bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of CVS Tunnel, Ambient and Instrument Dilution on Characteristics of Nano Diesel Particulate Matter Evolution
Authors: Wu Yuebin , Clark Nigel N. , Carder Daniel K.
Published: July 2013

In 2007, U.S. certification standards for heavy duty on-road diesel engine particulate matter (PM) emissions were reduced from 0.1g/bhp-hr to 0.01g/bhp-hr, representing an order of magnitude reduction in pollutant level. The Tier 4 standards for nonroad diesel engines, being phased in from 2008 through 2015, also require similar level of reduction in PM. Most conventional diesel engines could meet these low PM standards, once equipped with a diesel particulate filter (DPF). However, accurate, repeatable measurements of this PM may pose significant challenges. Gravimetric PM measurement involves diluting exhaust, then collecting the resultant aerosol sample on approved filter media. Few data exist to characterize the evolution of particulate matter (PM) in dilution tunnels, particularly at very low PM mass levels. Data are lacking as well, for PM evolution in portable dilution instruments and in exhaust plumes downstream of the tailpipe. Size distributions of ultra-fine particles in the diesel exhaust from a naturally aspirated ISUZU C240 diesel engine, equipped with a DPF, were studied. Particle size distribution data, during steady-state engine operations, were collected using a Cambustion DMS500 Fast Particulate Spectrometer. The effects of dilution ratios, dilution rates, and residence times on the diesel particulate matter (DPM) size distributions were analyzed and discussed. Measurements were made for three dilution methods: dilution in standard primary and secondary-dilution tunnels with a full scale Constant Volume Sampler (CVS) system, instrument dilution with a Portable Particulate Measurement Device (PPMD), and ambient dilution at the post-tailpipe exhaust plume centerline. Gaseous emissions measurements were utilized as surrogate confirmation of adequate mixing at the various measurement locations, as well as an indicator of dilution ratios. Tunnel sample results indicated varying size distributions at tunnel cross sections where the flow was still developing. Evolution of particle-size distributions was observed even for fully mixed primary flow conditions. Size distributions at the end of the secondary dilution tunnel were observed to vary with different secondary-dilution ratios. Particle-size distributions of post-tailpipe and PPMD test results were analyzed and compared with those results collected from the full-flow tunnel. Results from post-tailpipe sampling indicate that nucleation was the dominant process when the exhaust plume was diluted along the post-tailpipe centerline. Results from PPMD dilution measurements indicate that change of particle-size-distribution curves, including number count and mass concentration levels, were not as strongly correlated to dilution ratios as were the results from the other two sampling methods. This study shows that particle-size distributions measured inside full-flow dilution tunnel can adequately mimic freshly emitted exhaust sampled immediately post-tailpipe.
Investigation of Injection Strategies to Improve High Efficiency RCCI Combustion With Diesel and Gasoline Direct Injection
Authors: Wissink Martin L. , Lim Jae H. , Splitter Derek A. , Hanson Reed M. , Reitz Rolf D.
Published: July 2013

Experiments were performed to investigate injection strategies for improving engine-out emissions of RCCI combustion in a heavy-duty diesel engine. Previous studies of RCCI combustion using port-injected low-reactivity fuel (e.g., gasoline or iso-octane) and direct-injected high-reactivity fuel (e.g., diesel or n-heptane) have reported greater than 56% gross indicated thermal efficiency while meeting the EPA 2010 heavy-duty PM and NOx emissions regulations in-cylinder. However, CO and UHC emissions were higher than in diesel combustion. This increase is thought to be caused by crevice flows of trapped low-reactivity fuel and lower cylinder wall temperatures. In the present study, both the low- and high-reactivity fuels were direct-injected, enabling more precise targeting of the low-reactivity fuel as well as independent stratification of equivalence ratio and reactivity. Experiments with direct-injection of both gasoline and diesel were conducted at 9 bar IMEP and compared to results from experiments with port-injected gasoline and direct-injected diesel at matched conditions. The results indicate that reductions in UHC, CO, and PM are possible with direct-injected gasoline, while maintaining similar gross indicated efficiency as well as NOx emissions well below the EPA 2010 heavy-duty limit. Additionally, experimental results were simulated using multi-dimensional modeling in the KIVA-3V code coupled to a Discrete Multi-Component fuel vaporization model. The simulations suggest that further UHC reductions can be made by using wider injector angles which direct the gasoline spray away from the crevices.
Meniscus Formation in the Piston Compression Ring-Cylinder Liner Inlet Zone
Authors: Rahmani Ramin , Styles Gema , Rahnejat Homer
Published: July 2013

