bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Synthesis of Nanofibrous Nonwoven Carbon Components: Initial Observations, Capabilities and Challenges
Authors: Atwater Mark A. , Welsh Roger J.
Published: September 2016

Wide-spread adoption of carbon nanomaterials has been hindered by inefficient production and utilization. A recently developed method has shown possibility to directly synthesize bulk nanostructured nonwoven materials from catalytically deposited carbon nanofibers. The basic manufacturing scheme involves constraining carbon nanofiber growth to create three-dimensionally featured, macroscale products. Although previously demonstrated as a proof of concept, the possibilities and pitfalls of the method at a larger scale have not yet been explored. In this work, the basic foundation for using the constrained formation of fibrous nanostructures (CoFFiN) process is established by testing feasibility in larger volumes (as much as 2000% greater than initial experiments) and by noting the macroscale carbon growth characteristics. It has been found that a variety of factors contribute to determining the basic qualities of the macroscale fiber collection (nonwoven material), and there are tunable parameters at the catalytic and constraint levels. The results of this work have established that monolithic structures of nonwoven carbon nanofibers can be created with centimeter dimensions in a variety of cross-sectional shapes. The only limit to scale noted is the tendency for nanofibers to entangle with one another during growth and self-restrict outward expansion to the mold walls. This may be addressed by selective placement of the catalyst in the mold.
Online Learning of Part Deformation Models in Robotic Cleaning of Compliant Objects
Authors: Langsfeld Joshua D. , Kabir Ariyan M. , Kaipa Krishnanand N. , Gupta Satyandra K.
Published: September 2016

We present an approach to automatically learn a bimanual robotic cleaning task on compliant objects. One robot grasps the object, while the other robot cleans it. Given a part with unknown deformation characteristics, the system visually detects the regions to be cleaned, and generates plans for both the grasping and cleaning arms. As the system performs cleaning attempts and gains experience with multiple new parts, it learns models of the part deformation depending on the cleaning force and grasping parameters. A planner iteratively generates tool paths for both robots using the available knowledge to optimize the cleaning time, including (1) delays from regrasping a part to minimize deflection and (2) time taken for repeated cleaning attempts over regions that remained dirty. A nonparametric deflection model is learned separately for each part, with minimal assumptions of the material behavior. We demonstrate the approach on a system of two KUKA LWR iiwa robots and a set of thin planar parts. Results indicate that the system is effective at rapidly learning part deformation models to enable effective iterative cleaning performance.
Selective Laser Melting of Graphene Reinforced Inconel 718 Superalloy: Evaluation of Microstructure and Tensile Performance
Authors: Wang Yachao , Shi Jing , Lu Shiqiang , Wang Yun
Published: September 2016

Graphene nanoplatelets (GNPs) have many outstanding properties, such as high mechanical strengths, light weight, and high electric conductivity. These unique properties make it an ideal reinforcement used for metal matrix composite (MMCs). In the past few years, many studies have been performed to incorporate GNPs into metal matrix and investigate the properties of obtained metal matrix composites. Meanwhile, fabrication of MMCs through laser assisted additive manufacturing (LAAM) has attracted much attention in recent years due to the advantages of low waste, high precision, short production lead time, and high workpiece complexity capability. In this study, the two attractive features are combined to produce GNPs reinforced MMC using selective laser melting (SLM) process, one of the LAAM processes.

The target metal matrix material is Inconel 718, a nickel-based Ni-Cr-Fe austenitic superalloy that possesses excellent workability and mechanical performance and has wide applications in industries. Inconel 718 holds outstanding mechanical performance, corrosion, oxidation, and wear performance over a wide range of temperatures, making it an attractive superalloy used for high temperature service components. In the experiment, pure Inconel 718 and GNPs reinforced Inconel 718 composites with two levels of GNPs content (i.e., 0.25 and 1 wt.%) are obtained by SLM. Note that the SLM process, a novel powder mixture procedure is adopted to ensure the even dispersion of GNPs in the Inconel 718 powders. Room temperature tensile tests are conducted to evaluate the tensile properties. Scanning electron microscopy (SEM) observations are conducted to analyze the fracture surface of materials and to understand the reinforcing mechanism. It is found that fabrication of GNPs reinforced MMC using SLM is a viable approach. The obtained composite possesses dense microstructure and significantly enhanced tensile strength. The ultimate tensile strengths (UTS) are 997.8, 1296.3 and 1511.6 MPa, and the Young’s moduli are 475, 536, and 675 GPa, for 0 wt.% (pure Inconel 718), 0.25 wt.%, and 1 wt.% GNP additions, respectively. The bonding between GNPs and matrix material appears to be strong, and GNPs are well retained during the SLM process. The strengthening effect and mechanisms involved in the composites are discussed. Load transfer, thermal expansion coefficient mismatch, and dislocation hindering are believed to be the three main reinforcing mechanisms involved.

