bluuebunny/crossref_metadata_2025 huggingface dataset:
Limitations in intense exercise performance of athletes – effect of speed endurance training on ion handling and fatigue development
Authors: Hostrup Morten , Bangsbo Jens
Published: September 2016

Mechanisms underlying fatigue development and limitations for performance during intense exercise have been intensively studied during the past couple of decades. Fatigue development may involve several interacting factors and depends on type of exercise undertaken and training level of the individual. Intense exercise (½–6 min) causes major ionic perturbations (Ca2+, Cl−, H+, K+, lactate− and Na+) that may reduce sarcolemmal excitability, Ca2+ release and force production of skeletal muscle. Maintenance of ion homeostasis is thus essential to sustain force production and power output during intense exercise. Regular speed endurance training (SET), i.e. exercise performed at intensities above that corresponding to maximum oxygen consumption (), enhances intense exercise performance. However, most of the studies that have provided mechanistic insight into the beneficial effects of SET have been conducted in untrained and recreationally active individuals, making extrapolation towards athletes’ performance difficult. Nevertheless, recent studies indicate that only a few weeks of SET enhances intense exercise performance in highly trained individuals. In these studies, the enhanced performance was not associated with changes in and muscle oxidative capacity, but rather with adaptations in muscle ion handling, including lowered interstitial concentrations of K+ during and in recovery from intense exercise, improved lactate−–H+ transport and H+ regulation, and enhanced Ca2+ release function. The purpose of this Topical Review is to provide an overview of the effect of SET and to discuss potential mechanisms underlying enhancements in performance induced by SET in already well‐trained individuals with special emphasis on ion handling in skeletal muscle.

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An Efficient Workflow for Production Allocation During Water Flooding
Authors: Azamipour Vahid , Assareh Mehdi , Dehghani Mohammad Reza , Mittermeir Georg M.
Published: September 2016

This paper presents an efficient production optimization scheme for an oil reservoir undergoing water injection by optimizing the production rate for each well. In this approach, an adaptive version of simulated annealing (ASA) is used in two steps. The optimization variables updating in the first stage is associated with a coarse grid model. In the second step, the fine grid model is used to provide more details in final solution search. The proposed method is formulated as a constrained optimization problem defining a desired objective function and a set of existing field/facility constraints. The use of polytope in the ASA ensures the best solution in each iteration. The objective function is based on net present value (NPV). The initial oil production rates for each well come from capacity and property of each well. The coarse grid block model is generated based on average horizon permeability. The proposed optimization workflow was implemented for a field sector model. The results showed that the improved rates optimize the total oil production. The optimization of oil production rates and total water injection rate leads to increase in the total oil production from 315.616 MSm3 (our initial guess) to 440.184 MSm3, and the recovery factor is increased to 26.37%; however, the initial rates are much higher than the optimized rates. Beside this, the recovery factor of optimized production schedule with optimized total injection rate is 3.26% larger than the initial production schedule with optimized total water injection rate.
Designing Three-Dimensional Directional Well Trajectories Using Bézier Curves
Authors: Sampaio Jorge H. B.
Published: September 2016

A relatively simple, general, and very flexible method to design complex, three-dimensional hole trajectories can be obtained by using a 3D extension for Bézier curves. This approach offers superior results in terms of coding, use, and flexibility compared to other methods using double-arc, cubic functions, spline-in-tension functions, or constant curvature. The mathematics is surprisingly simple, and the method can be used to obtain trajectories for any of the four typical end conditions in terms of inclination and azimuth, namely: free-end, set-end, set-inclination/free azimuth, and free-inclination/set-azimuth. The resulting trajectories are smooth, with continuous and smooth change of curvature and toolface, better exploiting the expected delivery of modern rotary steerable deviation tools, particularly the point-the-bit and the push-the-bit systems. With the relevant parameters at any point of the trajectory (curvature and toolface angle) an automated system can steer the hole toward the defined targets in a smooth fashion. The beauty of the method is that the description of the trajectory is obtained with one single expression that handles the three space coordinates, instead of working with three separate coordinate functions. It uses a generalization of the well-known 2D Bézier curve. The concept is easy to understand, and implementation even using spreadsheets is straightforward. Besides, the conditions at both ends (coordinates and inclination/azimuth for set ends) the trajectory curve has up to two independent parameters. By playing suitably with these parameters, one can obtain a curve that favors the reduction of drag and torque during drilling, tripping, and casing running. In addition to the formulation for trajectory calculation, the paper presents the expressions to calculate the inclination, azimuth, curvature, and toolface at any point along the trajectory. Proper numerical examples illustrate the various end-conditions. The method can be used during the hole planning cycle as well as during the hole drilling for automatic and manual steerage.
Homotopy Perturbation Method for the Analysis of Heat Transfer in an Annular Fin With Temperature-Dependent Thermal Conductivity
Authors: Roy Rishi , Ghosal Sujit
Published: September 2016