The piston compression ring-cylinder liner contact experiences a transient regime of lubrication. This comprises hydrodynamic, mixed (partial) or boundary interactions. The regime of lubrication is influenced by contact kinematics, loading, mechanical and topographical properties of the bounding solid surfaces, as well as lubricant rheology and its supply to feed the conjunction. Ideally, a sufficient volume of lubricant would exist at the conjunctional inlet, which acts as a meniscus, from which a film of lubricant is entrained into the contact area. However, often there is an insufficient volume at the inlet to the contact or unfavourable kinematic conditions exist, such as at the dead centre reversals in the piston system. Such conditions are generally regarded as the underlying reasons for mixed or boundary regimes of lubrication. Whilst, these are the main reasons for failure to form a coherent lubricant film at dead centre reversals, poor hydrodynamic lubrication can also occur elsewhere in the piston cycle due to the lack of an inlet meniscus. This may be as the result of poor ring-bore conformability, where a meniscus cannot be formed in an increasing clearance space. Numerical analyses reported in open literature often assume an idealised fully flooded or drowned inlet. Other analyses assume starved inlet boundaries, usually based on a lubricant availability model, which itself is based on an assumed supply of lubricant on free surfaces ahead of the contact. It is, however, important to establish the limiting clearance space which would allow the lubricant to adhere to the adjacent boundary solids and, thus form a meniscus bridge. The current study is aimed at establishing inlet meniscus conditions. This would depend on the lubricant surface tension, affected by the free surface energy of liquid-vapour interface and the contact angle made between the lubricant and the bounding solids. It also depends on the solid surfaces, any coatings and their topography.

In general, the results indicate the dependence of the meniscus force on surface material and topography, through measurement of contact angles made by the various compression rings against the various cylinder liner surfaces, using an especially developed rig and in conjunction with a goniometer. Obviously, the measurements do not exactly replicate those existing in a fired engine. Nonetheless, this initial study provides a good insight into oil-surface combination in separating gaps, which is far more representative than the usually assumed idealised inlet conditions.
Influence of Coconut Biodiesel and Waste Cooking Oil Blended Fuels on Engine Performance and Emission Characteristics
Authors: Liaquat A. M. , Masjuki H. H. , Kalam M. A. , Bhuiya M. M. K. , Varman M.
Published: July 2013

Due to diminishing petroleum reserves and the environmental consequences of exhaust gases from petroleum fuelled engines, alternative fuels are becoming increasingly important for diesel engines. The processed form of vegetable oil (Biodiesel) and waste products (waste cooking oil) offer attractive alternative fuels for compression ignition engines. In this study experimental work has been carried out to investigate engine performance parameters and emissions characteristics for direct injection diesel engine using coconut biodiesel and waste cooking oil blends without any engine modifications. A total of three fuel samples, such as DF (100% low-sulfur diesel fuel), CB10 (10% coconut biodiesel and 90% DF), and C5W5 (5% CB + 5% waste cooking oil and 90% DF) respectively are used. Engine performance test was performed at 100% load keeping throttle 100% wide open with variable speeds of 1500 to 2400 rpm at an interval of 100 rpm. Whereas, emission tests were carried out at 2300 rpm at 100% and 80% throttle position. As the results of investigations, there has been a decrease in torque and brake power, where increase in specific fuel consumption has been observed for blend fuels over the entire speed range as compared to diesel fuel. In case of engine exhaust gas emissions, lower HC, CO, CO2 emissions and higher NOx emissions, were found for fuel blends compared to diesel fuel. However, sound level for both blend fuels was lower as compared to diesel fuel. It can be concluded that CB10 and C5W5 can be used in diesel engines without any engine modifications and have beneficial effects both in terms of emission reductions and alternative petroleum diesel fuel. However, C5W5 produced better results compared to CB10.
Particulate Matter Emission Characterization From a Natural Gas Fuelled High Pressure Direct Injection Engine
Authors: Patychuk Bronson , Rogak Steven N.
Published: July 2013

High-Pressure Direct-Injection (HPDI) combustion of Natural Gas can reduce the gaseous and Particulate Matter (PM) emissions compared to a conventional diesel engine. Upcoming EPA and EURO emission limits may restrict particle number as well as particle mass. In preparation for these upcoming limits, the PM mass, size and composition was studied from a heavy-duty Cummins ISX engine converted to HPDI operation. To characterize the PM emissions, tests were based around a mid-speed, high-load operating point. Injection timing, equivalence ratio, gas supply pressure, EGR % and diesel injection mass were isolated and varied. PM emissions were characterized by the mobility size distribution, light scattering and filter loading. In addition a novel thermodenuder was used to determine the PM volatile fraction. It was found that EQR and EGR have the greatest effect on PM mass emissions and the correlations between these parameters are evaluated. The mean particles size and number concentrations are again most effected by EGR and EQR with smaller effects from the GRP and diesel pilot. The size distributions of the parameter variations are similar and there are no nucleation mode ultrafine particles observed. The volatile fraction is fairly constant across the parameter variations and is found to be around 18% of the mass and 11% by number of particles at this high load condition.
Application of Continuous Thermodynamics Method to Fuel Droplet Evaporation
Authors: Cheng Way Lee , Shen Cai , Lee Chia-fon F.
Published: July 2013