It should be noted that more work needs to be conducted in the future to obtain more comprehensive information regarding other static and dynamic properties, and the high temperature performances of the GNP reinforced MMCs produced by SLM. Process parameter optimization should also be investigated.
Forecast Method of Customer Needs Volatility to Personalized Product
Authors: Haijiang Liu , Kaixiang Xu , Zhenhua Pan
Published: September 2016

To capture and forecast the volatility of customer needs, this paper proposes a forecast method within the framework of QFD (Quality Function Deployment), based on CTS (compositional time series) and VAR model (vector auto-regression model). The CTS formed by customer needs importance rating sampling within a period of time are treated as the basis to predict the future customer needs. Firstly, the CTS are transformed from the simplex space to the real domain. Then, the VAR model is established based on the time series obtained in the real domain. This model is used to accurately forecast beyond the sample and the predictive result is transformed back to the simplex space to obtain the predictive customer needs importance rating time series. Based on the predictive customer needs importance rating, the design attributes predictive priorities are calculated, which can guide the resources allocation in the development of personalized product, to provide better personalized product that is more in line with future customer needs. The case shows that the proposed method is effective.
The Coupling Between Densification and Optical Heating in Intense Pulsed Light Sintering of Silver Nanoparticles
Authors: Bansal Shalu , Chang Chih-Hung , Malhotra Rajiv
Published: September 2016

Sintering of nanoparticles deposited onto rigid or flexible substrate is required for many devices that use continuous and patterned thin films. An emerging need in this area is to perform nanoparticle sintering under ambient conditions, at high speeds, and with throughput that is compatible with high speed nanoparticle deposition techniques. Intense Pulsed Light sintering (IPL) uses a high energy, broad area and broad spectrum beam of xenon lamp light to sinter metallic and non-metallic nanoparticles. The capability of IPL to meet the above needs has been demonstrated. This paper experimentally examines temperature evolution and densification during IPL. It is shown, for the first time, that temperature rise and densification in IPL are related to each other. A coupled optical-thermal-sintering model on the nanoscale is developed, to understand this phenomenon. This model is used to show that the change in nanoscale shape of the nanoparticle ensemble due to sintering, reduces the optically induced heating as the densification proceeds, which provides a better explanation of experimental observations as compared to current models of IPL. The implications of this new understanding on the performance of IPL are also discussed.
Ultrasonic Nanocrystal Surface Modification Assisted Nitriding: An Experimental Study
Authors: Zhao Jingyi , Ren Zhencheng , Liu Yang , Sang Xiahan , Hou Xiaoning , Wang G.-X. , Dong Yalin , Ye Chang
Published: September 2016

A powerful surface severe plastic deformation (SSPD) technique, ultrasonic nanocrystal surface modification (UNSM) has been used to treat pure iron to induce surface nanocrystallization. Transmission electron microscopy and surface profiler were used to study the microstructure and surface roughness after UNSM. Results indicate that the surface nanocrystallization with the controllable surface roughness was obtained. After that, gas nitriding of the nanocrystalline and microcrystalline iron was carried out and compared. X-ray diffraction, micro hardness testing and energy dispersive spectroscopy were applied to investigate the phase, micro hardness and distribution of nitrogen atoms in the iron sample after nitriding. It has been found that nitriding efficiency has been significantly improved in UNSM-processed samples than that in the non-processed samples as manifested by higher hardness and higher volume fraction of the nitride phase. With appropriate nanocrystallization, nitriding can occur efficiently at temperature as low as 300 °C.
Promoting Model-Based Definition to Establish a Complete Product Definition
Authors: Ruemler Shawn P. , Zimmerman Kyle E. , Hartman Nathan W. , Hedberg Thomas , Barnard Feeney Allison
Published: September 2016