A recent mathematical technique of homotopy perturbation method (HPM) for solving nonlinear differential equations has been applied in this paper for the analysis of steady-state heat transfer in an annular fin with temperature-dependent thermal conductivity and with the variation of thermogeometric fin parameters. Excellent benchmark agreement indicates that this method is a very simple but powerful technique and practical for solving nonlinear heat transfer equations and does not require large memory space that arises out of discretization of equations in numerical computations, particularly for multidimensional problems. Three conditions of heat transfer, namely, convection, radiation, and combined convection and radiation, are considered. Dimensionless parameters pertinent to design optimization are identified and their effects on fin heat transfer and efficiency are studied. Results indicate that the heat dissipation under combined mode from the fin surface is a convection-dominant phenomenon. However, it is also found that, at relatively high base temperature, radiation heat transfer becomes comparable to pure convection. It is worth noting that, for pure radiation condition, the dimensionless parameter of aspect ratio (AR) of a fin is a more desirable controlling parameter compared to other parameters in augmenting heat transfer rate without much compromise on fin efficiency.
Modeling and Performance Identification for General Production System Using Sensor Data
Authors: Zou Jing , Chang Qing , Lei Yong , Arinez Jorge , Xiao Guoxian
Published: September 2016

The productivity and efficiency of production systems are greatly influenced by their configuration and complex dynamics subject to constant changes caused by technology insertion, engineering modification, as well as disruption events. In this paper, we develop a mathematical model of production systems with general structure (tandem line, parallel, and etc.) to estimate the status of the system (production counts and processing speeds of the stations, buffer levels and production loss) by using sensor data of disruption events. Real-time production system performance such as effective disruption events, opportunity window, and permanent production loss are identified, which is very useful in real-time control to increase overall system efficiency.
Rock Cutter Interactions in Linear Rock Cutting
Authors: Che Demeng , Zhang Weizhao , Ehmann Kornel F.
Published: September 2016

Polycrystalline diamond compact (PDC) cutter, as a major cutting tool, has been widely applied in oil and gas drilling processes. The understanding of the complex interactions at the rock and cutter interfaces are essential for the advancement of future drilling technologies, yet, these interactions are still not fully understood. Linear cutting of rock, among all the testing methods, avoids the geometric and process complexities and offer the most straightforward way to reveal the intrinsic mechanisms of rock cutting. Therefore, this paper presents an experimental study of the cutter’s cutting performance and the rock’s failure behaviors on a newly developed linear rock cutting facility. A series of rock cutting tests were designed and performed. The acquired experimental data was analyzed to investigate the influences of process parameter and the rock’s mechanical properties on chip formation and force responses.
Three Dimensional Point Cloud Measurement Based Dimensional Integrity Assessment for Additive Manufactured Parts Using Spectral Graph Theory
Authors: Rao Prahalad K. , Kong Zhenyu , Duty Chad E. , Smith Rachel J.
Published: September 2016

The ability of additive manufacturing (AM) processes to produce components with virtually any geometry presents a unique challenge in terms of quantifying the dimensional quality of the part. In this paper, a novel spectral graph theory (SGT) approach is proposed for resolving the following critical quality assurance concern in AM: how to quantify the relative deviation in dimensional integrity of complex AM components. Here, the SGT approach is demonstrated for classifying the dimensional integrity of standardized test components. The SGT-based topological invariant Fiedler number (λ2) was calculated from 3D point cloud coordinate measurements and used to quantify the dimensional integrity of test components. The Fiedler number was found to differ significantly for parts originating from different AM processes (statistical significance p-val. < 1%). By comparison, prevalent dimensional integrity assessment techniques, such as traditional statistical quantifiers (such as mean and standard deviation) and examination of specific facets/landmarks failed to capture part-to-part variations, and thus proved incapable of ranking the quality of test AM components in a consistent manner. In contrast, the SGT approach was able to consistently rank the quality of the AM components with a high degree of statistical confidence independent of sampling technique used. Consequently, from a practical standpoint, the SGT approach can be a powerful tool for assessing the dimensional integrity of AM components, and thus encourage wider adoption of AM capabilities.
Smooth Cornering Strategy for High Speed CNC Machine Tools With Confined Contour Error
Authors: Tajima Shingo , Sencer Burak
Published: September 2016