A finite diffusion droplet evaporation model for complex liquid mixture composed of different homogeneous groups is presented in this paper. Separate distribution functions are used to describe the composition of each homogeneous group in the mixture. Only a few parameters are required to describe the mixture. Quasi-steady assumption is applied in the determination of evaporation rates and heat flux to the droplet, and the effects of surface regression, finite diffusion and preferential vaporization of the mixture are included in the liquid phase equations using an effective properties approach. A novel approach was used to reduce the transport equations for the liquid phase to a set of ordinary differential equations. The proposed model is capable in capturing the vaporization characteristics of complex liquid mixtures.
Some Aspects of Micro-Fabrication Using Electro Discharge Deposition Process
Authors: Jain V. K. , Seshank S. , Sidpara Ajay , Jain Himanshu
Published: July 2013

The growing demand for micro-parts has led to the development of many processes for their production. One of the emerging processes in this category is the electric discharge deposition process in which a micro tool in the form of a wire is used. The tool wear is increased intentionally so that the worn out material gets deposited on the substrate. Experiments are designed using response surface methodology to identify the key operating parameters (voltage, current, duty cycle and pulse on-time) and then to study their effects on the structure’s height, and width. As a concluding part, micro parts (star and letters IITK) are fabricated on the substrate material and a method is proposed and demonstrated to detach micro parts from the metallic substrate material.
Two-Dimensional Real-Time Interferometric Monitoring System for Exposure Controlled Projection Lithography
Authors: Jariwala Amit S. , Schwerzel Robert E. , Werve Michael , Rosen David W.
Published: July 2013

Stereolithography is an additive manufacturing process in which liquid photopolymer resin is cross-linked and converted to solid polymer with an ultraviolet light source. Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in which incident radiation, patterned by a dynamic mask, passes through a transparent substrate to cure a photopolymer layer that grows progressively from the substrate surface. In contrast to existing stereolithography techniques, this technique uses a gray-scale projected image, or alternatively a series of binary bit-map images, to produce a three-dimensional polymer object with the desired shape, and it can be used on either flat or curved substrates.

Like most stereolithographic technologies, ECPL works in a unidirectional fashion. Calibration constants derived experimentally are fed to the software used to control the system. This unidirectional fabrication method does not, by itself, allow the system to compensate for minor variations, thereby limiting the overall accuracy of the process. We present here a simple, real-time monitoring system based on interferometry, which can be used to provide feedback control to the ECPL process, thus making it more robust and increasing system accuracy. The results obtained from this monitoring system provide a means to better visualize and understand the various phenomena occurring during the photopolymerization of transparent photopolymers.
One Fast Fixture Layout and Clamping Force Optimization Method Based on Finite Element Method
Authors: Liu Zhihui , Wang Michael Yu , Wang Kedian , Mei Xuesong , Hua Guo
Published: July 2013

Aimed to reduce the deformation of workpiece-fixture system, one fixture layout and clamping force optimal method is constructed in this paper. Firstly, system stiffness matrix is built by Finite Element Method (FEM), and one matrix size reducing method is proposed to avoid the high computing time cost of solving FEM balance equation. Secondly, one clamping force optimization method which should be called after fixture layout is generated during every step of optimization algorithm is presented to lessen calling times of FEM solving process and save running time. And then based on these, one fixture layout and clamping force optimization algorithm is constructed using genetic algorithm (GA). At the end of this paper, numeral examples are taken to verify the validity and usability of the methods.
Fabrication of Microfluidic Chips by an Ultrasonic Micromachining With Wet-Etch Smoothing Method on Glass Substrates
Authors: Liu Keyin , Zhao Yulong , Yang Qing , Li Lei , Fan Xiaole , Peng Niancai
Published: July 2013

An ultrasonic micromachining with wet-etch smoothing process is demonstrated in this work to fabricate microfluidic chips on glass substrates. Microstructures of high aspect ratios including microchannels, microchambers and microholes were fabricated in glass substrates within a few minutes. A thin sellotape film and a sacrificing glass sheet were attached on the sample surfaces, preventing the surface scratches and cracks at the exits of the through holes. The surface morphology of the microstructures was improved by a smoothing process of ultrasonic-assisted chemical etching using the hydrofluoric (HF) acid solutions. Using this method, microfluidic chips for capillary electrophoresis (CE) and solo-chamber chips were fabricated.
Cyberinfrastructure Enabling Personalized Production
Authors: Viswanathan J. , Tilbury D. M. , Hu S. J. , Mao Z.
Published: July 2013

The Internet has facilitated the development of e-businesses using web-based services leveraging back-end database systems, inventory systems and payment processing systems. Online retail businesses can be set up in a relatively short period of time. In contrast, set-up of a manufacturing system takes much longer; the system design involves various stages from gaining an understanding of the product and its market to machine selection, layout, control logic, part flow analysis and so on. Cyberinfrastructure has the potential to revolutionize the design and operation of manufacturing systems by creating a collaborative environment distributed across a number of physical locations through web-based virtual communities, thereby simplifying and streamlining the manufacturing system design and integration. This paper describes how current technologies could facilitate the implementation of a cyberinfrastructure for manufacturing. A case study describing a current manufacturing system architecture and how a future one would use cyberinfrastructure is used to describe major gaps that exist and standards that need to be developed.
Hierarchical-Game Based Negotiation for Supply Chain Network
Authors: Yu Fang , Kaihara Toshiya , Fujii Nobutada
Published: July 2013