The manufacturing industry is evolving and starting to use 3D models as the central knowledge artifact for product data and product definition, or what is known as Model-based Definition (MBD). The Model-based Enterprise (MBE) uses MBD as a way to transition away from using traditional paper-based drawings and documentation. As MBD grows in popularity, it is imperative to understand what information is needed in the transition from drawings to models so that models represent all the relevant information needed for processes to continue efficiently. Finding this information can help define what data is common amongst different models in different stages of the lifecycle, which could help establish a Common Information Model. The Common Information Model is a source that contains common information from domain specific elements amongst different aspects of the lifecycle. To help establish this Common Information Model, information about how models are used in industry within different workflows needs to be understood. To retrieve this information, a survey mechanism was administered to industry professionals from various sectors. Based on the results of the survey a Common Information Model could not be established. However, the results gave great insight that will help in further investigation of the Common Information Model.
Assembly Hierarchy Generation for Assembly System Design for a Product Family
Authors: Jiang Zhengqian , Wang Hui
Published: September 2016

Increased demand on product variety entails a flexible assembly system for product families which can be quickly configured and reconfigured in a responsive manner to deal with various product designs. Development of such a responsive assembly system requires an in-depth understanding of the impact of product family design on assembly system performance. In this paper, the linkage between the product family design and assembly systems is characterized by an assembly hierarchy model, which reflects a hierarchical relationship among all possible sub-assemblies and components, assembly tasks, and material flow among the tasks. Our prior research developed a recursive algorithm to generate all assembly hierarchy candidates for one single product based on its liaison graph without redundancy. These generated assembly hierarchies provide a structure to help efficiently explore optimal assembly system designs with reduced computational load. In this paper, the application of the assembly hierarchy generation algorithm will be extended to a product family by developing joint liaison graph model. Taking the advantage of the modular design of the product family, we proposed a concept of multi-level joint liaison graphs to overcome the computational challenge brought by assembly hierarchy generation for joint liaisons. Two case studies were conducted to demonstrate the algorithm.
Mechanical Ruling of Diffraction Grating: Part I — Aluminum Film Preparation and Characterization
Authors: Wang Qinghua , Zhang Baoqing , Shen Ninggang , Ding Hongtao
Published: September 2016

This is Part I of a two part series study on mechanical ruling of diffraction grating. Mechanical ruling is a major method for fabricating diffraction grating. In mechanical ruling, the first step is to prepare the Al film. High quality preparation technique is needed to satisfy the requirements of the thickness and the mechanical properties of the film. The purpose of this paper is to present a complete study on the preparation technique and mechanical properties of the Al film used for mechanical ruling of diffraction grating. XRD and SEM experiments and analysis were conducted to investigate the microstructure of the Al film and the mechanical properties of the Al film were measured using nanoindentation and scratch tests. The Al film exhibits favorable mechanical properties which will the key for the experimental and numerical simulation studies of mechanical ruling of diffraction grating.
Influence of Preheating Temperature on Mechanical Properties of Laser Cladding Layer
Authors: Jiang Jibin , Lian Guofu , Xu Mingsan , Li Chunyu , Chen Bingsan , Li Bingbing
Published: September 2016

Physical and chemical changes always occur in the process of laser cladding, and the cladding quality is directly affected by processing parameters. This paper mainly focused on effects of temperature field of preheating substrate on the cladding quality. Laser cladding process has the following experimental parameters: laser power, powder feeding rate and rotational speed. Three types of cladding powders were used: Ni60A, Cr12MoV and WC-Co. Experiments were conducted by using different substrate preheating temperatures and cladding materials, which affect the quality of cladding layers. Comparison and analysis of the three types of powders showed that under different preheating temperatures, the cladding layer is mainly affected by tensile stress. Besides that, the residual stress of cladding layer is always higher than that of heat affected zone and substrates.