Conventional tool-paths for CNC (computer numerical controlled) machine tools or NC positioning systems are mainly composed of linear motion segments, or so called the G1 commands. Interpolating along linear tool-paths exhibits serious limitations in terms of achieving the desired part geometry and productivity in high-speed machining. Velocity and acceleration discontinuities occur at the junction points of consecutive segments. In order to generate smooth and continuous feed motion, a kinematic corner smoothing algorithm is proposed in this paper, which plans smooth acceleration and jerk profiles around the segment junction to realize continuous velocity transition between consecutive linear segments. The proposed corner-smoothing algorithm eliminates the need for geometry based corner-blending techniques and presents a computationally efficient interpolation scheme. The cornering error is controlled analytically allowing the end-user to control the cornering tolerance. Drive’s acceleration and the jerk limits are fully utilized to minimize overall cornering duration. This delivers a time optimal cornering motion within user specified cornering error tolerances. Simulation studies are used to demonstrate the effectiveness of proposed high-speed cornering scheme.
Research on Ultrasonic Aided Fixed-Abrasive Lapping Technology for Engineering Ceramics Cylindrical Part
Authors: Jiao Feng , Zhao Bo
Published: September 2016

As the final machining procedure of precision components, lapping is often regarded as an important step affecting surface quality, machining accuracy and machining efficiency. Due to some drawbacks of free-abrasive lapping such as deep scratches on the lapped surface, lower lapping efficiency for lower lapping speed, severe waste of abrasive, high processing cost, and so on, fixed-abrasive lapping technology was put forward and developed recently. Meanwhile, considering the unique advantages of the ultrasonic vibration aided machining in the processing of hard-brittle materials such as engineering ceramics, optical glass, etc. and the influence of ultrasonic vibration on the self-sharpening characteristic of abrasive pellet, a novel ultrasonic aided fixed-abrasive lapping technology for engineering ceramics cylindrical part is put forward and corresponding lapping device is developed in this paper. Through theoretical analysis on the ultrasonic aided lapping mechanism, it is found that the value and direction of grain movement speed will change due to the superimposition of ultrasonic vibration, which will lead to the change of cutting angles and further affect the lapping performance. Assuming every abrasive particle is a cutting insert, under the assistance of axial ultrasonic vibration, negative rake of the grain will increase, even change to positive value, so as to sharpen the lapping grains and benefit the lapping processing. Moreover, when ultrasonic vibration is superimposed to the lapping tool, motion locus of abrasive grains will present sinusoid. As a result, the locus of single grain may self-interfere in actual lapping process and make blank cutting. So the depth of cut of abrasive grain will increase under the same lapping pressure, leading to the increase of MRR under the same lapping conditions. Finally, a series of contrast lapping experiments were carried out and some lapping characteristics were researched. Experimental results show that ultrasonic vibration assistance can help to heighten material removal rate, smoothen the waveform of tangential force, reduce the average tangential force and improve surface quality. Ultrasonic aided lapping with fixed abrasive is a high efficiency and precision processing technology for engineering ceramics cylindrical part.
Study of Ultrasonic Assisted Turning of 4340 Steel With Plane and Self-Lubricating Cutting Inserts
Authors: Sharma Varun , Pandey Pulak Mohan
Published: September 2016

The machining of intractable materials result in several problems that are required to be addressed for industry. The conventional turning of such materials is characterized by low material removal rate, which ultimately hampers the productivity. The present research work focuses on enhancing the machinability of Ultrasonic Assisted Turning (UAT) using self-lubricating cutting inserts. The formation of a thin lubricating layer combined with the aerodynamic lubrication is found to be responsible for decrease in the frictional force. A comparative study has been presented between plane and self-lubricating cutting insert over a range of cutting speed. The study of cutting force, surface roughness, shear angle and coefficient of friction demonstrate the better machining regime using textured cutting inserts during UAT. The chip analysis has been provided to indicate chip coiling due to the superimposition of ultrasonic vibration on the cutting insert.
Design and Modeling of a Microscale Selective Laser Sintering System
Authors: Roy Nilabh , Yuksel Anil , Cullinan Michael
Published: September 2016