This paper focuses on the single-attribute negotiation between multi-MA (Manufacture Agent) and multi-MSA (Material Supplier Agent). A hierarchical-game based negotiation protocol is proposed. It is a three-layer game. Nash game is used to find the optimal trade partnership to maximize the whole profits of the SCN (Supplier Chain Network) in the first layer. The second layer games are aimed to find all possible coalitions if the order is out of the ability of MSA and determine the final coalitions of each MSA for each MA using cooperative games. The third layer games are used to determine the final strategies between MAs and MSAs or all possible coalitions found in the second layer games. Stackelberg equilibrium is introduced to resolve the conflict of interests of the two sides. The first layer game is based on the results of the second and third layer games. The second and third layer games are nested inside the first layer game. Simulations and analysis are provided to verify the effectiveness and feasibility of the proposed protocol.
A Comparison of Two Methods for Geometric Milling Simulation Accelerated by GPU
Authors: Inui Masatomo , Umezu Nobuyuki , Shinozuka Yuuki
Published: July 2013

For detecting potential problems of a cutter path, cutting force simulation in the NC milling process is necessary prior to actual machining. A milling operation is geometrically equivalent to a Boolean subtraction of the swept volume of a cutter moving along a path from a solid model representing the stock shape. In order to precisely estimate the cutting force, the subtraction operation must be executed for every small motion of the cutter. The performance and the cost of the polygon rendering LSI called GPU are dramatically improved these days. By using GPU, the required time for critical computations in the geometric milling simulation can be drastically reduced. In this paper, the computation speed of two known GPU accelerated milling simulation methods, which are the depth buffer based method and the parallel processing based method with CUDA language, are compared. Computational experiments with complex milling simulations show that the implementation with CUDA is several times faster than the depth buffer based method when the cutter motion in the simulation process is sufficiently small.
USARSim/ROS: A Combined Framework for Robotic Control and Simulation
Authors: Balakirsky Stephen , Kootbally Zeid
Published: July 2013

The Robot Operating System (ROS) is steadily gaining popularity among robotics researchers as an open source framework for robot control. Additionally, the Unified System for Automation and Robot Simulation (USARSim) has already been used for many years by robotics researchers and developers as a validated framework for simulation. This paper presents a new ROS node that is designed to seamlessly interface between ROS and USARSim. It provides for automatic configuration of ROS transforms and topics to allow for full utilization of the simulated hardware. The design of the new node, as well as examples of its use for mobile robot and robotic arm control are presented.
Life Cycle Assessment of Complex Heavy Duty Equipment
Authors: Kwak Minjung , Kim Louis , Sarvana Obaid , Kim Harrison M. , Finamore Peter , Hazewinkel Herb
Published: July 2013

This paper presents a comprehensive life cycle assessment (LCA) study of heavy duty off-road equipment. The machine studied here is a typical piece of diesel construction machinery equipped with the iT4 (interim Tier 4) certified diesel engine. Two life cycle impact assessment methods, Eco-Indicator 99 and IPCC 2007, are used to calculate the environmental impact and global warming potential associated with the machine’s life cycle, from material extraction to end-of-life recycling and disposal. Due to fuel consumption and emissions, machine utilization during the usage phase is expected to account for most of the total environmental impact. However, the impact from usage can vary greatly, depending on how customers use the machine. To take into account various machine usage patterns, this LCA study performs two sensitivity analyses, varying the load factor and varying the fuel consumption rate, respectively.
Direct Selective Laser Sintering of WC-Co Cemented Carbide by Premixing of Additives
Authors: Kyogoku Hideki , Uemori Takeshi , Ikuta Akihiko , Yoshikawa Kenichi , Ohmori Hitoshi
Published: July 2013

In this study, the fabrication conditions of WC cemented carbides by direct selective laser melting were investigated. The effects of additives, such as Co, Cu-20%Sn and Cu powders, and laser scanning conditions on laser sintering process were examined to fabricate a sound laser-scanned body of WC cemented carbides. The optimum laser power, scan speed and scan pitch were found out by experiments. It was found that the continuously smooth single-scan track can be obtained at a lower laser power and a higher scan speed by the addition of 30% Cu powder. The smooth surface of the laser-scanned body could be fabricated at a laser power of 9 W, a scan speed of 20 mm/s and a scan pitch of 0.05 mm.
A Human Oriented Real-Time Scheduling for Autonomous Distributed Manufacturing System: Control of Preferences of Human Operators Aimed at Improving Productivity
Authors: Iwamura Koji , Hayashi Hitoshi , Tanimizu Yoshitaka , Sugimura Nobuhiro
Published: July 2013

