flow through the bearing zone and helps to equalise it by means of optimisation of the bearing design, chamber and feeding channels. The locations of welding zones in the die are clearly predicted. It allows to modify the die design for better welding conditions and to provide optimal location of welding seams in the product. Die stress analysis shows the ways to extend the tool life by means of reducing of fatigue failure and selecting proper die materials as well as to correct the influence of the die deformation on the material flow. The described model is implemented in an especially dedicated program QForm-Extrusion that effectively simulates the extrusion of hollow and solid profiles with very high elongation ratios. The experimental verification of the model is illustrated by model and industrial experiments as well as by series of case studies performed in production environment.
Experimental Study of a Full Forward Extrusion Process from Metal Strip
Authors: Merklein Marion , Stellin Tommaso , Engel Ulf
Published: February 2012

A high rate of production of complex microparts is increasingly required by fields like electronics and micromechanics. Handling is one of the main problems, limiting those forming processes of small metal components consisting of multiple forming stages. A forming chain in which a metal strip acts both as raw material and support of the workpiece through the different stages of the process, is seen as a solution that radically simplifies the positioning of microparts. Each workpiece stays connected to the strip through all the forming steps, being separated just at the end of the process chain. In this work, a tooling system for the bulk forming from copper strips has been set up and employed in a full forward extrusion process of a micro-billet. The same die, with a diameter of 1 mm, has been used with three different strip thicknesses (1, 2 and 3 mm) and three different material conditions. The use of thinner and hard-as-rolled strips has resulted in achieving a higher ratio of the billet length to strip thickness.
AZ31 Magnesium Alloy Parameters Identification through Inverse Analysis at 713 K
Authors: Giuliano Gillo
Published: February 2012

This paper introduces a fast and accurate procedure for determining the constants of magnesium AZ31 alloy at 713 K. The material behaviour is modelled by means of the power law relationship between the equivalent flow stress, the equivalent strain and the equivalent strain-rate within a narrow equivalent strain-rate range. Bulging tests were carried out in isothermal conditions (713 K) and at constant pressure in order to determine the material constants. It is necessary to evaluate the displacement and the thickness evolutions at the dome apex of the metal sheet. The time-displacement curve was obtained by laser measurements whereas a large number of bulging tests, interrupted at preset time intervals, were carried out to evaluate the thickness. The thickness was measured directly using a two-digit micrometer. The material constants, m, n and K were obtained in the power law relationship by means of constant pressure bulging tests coupled with the use of an inverse analysis technique. The results of comparison between experimental and numerical tests are shown and they indicate that the material constants can be accurately evaluated.
Superplastic Forming/Diffusion Bonding of a Titanium Alloy for the Realization of an Aircraft Structural Component in Multi-Sheets Configuration
Authors: Carrino Luigi , Paradiso Valentino , Franchitti Stefania , Squillace Antonino , Russo Salvatore
Published: February 2012

Superplastic forming and diffusion bonding (SPF/DB) is a near-net-shape forming and joining process used with alloys having superplastic properties in order to make manufact which should have light weight and high stiffness. The aerospace is one of those sectors in which such technology is mainly used. This process allows to reduce the buy-to-fly ratio and consequently the production costs thanks to the possibility to produce complex shape components in a single shot. The material widely used for this application is the Ti-6Al-4V alloy for its high strength vs weight ratio, excellent mechanical proprieties, corrosion resistance and galvanic compatibility with carbon fiber reinforced composite materials. In this study, finite element analysis of the SPF/DB process has been carried out in order to investigate the thickness prediction, the optimization of the tooling’s geometry and the definition of the sheets initial thickness in the blow forming process of a multi-sheets configuration.