The development of micro and nanoscale additive manufacturing methods in metals and ceramics is important for many applications in the aerospace, medical device, and electronics industries. Unfortunately, most commercially available metal additive manufacturing tools have feature-size resolutions of greater than 100 μm, which is too large to precisely control the microstructure of the parts they produce. A few research-grade metal additive manufacturing tools do exist, but their build rate is generally too slow for commercial applications. Therefore, this paper presents a new microscale selective laser sintering (μ-SLS) that can be used to improve the minimum feature-size resolution of metal additively manufactured parts by up to two orders of magnitude, while still maintaining the throughput of traditional additive manufacturing processes. In order to achieve this goal, several innovative design features like the use of (1) ultra-fast lasers, (2) a micro-mirror based optical system, (3) nanoscale powders, and (4) a precision spreader mechanism, have been implemented. The micro-SLS system is capable of achieving build rates of approximately 1 cm3/hr while achieving a feature-size resolution of approximately 1 μm. This paper will also present new molecular scale models that have been developed for the micro-SLS to quantify and certify the micro-SLS build process. Modeling of the micro-SLS process is challenging, because most macroscale models of the SLS process contain assumptions that are no longer valid when the size of the particles that are being sintered is smaller than the wavelength of the laser being used to sinter them. Therefore, in modeling the micro-SLS process we must account for the wave nature of light and can no longer rely on the ray tracing models commonly used to model the SLS process. Also, heat transfer in the micro-SLS process is dominated by near-field radiation due to the diffraction of the light off the nanoparticles in the powder bed and the ultrafast lasers that are used in the micro-SLS system. This means that the assumptions of heat transfer by conduction and far-field radiation in the macroscale SLS systems are no longer valid for the micro-SLS system. Finally, the agglomeration of nanoparticles in the powder bed must be accurately modeled in order to precisely predict the formation of defects in the final parts produced. Overall, the goal of this modeling effort is to be able to predict the quality of a part produced using any given processing conditions, in order to produce parts that are “born certified” and do not need to be tested post fabrication.
Manufacturing Supplier Selection in Cloud Manufacturing Context and its Implementation and Application Perspectives
Authors: Hassanzadeh Soheil , Cheng Kai
Published: September 2016

Nowadays, many companies have decided to use other companies’ competencies and outsource part of their manufacturing and business processes to suppliers from abroad in order to reduce costs, improve quality of products, and offer better services to customers. On the other hand, this decision has faced organizations with new challenges. Organizations need to evaluate their supplier’s performance, and consider their weakness and strength to survive in high competitive markets.

In addition, cloud manufacturing, as a powerful tool will likely enable small and medium sized enterprises (SMES) to move towards using dynamic scalability and ‘free’ available data resources in a virtual manner and to provide solution-based, value-added, digital-driven manufacturing service over the Internet. The research presented in this paper aims to develop a supplier selection framework in the context of cloud manufacturing. The paper will present the background and concept of supplier selection following by proposed framework which consisted of four modules, multi-criteria module, bidding module, optimization module, and learning module. Finally, web based supplier selection approach will be briefly presented as it is not the main aim of this paper.
Advances in Quality and Productivity in Precision Grinding: A Review of Selected Research
Authors: Chen Xun , Morgan Michael N.
Published: September 2016

This paper reviews grinding research led by Professor W Brian Rowe at Liverpool John Moores University and at other establishments previously. Research reviewed extends over fundamentals of grinding processes and machine performance carried out over fifty-five years. Topics range from accuracy in centreless grinding and other grinding processes to grinding machine behaviour and high precision grinding machine design including bearing technology. Research also ranges to high-removal rate grinding processes, surface integrity and intelligent process control. This review highlights progress in selected areas and demonstrates that improving product quality allows improved manufacturing productivity.
A Hybrid RF-GA Approach to Bottleneck Machine Diagnosis and Suggestion in Parallel Machine Job-Shop Scheduling
Authors: Rajora Manik , Zou Pan , Liang Steven
Published: September 2016

In this paper, a hybrid Random Forest-Genetic Algorithm approach to detect and solve bottleneck machine problems in parallel machine Job-shop scheduling is developed with the aim of minimizing the makespan and the additional cost. The drawbacks of the existing methods for diagnosing bottlenecks is that they either do not consider the severity of the bottleneck or they do not consider the existence of multiple bottlenecks. In the existing models for solving bottlenecks, the cost is not considered as an objective function and only shifting of bottlenecks is utilized to solve the bottleneck machine problem. This approach is not feasible if the maximum capacity of the workshop has been reached. In this paper, a Random Forest classification model is utilized to diagnose bottleneck machine with different severity where the severity of the machines on the shop floor can either be none, low, medium, or high. Due to the lack of historical data, the Random Forest algorithm is trained using bottleneck data generated by simulating several identical parallel machine Job-shop scheduling problems. The trained Random Forest algorithm is then used in conjunction with Genetic Algorithm for finding the optimal actions to be taken for the most severe bottlenecks machines in order to reduce the makespan and the additional cost by optimizing the number of additional parallel machines to be utilized and overtime hours for the most severe bottleneck machines. The two objectives, makespan and additional cost, are combined into a single objective value by the use of weight values. These weight values depend on severity of the most severe bottleneck machine. If the bottleneck severity is “high” then makespan has a higher weight value than cost, if the severity is “medium” then both cost and makespan are weighed equally, and if the severity is “low” then cost has a higher weight value than makespan. In order to show the validity of the proposed approach it is used for diagnosing and solving the bottleneck problems in three different identical parallel machine Job-shop scheduling case studies 1. 3 jobs with 6 machines 2. 5 jobs with 9 machines and 3. 5 jobs with 12 machines. By utilizing the proposed approach the makespan and cost were reduced by 19.0%, 24.5% and 25.4% in case studies 1, 2, and 3 respectively. The results show that the trained Random Forest algorithm was able to correctly diagnose the bottleneck machines and their severity and Genetic algorithm was able to find the optimal number of additional hours and additional machines for the most severe bottleneck machines on the shop floor.
Finite Element Modeling of Selective Laser Melting 316L Stainless Steel Parts for Evaluating the Mechanical Properties
Authors: Ahmadi Arman , Shayesteh Moghaddam Narges , Elahinia Mohammad , Karaca Haluk E. , Mirzaeifar Reza
Published: September 2016