A real-time scheduling method considering human operators has been proposed to generate suitable production schedules for human operators, manufacturing equipment and jobs real-timely in the autonomous distributed manufacturing systems (ADMSs). The proposed scheduling method gives the higher priorities to the human operators, and generates the production schedules based on preference values, in order to improve the human operator’s motivation. It was shown, through case studies, that the proposed real-time scheduling method is effective to satisfy the preferences of the human operators. However, the make span is deteriorated especially for the cases where the human operators have similar preferences. Therefore, a new method is proposed to calculate the preference values considering not only the preferences of human operators but also improvement of productivity.
Customization of a Micro Process Planning System for an Actual Machine Tool Based on Updating a Machining Database and Generating a Database Oriented Planning Algorithm
Authors: Igari Shinji , Tanaka Fumiki , Onosato Masahiko
Published: July 2013

To generate optimal machining information, an automatically customizable micro process planning system that reflects the change of properties of an actual machine tool is proposed. The system consists of an updatable machining database and a database oriented micro process planning algorithm. A machining database is updated based on analyzing NC data that are adaptively generated for an actual machine tool by skilled process planners. From the updated machining database, a database oriented micro process planning algorithm is generated by a decision tree and a regression tree. Machining strategy and cutting tools are determined using IF-THEN rules that are generated from the database by decision tree method. Cutting conditions were determined from a feasible regression equation. Regression equations and selection rules of these equations were generated from the database by regression tree method. The example of micro process planning using the generated algorithm is also shown.
The Annealing Effect of the High-Pressure Phases of Silicon During Micro-Laser Assisted Machining
Authors: Ravindra Deepak , Ghantasala Muralidhar K. , Patten John
Published: July 2013

Micro-laser assisted machining (μ-LAM) is a novel micro/nano machining technique developed for ductile mode machining of ceramics and semiconductors. Ductile mode material removal is possible in a nominally brittle material due to the high-pressure phase transformation (HPPT) phenomenon during the machining process. The μ-LAM system utilizes an IR laser beam to preferentially heat and soften the workpiece material during the material removal process. The μ-LAM process has several direct benefits observed during the machining process: allows for deeper cuts in the ductile regime due to the enhanced ductility of the workpiece material, higher material removal rates as a result of deeper cuts, lower cutting forces due to the reduced workpiece hardness from the heating process, and less tool wear from the reduced hardness and lower cutting forces. The μ-LAM process also has an added benefit that eliminates any subsurface damage in the form of high-pressure phases (HPPs) that usually remain after the ductile mode material removal process. This paper discusses this added benefit that occurs due to an annealing effect that re-crystallizes the HPPs back to its original crystalline phase. Single point scratch tests are used to form the HPPs by performing ductile mode μ-LAM on single crystal silicon (Si). Micro-Raman (μ-Raman) spectroscopy is used to characterize the machined surface/subsurface and identify the HPPs and annealed phase.
A Simple Inverter-Motor System to Improve Energy Consumption and Maximum Torque
Authors: Watanabe Tohru , Fujita Yukishige , Totani Mikio
Published: July 2013

A new inverter-AC motor system having four power source lines, which can control each coil current independently, is compared to an ordinary inverter-AC motor system using a Y-type coil connection and three power lines. In this paper, three-phase rectangular-type currents are generated by the inverter made of simple ICs.

In a previous paper[1], similar comparison experiments were executed using a high-speed DSP board. The board can calculate the three-phase currents to generate a rotating, resultant, magnetic flux with a precise constant strength and phase. It was verified by experiments that an energy consumption of 15% can be saved by using the proposed independent, motor-coil currents. However, it requires high speed and high cost DSP or CPU.

In this paper, it is verified by using a new inverter-AC motor system that an energy consumption of 15% can be saved, and also the maximum torque increases 10%.
Non-Contact R-Test for Error Calibration of Five-Axis Machine Tools
Authors: Ibaraki Soichi , Hong Cefu
Published: July 2013

The R-test is a new instrument to measure three-dimensional displacement of a precision sphere attached to a spindle relative to a work table by using three displacement sensors. Its application to error calibration for five-axis machine tools has been studied in both academia and industry. For the simplicity in calculating the sphere center displacement, all conventional R-test devices use contact-type displacement sensors with a flat-ended probe. Conventional contact-type R-test may be potentially subject to the influence of the friction or the dynamics of supporting spring in displacement sensors particularly in dynamic measurement. This paper proposes a non-contact R-test with laser displacement sensors. A new algorithm was proposed to estimate the three-dimensional displacement of sphere center by using laser displacement sensors, It compensates the measurement uncertainty caused by the inclination of the target surface. Experimental case studies are presented to evaluate its measurement performance by comparing with the conventional contact-type R-test device.
Job-Shop Scheduling Approach to Order-Picking Problem
Authors: Iwasaki Yukiyasu , Suzuki Ikuo , Yamamoto Masahito , Furukawa Masashi
Published: July 2013