The best preheating temperature to test the residual stress for three types of powders are: 600°C, 400°C and 300°C. For all three types of powders under different preheating temperatures, cladding layer and substrate have compact and uniform structures. However, when substrate is overheated the cracking will occur in the substrate. Under different preheating temperatures, the Vickers hardness is higher than that of heat affected zone and the substrate for all three materials. The preheating temperatures for getting the maximum hardness are respectively 300°C, 600°C and 400°C.
Roll-to-Roll Manufacturing System Modeling and Analysis by Stream of Variation Theory
Authors: Shui Huanyi , Jin Xiaoning , Ni Jun
Published: September 2016

A multistage system that consists of multiple stages for sequential operations to finish products is widely employed in modern manufacturing systems. Due to the characteristics of multistage systems, the product quality not only depends on operations in current stage but is also affected by operations in upstream stages. Most existing studies use Stream of Variation models to analyze error propagation and interactions among multiple stages in discrete manufacturing systems such as machining shops and assembly systems. In this paper, a multistage model based on the “Stream of Variation” concept is developed to investigate the tension propagation in a flexible material roll-to-roll manufacturing system. This modeling method uses a physical model coupled with a data-driven model to correlate the roller operation performance and product quality characteristics. Torque equilibrium analysis and Hooke’s law are employed for physical model and the censored regression model is used to explore unknown structures/parameters. A web unwinding process demonstrates the feasibility and prediction performance of the proposed model. The result shows that the proposed multistage model can serve as a virtual metrology method to increase system visibility, enhance health management capability and eventually improve product quality.
Cost Estimation Model for PAN Based Carbon Fiber Manufacturing Process
Authors: Gill Amaninder Singh , Visotsky Darian , Mears Laine , Summers Joshua D.
Published: September 2016

A polyacrilonitrile (PAN) based carbon fiber manufacturing cost estimation model driven by weight is presented in this study. One of the biggest limiting factors in the large scale use of carbon fiber (CF) in manufacturing is its high cost. The costs involved in manufacturing the carbon fiber have been formalized into a cost model in order to facilitate the understanding of these factors. This can play a key role in manufacturing CF in a cost effective method. This cost model accounts for the fixed and variable costs involved in all stages of manufacturing, in addition to accounting for price elasticity.
Estimation of Real-Time Active Maintenance Opportunity Windows in Manufacturing Systems With Bernoulli Machines
Authors: Gu Xi , Jin Xiaoning , Guo Weihong
Published: September 2016

Effective maintenance operations are essential to improve the competitiveness of manufacturing enterprises. However, the existing maintenance policies usually ignore the real-time dynamics of the system and cannot respond promptly to the demand changes in the market. This paper investigates the hidden opportunities that one machine can be stopped for maintenance during production time, while the throughput requirement in a specific horizon can still be satisfied. We define these time windows as active maintenance opportunity windows (AMOWs), and predict them based on the real-time operational data in manufacturing systems with different configurations and Bernoulli machines.
Direct Printing of Capacitive Touch Sensors on Flexible Substrates by Additive E-Jet Printing With Silver Nanoinks
Authors: Qin Hantang , Cai Yi , Dong Jingyan , Lee Yuan-Shin
Published: September 2016

In this paper, techniques of direct printing of capacitive touch sensors on flexible substrates are presented. Capacitive touch sensors were fabricated by using electrohydrodynamic inkjet (E-jet) printing onto flexible substrates. Touch pad sensors can be achieved with optimized design of silver nanoink tracks. An analytical model was developed to predict touch pad capacitance, and experiments were conducted to study the effects of sensor design (e.g. number of electrodes, electrode length, and electrode distance) on the capacitance of printed coplanar capacitance touch sensors. Details of the fabrication techniques were developed to enable rapid prototype flexible sensors with simple structure and good sensitivity. The presented techniques can be used for the on-demand fabrication of different conductive patterns for flexible electronics with high-resolution and good transparency.
A Comparative Analysis Between High Speed Dynamic and Traditional Pocketing Toolpaths in Precision Milling Machines
Authors: Minquiz Gustavo M. , Borja Vicente , López-Parra Marcelo , Dornfeld David , Flores Pablo
Published: September 2016

Different types of toolpaths have been extensively studied with regards to different factors such as energy consumption and tool wear. However, toolpaths have been introduced recently, where high speeds and dynamic movements are combined to provide higher performance. The aim of this paper is to compare a spiral toolpath strategy, which has been studied previously with good results in energy consumption, with a high speed dynamic toolpath strategy, which combines helical and dynamic movements, with regards to energy consumption, tool wear and carbon emissions. Several advantages are identified with a high speed dynamic toolpath strategy over the typical spiral toolpath strategy in terms of tool wear, energy consumption and carbon emissions. The results show that the high speed dynamic toolpath is a better alternative for different milling operations such as slotting, pocketing, and face milling.
Towards Improved Hybrid Joining of Aluminum Alloys to Carbon Fiber Composites With Friction Stir Welding
Authors: Franke Daniel J. , Morrow Justin D. , Duffie Neil A. , Zinn Michael , Pfefferkorn Frank E.
Published: September 2016