Selective laser melting (SLM) is an additive manufacturing technique in which complex parts can be fabricated directly by melting layers of powder from a CAD model. SLM has a wide range of application in biomedicine and other engineering areas and it has a series of advantages over traditional processing techniques. A large number of variables including laser power, scanning speed, scanning line spacing, layer thickness, material based input parameters, etc. have a considerable effect on SLM process materials. The interaction between these parameters is not completely studied. Limited studies on balling effect in SLM, densifications under different processing conditions, and laser re-melting, have been conducted that involved microstructural investigation. Grain boundaries are amongst the most important microstructural properties in polycrystalline materials with a significant effect on the fracture and plastic deformation. In SLM samples, in addition to the grain boundaries, the microstructure has another set of connecting surfaces between the melt pools. In this study, a computational framework is developed to model the mechanical response of SLM processed materials by considering both the grain boundaries and melt pool boundaries in the material. To this end, a 3D finite element model is developed to investigate the effect of various microstructural properties including the grains size, melt pools size, and pool connectivity on the macroscopic mechanical response of the SLM manufactured materials. A conventional microstructural model for studying polycrystalline materials is modified to incorporate the effect of connecting melt pools beside the grain boundaries. In this model, individual melt pools are approximated as overlapped cylinders each containing several grains and grain boundaries, which are modeled to be attached together by the cohesive zone method. This method has been used in modeling adhesives, bonded interfaces, gaskets, and rock fracture. A traction-separation description of the interface is used as the constitutive response of this model. Anisotropic elasticity and crystal plasticity are used as constitutive laws for the material inside the grains. For the experimental verification, stainless steel 316L flat dog bone samples are fabricated by SLM and tested in tension. During fabrication, the power of laser is constant, and the scan speed is changed to study the effect of fabrication parameters on the mechanical properties of the parts and to compare the result with the finite element model.
Fabrication of Custom Pattern Reinforced AZ31 Multilayer Composite Using Ultrasonic Spray Deposition
Authors: Bastwros Mina , Kim Gap-Yong
Published: September 2016

Mimicking the unique hierarchical, multiscale structures of natural biological materials is a promising approach to create novel materials with outstanding properties. One of the challenges, however, is the lack of scalable fabrication methods capable of making such complex structures. In this study, a multilayer nanocomposite has been synthesized by incorporating an ultrasonic spray deposition technique. The spray deposition system was used to deposit nanoparticles on substrate foils, which were consolidated to synthesize the multilayer composite. A patterned mask was used to create micro-patterns with nanoscale structures. A magnesium alloy, AZ31, foils were used as the matrix material. A mixture of nano-silicon carbide (nano-SiC) and aluminum alloy, Al6061, particles was used as the reinforcement phase in the deposited patterns. A three point bend test and a small punch test were carried out to evaluate the mechanical properties. A multilayer composite consisting of circular micro-patterns with SiC nano-structure was successfully created. The patterned composite showed an enhancement in the flexural yield strength and the flexural ultimate strength of 43% and 30% respectively, compared with the uniform multilayer composite without the patterns.
Rotary Ultrasonic Drilling of CFRP: Effect of Process Parameters on Delamination
Authors: Fernando Palamandadige K. S. C. , Pei Zhijian , Zhang Meng (Peter) , Song Xiaoxu
Published: September 2016

Drilling is an essential practice, especially for the aerospace industry. Conventional machining procedures such as twist drilling are not cost effective for hard to machine materials such as titanium, advanced ceramics, carbon fiber reinforced plastics etc. Rotary ultrasonic machining (RUM) is a nontraditional machining process for hard to machine materials. RUM utilizes a rotating, ultrasonically vibrating tool (core drill) feeds into the workpiece to remove the material. Although drilling is the most common machining process for CFRP, delamination is a major problem associated with drilling, because of its heterogeneity and anisotropy. Delamination reduces structural integrity and increases assembly tolerance which leads to rejection of a part or a component. In the air craft industry, rejections caused by delamination accounts for 60% of all rejections in final assembly. This motivates researchers to identify delamination-free techniques to reduce component rejection caused due to delamination. This paper, for the first time, investigates the effects of process parameters on the delamination of CFRP processed by RUM. These process parameters are variable feed rate, variable spindle speed and the use of backing plate.
Automated Assembly of Electronic Digital Materials
Authors: Langford Will , Ghassaei Amanda , Gershenfeld Neil
Published: September 2016