In recent years, a large-scale logistic center plays an important role in mail-order business with Internet. In the logistic center, the efficient managing is required to deliver products to customers as soon as possible. Researches to efficiently control the logistic center have been done in the various approaches. This study proposed a new method for the order-picking problem considering worker’s jamming at the same shelf in the logistic center. In the proposed method, we formulate worker’s scheduling in the logistic center as Job-shop Scheduling Problem and optimize this problem. Numerical experiments show the proposed method improve worker’s scheduling compared with rule-based scheduling.
An Installation Position and a Shape of an Artificial Hip Joint Suitable for Japanese Daily Activities
Authors: Narita Hirohisa , Yagihashi Makoto , Fujimoto Hideo
Published: July 2013

Regarding Japanese daily activities, there are a lot of situations of dislocation for persons after total hip arthroplasty. The objective of this research is to obtain an installation position and a shape of an artificial hip joint which reduce the risk of the dislocation even if the people do Japanese daily activities. Two magnetic positional sensors attached to body surface are used to measure motions of a hip joint between Westerner dairy and Japanese activities. As a result, adequate conditions of the artificial hip joint suitable for Japanese daily activities can be obtained.
A Method for Efficient Flexible Process Planning by Mathematical Optimization
Authors: Morinaga Eiji , Hara Takuma , Wakamatsu Hidefumi , Arai Eiji
Published: July 2013

Computer support technology for modern manufacturing should deal with variable situations to accomodate to high-mix low-volume manufacturing. Computer-aided process planning (CAPP) has been discussed from this point of view, and a method for flexible CAPP, which generates a new proper process plan easily when manufacturing situation has changed, was proposed for rough milling by a three-axis vertical machine. This method was enhanced to handle millings by a multiaxis vertical machine and by both vertical and horizontal machines. The basic idea of these methods is to generate all process plans and then choose the best one. In the choice process of the best plan, all of the generated plans are evaluated. However, this process requires a large computational power when employed in actual machining where products of complex shapes have to be produced. For this computational problem, this paper discusses application of the mathematical optimization framework to this choice process.
Simulation and Testing of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated by Selective Laser Sintering
Authors: Wu M. , Leu M. C. , Guo N.
Published: July 2013

Polymer Electrolyte Membrane (PEM) fuel cell converts directly electrochemical energy into electricity. Flow channels in bipolar plates, a critical component of fuel cell, were designed, simulated and tested. The bipolar plate used a mixture of graphite materials, and was fabricated using a Selective Laser Sintering (SLS) process. The fabricated green parts were carbonized at high temperatures and converted into brown parts. Infiltration of resin was used to enhance the electric conductivity and strength of the bipolar plate. Finite element simulations were performed to investigate the state of species (hydrogen, oxygen) in the channels and Gas Diffusion Layers (GDLs) for four flow field designs including parallel, serpentine, single Hilbert and composite Hilbert. The simulation results were used to obtain the polarization curves and the relationships between stack power and current density, and to discuss the effect of temperature on fuel cell performance. Experiments were conducted to validate the simulation results on voltage and power vs. current density and the effect of temperature on fuel cell performance for the different flow field designs.
Titanium Scaffolds for Custom CMF Restorations
Authors: Dybala Bogdan , Chlebus Edward
Published: July 2013

Patients after trauma or tumor removal often require restoration of cranio-maxillo-facial bone functions and aesthetics. Additive manufacturing technologies offer an efficient solution in production of custom-designed implants for specific clinical cases. Their capabilities also allow for manufacturing objects with complex geometries, including tissue engineering scaffolds – implants with internal structure. The paper presents first achievements of a project aimed at design and manufacture of individualized functionalized bone scaffolds for CMF oncological patients. Scaffolds are designed based on data from computed tomography, produced by selective laser melting from Ti-6Al-7Nb alloy powder and enriched with bioactive additives.
Direct Digital Additive Manufacturing and Cyber-Enabled Manufacturing Systems
Authors: Cooper Khershed P.
Published: July 2013

The technology of direct digital additive manufacturing (D2AM) has received considerable attention in recent months. Several government agencies and commercial interests are planning to explore D2AM to find solutions to manufacturing problems. The attraction of D2AM is the benefit of rapidly producing without fixtures or tools or human intervention customized objects of complex geometry not possible by traditional methods. The interest in D2AM ranges from fabrication of critical, high value aerospace metallic components to fabrication of objects having an organic look or as nature would have intendedi. For D2AM to be commercially accepted, it must reliably and predictably make products. It must achieve consistency in reproducibility across relevant D2AM methods. The Office of Naval Research (ONR) has launched a new basic research program, known as Cyber-enabled Manufacturing Systems (CeMS). The long-range goal of the program is to achieve the level of control over D2AM processes for industrial acceptance and wide-use of the technology. This program will develop measuring, sensing and control models and algorithms for D2AM by harnessing principles underpinning cyber-physical systems (CPS) and fundamentals of physical processes. This paper describes the challenges facing D2AM and the CeMS program goals to meet them.
Job Shop Scheduling to Meet Due Dates With Consideration to Sequence Dependent Setup Times in a Dynamic Environment
Authors: Eguchi Toru , Nishi Katsutoshi , Kawai Hiroaki , Murayama Takeshi
Published: July 2013