The current methods for welding aluminum alloys to carbon fiber composites rely heavily on the adhesive bond created when a melted polymer solidifies in contact with the aluminum surface. This bond may be improved by achieving mechanical interlocking of the carbon fibers and the aluminum alloy, so that load bearing fibers contribute to the bond strength. Friction Stir Welding (FSW) holds potential as a process to achieve such interlocking by locally heating and plasticizing the metal under significant load to cause infiltration of the metal into the carbon fiber weave. During preliminary investigations, AA6061-T6 was friction stir welded in contact with dry carbon fiber bundles, and the infiltration of aluminum into the fibers was measured. The results were compared to an accepted polymer infiltration model that was adapted for aluminum infiltration, giving promising initial agreement. This suggests that the plasticized aluminum in FSW can be treated as a fluid with an effective viscosity, and that well established polymer infiltration models can form the base of a metal composite FSW model.
Spontaneous Fabrication of Three Dimensional Multi-Scale Fractal Structures Using Hele Shaw Cell
Authors: Islam Tanveer ul , Gandhi Prasanna S.
Published: September 2016

Several bio-systems such as leaf veins, respiratory system, blood circulation, some plant xylem etc., involving multi-scale fractal topologies are being mimic for their inherent natural optimization. 3D fractal structures spanning multiple scales are difficult to fabricate. In this paper we demonstrate a new method to fabricate structures spanning meso and micro-scale in a relatively easy and inexpensive manner. A well known Saffman-Taylor instability is exploited for the same in a lifted Hele-Shaw cell. In this cell a thin layer of liquid is squeezed between two plates being lifted angularly leaving behind the fractal rearrangement of fluid which is proposed to be solidified later. We demonstrate and characterize fractal structures fabricated using two different fluids and corresponding methods of solidification. The first one is ceramic suspension in a photo-polymer and another is polystyrene solution with photo-polymerization and solvent vaporization as methods of solidification respectively. The fabrication process is completed in period of a few seconds.
A Critical Change Point Detection Method in Threaded Steel Pipe Connection Processes Using Two Stage Sequential Piecewise Linear Approach
Authors: Du Juan , Zhang Xi
Published: September 2016

Leak tightness is one of the key quality characteristics of oil pipelines. In pipe connection processes, this quality characteristic is mainly characterized by two critical interpretable change points in the torque signals collected by sensors mounted on the connection machine. However, because of various noises from the operation and measurement systems, latent process factors, such as mechanical return difference, assembling misalignment, and straightness of pipes, cause various nonlinear patterns to exist in the torque signals. Hence, precisely identifying the change points for automatic quality examination is still challenging. In this paper, a two-stage modeling framework is proposed to utilize sequential change point detection to precisely locate the two critical change points. A two-phase regression model based on the F maximum test is employed to detect all potential change points in the first stage. Subsequently, a two-step backward change point selection algorithm based on mechanical principles is implemented to select the critical change points in the second stage. Finally, the change point selection based on a three-phase regression model is developed. The efficacy of the proposed framework is validated by a case study on a real threaded steel pipe connection process.
Micro-Machining of Glass Using Electrochemical Discharge Assisted Cutting
Authors: Jiang Baoyang , Ni Jun
Published: September 2016

Glass is a hard-to-machine material with vast industrial application. Electrochemical discharge machining (ECDM) is a non-traditional machining technology that has shown potential for effective glass machining. However, ECDM has not been widely used in industry despite being studied for over a decade. Major challenges of ECDM include limited machinable depth and low material removal rate. In this paper, an innovative hybrid machining process combining ECDM and traditional cutting is presented, namely electrochemical discharge assisted cutting. The material removal rate of the hybrid ECDM process is significantly higher than conventional processes. Experimental results are presented to prove the feasibility and capability of the process. Discussion concentrates on the improvement of geometric accuracy and surface integrity through experimentation.
A Systematic Approach for Computer-Aided Gating-System Design for Die Casting Dies
Authors: Singh Ranjit , Kumar Rajesh , Madan Jatinder
Published: September 2016