Interest in additive manufacturing has recently been spurred by the promise of multi-material printing and the ability to embed functionality and intelligence into objects. Here, we present an alternative to additive manufacturing, introducing an end-to-end workflow in which discrete building blocks are reversibly joined to produce assemblies called digital materials. We describe the design of the bulk-material building blocks and the devices that are assembled from them. Further, we detail the design and implementation of an automated assembler, which takes advantage of the digital material structure to restore positioning errors within a large tolerance. To generate assembly sequences, we use a novel CAD/CAM workflow for designing, simulating, and assembling digital materials. Finally, we evaluate the structures assembled using this process, showing that the joints perform well under varying conditions and that the assembled structures are functionally precise.
Flexible, Robot Guided Single-Pass Honing
Authors: Uhlmann Eckart , Zimmermann Sascha
Published: September 2016

In manufacturing, honing is used to meet high demands on shape and dimensional accuracy, surface quality, as well as tribological properties. In particular, honing of workpieces with bore holes in various positions and angles represents a challenge. With the help of a 6-axis industrial robot, a W-shaped compressor body was machined and experimental results were compared with results produced by a machining center.
Scalable Plasmonic Nanolithography: Prototype System Design and Construction
Authors: Wang Yuan , Saad Mohamed E. , Ni Kang , Chang Yen Chi , Chen Cheng-Wei , Chen Chen , Pan Liang , Tsao Tsu Chin , Lavine Adrienne S. , Bogy David B. , Zhang Xiang
Published: September 2016

Maskless nanolithography is an agile and cost effective approach if their throughputs can be scaled for mass production purposes. Using plasmonic nanolithography (PNL) approach, direct pattern writing was successfully demonstrated with around 20 nm half-pitch at high speed. Here, we report our recent efforts of implementing a high-throughput PNL prototype system with unique metrology and control features, which are designed to use an array of plasmonic lenses to pattern sub-100 nm features on a rotating substrate. Taking the advantage of air bearing surface techniques, the system can expose the wafer pixel by pixel with a speed of ∼10 m/s, much faster than any conventional scanning based lithography system. It is a low-cost, high-throughput maskless approach for the next generation lithography and also for the emerging nanotechnology applications, such as nanoscale metrology and imaging.
Vision-Based Inspection System for Dimensional Accuracy in Powder-Bed Additive Manufacturing
Authors: Aminzadeh Masoumeh , Kurfess Thomas
Published: September 2016

Laser powder-bed fusion (L-PBF) is an additive manufacturing (AM) process that enables fabrication of functional metal parts with near-net-shape geometries. The drawback to L-PBF is its lack of dimensional precision and accuracy. The efficiency of powder fusion process in powder-bed AM processes is highly affected by process errors, powder irregularities as well as geometric factors. Formation of defects such as lack of fusion and over-fusion due to the aforementioned factors causes dimensional errors that significantly damage the precision.

This paper addresses the development of an automated in-situ inspection system for powder-bed additive manufacturing processes based on machine vision. The results of the in-situ automated inspection of dimensional accuracy allows for early identification of faulty parts or alternatively in-situ correction of geometric errors by taking appropriate corrective actions. In this inspection system, 2D optical images captured from each layer of the AM part during the build are analyzed and the geometric errors and defects impairing the dimensional accuracy are detected in each layer. To successfully detect geometric errors, fused geometric objects must be detected in the powder layer. Image processing algorithms are effectively designed to detect the geometric objects from images of low contrast captured during the build inside the chamber. The developed algorithms are implemented to a large number of test images and their performance and precision are evaluated quantitatively. The failure probabilities for the algorithms are also determined statistically.
Effects of Laser Shock Peening on the Wear and Degradation Behaviors of Magnesium Alloys
Authors: Zhang Ruixia , Hou Xiaoning , Zhou Xianfeng , Gao Hongyu , Mankoci Steven , Qin Haifeng , Ren Zhencheng , Doll Gary L. , Martini Ashlie , Dong Yalin , Sahai Nita , Ye Chang
Published: September 2016

In this study, we investigated the mechanical properties of AZ31B Mg alloy before and after laser shock peening (LSP). The hardness of the AZ31B Mg alloy increased from 57 HV to 69 HV after LSP. The yield strength increased from 128 MPa to 152 MPa. Wear resistance was significantly improved after LSP. Immersion testing showed that LSP did not significantly increase the element release and weight loss in simulated body fluid. We have demonstrated that LSP is an effective way to improve the mechanical properties of the AZ31B Mg alloy.
Needle Cutting of Skin Simulants
Authors: Barnett Andrew C. , Tan Lei , Barrett Jessica , Moore Jason Z.
Published: September 2016