In this paper, we propose a dynamic job shop scheduling method to minimize tardiness with consideration to sequence dependent setup times. Schedules are optimized on a rolling basis using the mixture of genetic algorithm and switching priority rules. Both in genetic algorithm and switching rules, schedules are generated to increase due date allowances to be robust in dynamic environment. Numerical experiments show the effectiveness of the proposed method.
Shape Memory Alloy Actuated Vertical Deploy Air Dam: Part 1 — Performance Requirements and Design
Authors: Browne Alan L. , Johnson Nancy L. , Muhammad Hanif , Brown Jeffrey
Published: July 2013

Airflow over/under/around a vehicle can affect many important aspects of vehicle performance including vehicle drag (and through this vehicle fuel economy) and cooling/heat exchange for the vehicle powertrain and A/C systems. The vast majority of known devices in current use to control airflow over/under/around the vehicle are of fixed geometry, location, orientation, and stiffness. The project whose performance requirements, design, and build phases are described in this paper was successful in developing an SMA actuator based approach to the on-demand reversible deployment of an air dam through vertical translation. Beyond feasibility, the initial bench top working models demonstrated an active materials based approach which would add little weight to the existing stationary system, and could potentially perform well in the harsh under vehicle environment due to a lack of exposed bearings and pivots. This demonstration showed that actuation speed, force, and cyclic stability all could meet the application requirements. The solution, a dual point balanced actuation approach based on shape memory alloy wires, uses straight linear actuation to produce a reversible height change of 50 mm. Key technical issues with regard to design remaining to be resolved given the harsh under vehicle environment are in most part related to improved system robustness, a prime example being mechanism sealing.
Comparison of Inverse Algorithms for Delamination Detection in Composite Laminates
Authors: Zhang Zhifang , Ihesiulor Obinna Kenneth , Shankar Krishna , Ray Tapabrata
Published: July 2013

Delamination is a frequent and potentially serious damage that can occur in laminated polymer composites due to the poor inter-laminar fracture toughness of the matrix. Vibration based detection methods employ changes caused by loss of stiffness in dynamic parameters such as frequencies and mode shapes to detect and assess damage. Because it is a whole field method, and can be applied instantaneously and remotely, vibration monitoring using frequency measurements offers great potential for implementation in online structural health monitoring systems. However, one of the disadvantages of using frequency measurements is that while the presence of damage is easily identified through a shift in measured frequency, the determination of the location and the severity of the damage is not easy to accomplish. To determine the location and severity of damage from measured changes in frequency, it is necessary to solve the inverse problem, which requires the solution of a set of non-linear simultaneous equations.

In this paper, we have compared the performance of three different inverse algorithms for delamination detection in the fibre-reinforced composite laminates: direct of solution using a graphical method, artificial neural network (ANN) and surrogate-based optimization. In particular, the graphical method which was earlier proposed for problems of two variables has been extended to solution of three variables, the interface, location along the beam length and size of delamination in laminated composite beams. The three inverse algorithms have been compared using numerical validation data generated from the theoretical model of delaminated beam with and without artificial errors. All three algorithms can predict the delamination parameters accurately using the validation data directly generated from theoretical model. However, if artificial errors are introduced in the numerical data to simulate uncertainties in measurement of frequencies, ANN does not fare as well as the the other two methods as it is more sensitive to the artificial discrepancies. Also, ANN requires the network to be retrained if the measured frequency modes do not match the input modes in the existing network. The graphical technique and the surrogate based optimization performed equally well in the validations. However, the graphical technique is only applicable to no more than three variables, while the surrogate-based optimization algorithm can be applied to inverse problems with several unknown parameters such as in the case of delaminations in composite plates.
Application of Singular Spectrum Analysis to Bridge Structure Health Monitoring and Damage Detection
Authors: Loh Chin-Hsiung , Chao Shu-Hsien
Published: July 2013

Singular Spectrum Analysis (SSA) is a novel technique and has proven to be a powerful tool for time data series analysis. It takes singular value decomposition (SVD) of Hankel matrix embedded by analyzed time data series and decomposes the data into several simple, independent and identifiable components. In this paper, first, the coupling degree of the 1st and 2nd singular values through the composition of the analyzed signal in SSA is used as two important values to detect damage. Besides, based on the extracted sub-space or null-space from SVD of analytic matrix, damage detection algorithm is developed by considering the orthonormality between the sub-space and null-space. The proposed algorithms are verified using non-stationary response data of a model bridge (data from scouring test of a bridge) and field experiment of a bridge during abnormal weather condition. Discussion on the proposed methods with different assessment method to identify the occurrence of damage using SSI-DATA and SSI-COV to identified the system dynamic characteristics are also made.
Elastic Compensation of Linear Shape Memory Alloy Actuators Using Compliant Mechanisms
Authors: Mammano Giovanni Scirè , Dragoni Eugenio
Published: July 2013