Tissue simulants are commonly used in medical procedure training and research to test the insertion and cutting mechanics of medical devices. Accurate representation of the forces and tissue properties is important for the efficacy of the training and research studies. This paper provides a quantitative method of determining the performance of tissue simulants. A force model was used to determine the three component forces: tearing, spreading, and friction forces, of a needle passing through six different skin simulants. Experiments were performed to determine the fracture toughness, shear modulus, friction between the simulant and needle, and the crack length in the simulant made by the needle. Polyurethane with Shore hardness 40 A was shown to be the best simulant by having the composition of forces most similar to porcine skin tissue: 39% and 61% for the tearing force, 18% and 32% for the spreading force, and 29% and 21% for the friction force for the polyurethane and porcine skin respectively.
Investigation on the Grinding Force, Power and Heat Flux Distributions Along the Tooth Profile in Form Grinding of Gears
Authors: Jin Tan , Yi Jun , Cai Rui
Published: September 2016

This paper investigates the distributions of grinding force, power consumption and heat flux along the tooth profile in precision form grinding of gears. A semi-analytical grinding force model has been established considering the static and dynamic chip formation forces and also the sliding force. Variation of the local contact conditions between the wheel and gear flank along the gear tooth profile, including the local depth of cut, local wheel diameter, local wheel speed and also the equivalent wheel diameter has been analyzed. Combining the variation of local contact conditions with the semi-analytical grinding force model, the grinding force and power distributions along the gear tooth profile have been derived. The predicted values of grinding power under different wheel speeds, worktable speeds, radial grinding depths and different contact widths are compared with those experimentally obtained and the results show a reasonable agreement. The predicted grinding forces at different rolling angle positions under different grinding parameters show a good agreement when compared with those experimentally obtained. The heat flux distribution along the interface between the form grinding wheel and the gear flank in form gear grinding has been further calculated.
Methodology to Improve the Cylindricity of Engine Cylinder Bore by Honing
Authors: Zhang Xueping , Wang Xiaoqin , Wang Daming , Wang Xiaojuan , Yao Zhenqiang , Xi Lifeng
Published: September 2016

Cylindricity of engine cylinder bore is identified as one of crucial factors to exert great influence on engine performance such as piston friction and wear, energy consumption and emission. Cylindricity at macroscopic level as well as surface roughness at micro-level such as peak roughness, core roughness and valley roughness for engine cylinder bore is typically generated by honing operation. However, the selection of the process parameters of honing is currently based on empirical methods since honing is mechanically complex. It thus makes a significance to analytically investigate honing operation to significantly improve the cylindricity of engine cylinder bore based on its function requirements. This research aims to explore the methodology on achieving the desired cylindricity for engine cylinder bore through several approaches including simulating honing motion trajectory, improving honing head structure, coordinating honing with its previous boring operation, and optimizing honing parameters including honing speed, feed rate, overrunning distance. This research aims to provide a systematical thinking to achieve macro-geometrical features in honing engine cylinder bore and a theoretical approach for the selection and optimization of honing process parameters.
Industrial Cloud Robotics Towards Sustainable Manufacturing
Authors: Liu Jiayi , Xu Wenjun , Zhang Jiaqiang , Zhou Zude , Pham Duc Truong
Published: September 2016

Cloud Robotics (CR) is the combination of Cloud Computing and Robotics, which encapsulate resources related with robots as services and is also the robotics’ next stage of development. Under this background, due to the characteristics of convenient access, resource sharing and lower costs, industrial cloud robotics (ICR) is proposed to integrate the industrial robots resources in the worldwide to provide ICR services in worldwide. ICR also plays an important role in improving the productivity of manufacturing. In the manufacturing field, Cloud Manufacturing (CM) and Sustainable Manufacturing (SM) is the developing orientation of future manufacturing industry. The energy consumption optimization of ICR is the crucial issue for manufacturing sustainability. However, currently, ICR systems are not programmed efficiently, which leads to the increase of production costs and pollutant emissions. Thus, it is an actual problem to optimize the energy consumption of ICR. In this paper, in order to achieve the goal of energy consumption optimization in worldwide range, the framework of ICR towards sustainable manufacturing is presented, as well as its enabling methodologies, and it is used to support energy consumption optimization services of ICR in the Cloud environment. This framework can be used to support energy-efficient services related with ICR to realize sustainable manufacturing in the worldwide range.
Experimental Study on Environmentally-Friendly Micro End-Milling Process of Ti-6Al-4V Using Nanofluid Minimum Quantity Lubrication With Chilly Gas
Authors: Kim Jung Sub , Kim Jin Woo , Kim Young Chang , Lee Sang Won
Published: September 2016

This research experimentally investigates the characteristics of micro end-milling process of titanium alloy using nanofluid minimum quantity lubrication (MQL) with chilly CO2 gas. In the nanofluid MQL, hexagonal boron nitride (hBN) particles having a lamellar structure are used. They have high aspect ratio and enable sliding against other particles, which can provide better lubricity. In addition, the chilly CO2 gas enhances a cooling effect during the micro end-milling process. A series of micro end-milling experiments are conducted in the meso-scale machine tool system, and milling force, coefficient of friction, surface roughness and tool wear are observed and analyzed according to varying lubrication and cooling conditions. The results show that the nanofluid MQL with chilly gas can be effective for reducing milling forces, coefficient of friction, tool wear and improving surface quality.
Cloud Manufacturing: An Industry Survey
Authors: Zang Tiegang , Liu Yongkui , Xu Xun
Published: September 2016

The emerging business technology trends such as cloud, Internet of Things, and the new requirements and challenges of future development of manufacturing industry such as green manufacturing and knowledge innovations, have together given rise to a novel cloud-based service-oriented manufacturing business model — cloud manufacturing. Since its inception, cloud manufacturing has attracted much attention of researchers from both academia and industry. As a nascent concept aiming to achieve comprehensive and full resource sharing and e-business collaboration, the success of cloud manufacturing depends heavily on the support and participation of industrial enterprises. However, so far there have been few reports on the status of cloud manufacturing among industrial enterprises. In order to understand the situation of cloud manufacturing in industry, we conducted a survey with respect to its acceptability and application prospect among enterprises located in Jiangsu province, China. This paper presents the results of the survey and some analysis.
Application of Barlat Yld-96 Yield Criterion for Predicting Formability of Pre-Strained Dual Phase Steel Sheets
Authors: Basak Shamik , Panda Sushanta Kumar
Published: September 2016

The selection of advanced material model considering the anisotropy mechanical properties of the thin sheet is vital in order to estimate stress based forming limit diagram (σ-FLD). In present study associative plasticity theory was applied indulging Barlat Yld-96 anisotropy yield function and the Swift hardening law was implemented for estimating the limiting stresses from the conventional strain FLD (ε-FLD) of an automotive grade dual phase steel DP600. Three different approaches were made to evaluate Yld-96 anisotropy coefficients using experimental results of stack compression and tensile tests. To impose complex strain path, two stage stretch forming processes were simulated in finite element solver LS-DYNA. After biaxial pre-straining, the sample geometries were varied to achieve different strain paths during the second stage of deformation. The results indicated that there was negligible difference in limiting stress estimated by Yld-96 plasticity theory when the anisotropy coefficients were calculated based on plastic strain at ultimate tensile strength compare to that by minimum plastic work method. It was concluded that the dynamic shift of ε-FLD could be restricted by σ-FLD estimated using Yld 96 plasticity theory, and hence it was proposed to be a suitable damage model to evaluate formability of pre-strained DP600 steels.
Investigation of Thermo-Mechanical Processing and Mechanical Properties of CoCrFeNiMn High Entropy Alloy for Peripheral Vascular Stent Application
Authors: Alagarsamy Karthik , Fortier Aleksandra , Mishra Rajiv , Kumar Nilesh
Published: September 2016

High entropy alloys (HEAs) are a new class of metallic materials with five or more principal alloying elements. Due to this distinct concept of alloying, the HEAs exhibit unique properties compared to conventional alloys. The outstanding properties of HEAs include increased strength, superior wear resistance, high temperature stability, increased fatigue properties, good corrosion and oxidation resistance. Such characteristics of HEAs have generated significant interest among the scientific community however, their application is yet to be explored. This paper discusses the mechanical and microstructural behavior of CoCrFeNiMn HEA subjected to thermo-mechanical processing, and its potential application in peripheral vascular stent implants that are prone to high failure rate. Results show that CoCrFeNiMn has characteristics that can potentially find use in peripheral vascular stent implants and extend their life-cycle.
Feature-Based Adaptive Manufacturing Equipment Control for Cloud Environments
Authors: Adamson Göran , Wang Lihui , Holm Magnus , Moore Philip
Published: September 2016

The ideas of on-demand, scalable and pay-for-usage resource-sharing in Cloud Manufacturing are steadily attracting more interest. For implementing the concept of Manufacturing-as-a-Service in a cloud environment, description models and implementation language for resources and their capabilities are required. A standardized approach for systemized virtualization, servisilisation, retrieval, selection and composition into higher levels of functionality is necessary. For the collaborative sharing and use of networked manufacturing resources there is also a need for a control approach for distributed manufacturing equipment.

In this paper, the technological perspective for an adaptive cloud service-based control approach is described, and a supporting information model for its implementation. The control is realized through the use of a network of intelligent and distributable Function Block decision modules, enabling run-time manufacturing activities to be performed according to actual manufacturing conditions. The control system’s integration to the cloud service management functionality is described, as well as a feature-level capability model and the use of ontologies and the Semantic Web.