The paper presents a modular architecture for SMA actuators elastically compensated by thin beams loaded axially beyond their buckling limit. Starting from the exact equations for the elastic curve of the beams, an approximate procedure is developed for the engineering design of the entire compensating system. The theory of the compensator is validated successfully against a finite element model and experimental results. The experimental characterization of a complete prototype actuator shows that the forces generated by the compensated actuator are constant for both instroke and outstroke over the full range of displacements. The actuator concept proposed lends itself to modular assembly to multiply either the stroke covered (series combination) or the force generated (parallel combination).
A Finite Element Study of Stable Crack-Growth in Superelastic Shape Memory Alloys
Authors: Parrinello Antonino , Baxevanis Theocharis , Lagoudas Dimitris , Cox Austin
Published: July 2013

A finite-element analysis of stable crack growth in superelastic Shape Memory Alloys (SMAs) is carried out for plane strain, mode I loading. The small-scale transformation assumption is employed in the calculations using displacement boundary conditions on a circular region that encloses the stress-induced phase transformation zone. The constitutive law adopts the classical rate-independent small-strain flow theory for the evolution equation of the transformation strains. The crack is assumed to propagate quasi-statically with the energy release rate maintained at a critical value; the analysis is accomplished by means of the Virtual Crack Closure Technique (VCCT). Resistance curves, obtained for a range of thermomechanical parameters, show enhanced fracture toughness.
Two-Phase Solid-Fluid Mathematical Model of Yield Stress Fluids
Authors: Peshkov Ilya , Grmela Miroslav , Romenski Evgeniy
Published: July 2013

In this work, we present results on mathematical modelling of polymeric yield stress fluids which have the properties of both elastic solids and fluids. Our research is based on the approach of multiphase continuum mechanics. A two-phase solid-fluid model is developed. This model is thermodynamically compatible and its governing differential equations can be written in a conservative form. Such a model is convenient for application of advanced high-accuracy numerical methods and modelling of discontinuous solutions such as shock waves and contacts.
Development of a Lumped-Parameter Occupant Injury Assessment Model for Vehicular Blast Effects Simulation
Authors: Yoo JinHyeong , Murugan Muthuvel , Le Dy
Published: July 2013

In this study, a lumped-parameter human body including lower leg in seated posture with a quarter-car model was developed for blast injury assessment simulation. To simulate the shock acceleration of the vehicle, mine blast analysis was conducted on a generic land vehicle crew compartment (sand box) structure. For the purpose of simulating human body dynamics, a physical model of lumped-parameter human body with a quarter car model was developed and implemented in multi-body dynamic simulation software. The injury criteria and tolerance levels for the biomechanical effects are discussed for each of the identified vulnerable body regions, such as the lower leg, the spine, and the neck. Passive seat and footrest damper devices were analytically evaluated to investigate their effectiveness for a seated occupant in a vehicle environment during a blast event. The seat damper has significant influence on the neck and the spine injury assessment values; however has less influence on the lower leg injury assessment value. For protecting the lower leg from injury, a separated footrest with a passive spring-damper system was more effective than the seat damper.
Passive Frequency Doubling Antenna Sensor for Wireless Strain Sensing
Authors: Yi Xiaohua , Cho Chunhee , Wang Yang , Cook Benjamin S. , Cooper James , Vyas Rushi , Tentzeris Manos M. , Leon Roberto T.
Published: July 2013

This paper presents the design, simulation, and preliminary measurement of a passive (battery-free) frequency doubling antenna sensor for strain sensing. Illuminated by a wireless reader, the sensor consists of three components, i.e. a receiving antenna with resonance frequency f0, a transmitting antenna with resonance frequency 2f0, and a matching network between the receiving and transmitting antennas. A Schottky diode is integrated in the matching network. Exploiting nonlinear circuit behavior of the diode, the matching network is able to generate output signal at doubled frequency of the reader interrogation signal. The output signal is then backscattered to the reader through the sensor-side transmitting antenna. Because the backscattered signal has a doubled frequency, it is easily distinguished by the reader from environmental reflections of original interrogation signal. When one of the sensor-side antennas, say receiving antenna, is bonded to a structure that experiences strain/deformation, resonance frequency of the antenna shifts accordingly. Through wireless interrogation, this resonance frequency shift can be measured by the reader and used to derive strain in the structure. Since operation power of the diode is harvested from the reader interrogation signal, no other power source is needed by the sensor. This means the frequency doubling antenna sensor is wireless and passive. Based on simulation results, strain sensitivity of this novel frequency doubling antenna sensor is around −3.84 kHz/με.