Multi-gates are often used in the die-casting die design to provide proper feed of the molten metal to the cavity for obtaining a sound casting. Although a number of systems for design of gating-systems are available they do not help much to design multi-gates. A computer aided system for gating-system for die-casting die-design with multi-gates is proposed in this paper. The proposed system helps to generate parameters of the multi-cavity die taking into account a multitude of factors, such as part design, material properties, process data and die-casting machine information. The parameters so generated are applied on selected gating-system feature existing in the library to complete the design of gating-system. The system generated results for industrial case-study parts are in tandem with the industry practices. The proposed system would greatly help bridge the existing gaps between design and manufacturing for die-casting die-design.
Segmented Cutting Coefficient Based Chatter Modeling for High-Speed Micromilling of Ti6Al4V
Authors: Singh Kundan K. , Kartik V. , Singh Ramesh
Published: September 2016

Miniature components with complex shape can be created by micromilling with high surface accuracy. However, for difficult-to-machine materials, such as Ti-alloys, failure of low flexural stiffness micro-tools is a big limitation. High spindle speeds (20,000 to 100,000 rpm) can be used to reduce the undeformed chip thickness and the cutting forces and hence the catastrophic failure of the tool can be avoided. This reduced uncut chip thicknesses, in some cases lower than the cutting edge radius, can result in intermittent chip formation which can lead to dynamic variation in cutting forces. These dynamic force variations coupled with low flexural rigidity of micro end mill can render the process unstable. Consequently, accurate prediction of forces and stability is essential in high-speed micromilling. Most of the previous studies reported in the literature use constant cutting coefficients in the mechanistic cutting force model which does not yield accurate results. Recent work has shown significant improvement in the prediction of cutting forces with velocity-chip load dependent coefficients but a single function velocity-chip model fails to predict the forces accurately at very high speeds (>80,000 rpm). This inaccurate force prediction affects the predicted stability boundary at those speeds. Hence, this paper presents a segmented approach wherein a function is fit for a given range of speed to determine the chip load dependent cutting coefficients. The segmented velocity-chip load cutting coefficient improves the cutting force prediction at high speeds. R2 value is found to be improved significantly (>90% for tangential cutting coefficient) which yields the better forces prediction and hence more accurate stability boundary. This paper employs two degrees of freedom (2-DOF) model with forcing functions based on segmented velocity-chip load dependent cutting coefficients. Stability lobe diagram based on 2-DOF model has been created for different speed ranges using Nyquist stability criteria. Chatter frequency ranges between 1.003 to 1.15 times the experimentally determined first modal frequency. Chatter onset has been identified via a laser displacement sensor to experimentally validate the predicted stability lobe.
Scalable Manufacturing of Metal Nanoparticles by Thermal Fiber Drawing
Authors: Zhao Jingzhou , Javadi Abdolreza , Lin Ting-Chiang , Hwang Injoo , Yang Yingchao , Guan Zeyi , Li Xiaochun
Published: September 2016

Thermal fiber drawing has emerged as a novel process for the continuous manufacturing of semiconductor and polymer nanoparticles. Yet a scalable production of metal nanoparticles by thermal drawing is not reported due to the low viscosity and high surface tension of molten metals. Here we present a generic method for the scalable nanomanufacturing of metal nanoparticles via thermal drawing based on droplet break-up emulsification of immiscible glass/metal systems. We experimentally show the scalable manufacturing of metal Sn nanoparticles (<100 nm) in Polyethersulfone (PES) fibers as a model system. This process opens a new pathway for scalable manufacturing of most metal nanoparticles as well as composites with embedded metal nanoparticles, which may find exciting photonic, electrical, or energy applications.
The Current State of Sensing, Health Management, and Control for Small-to-Medium-Sized Manufacturers
Authors: Helu Moneer , Weiss Brian
Published: September 2016

The development of digital technologies for manufacturing has been challenged by the difficulty of navigating the breadth of new technologies available to industry. This difficulty is compounded by technologies developed without a good understanding of the capabilities and limitations of the manufacturing environment, especially within small-to-medium enterprises (SMEs). This paper describes industrial case studies conducted to identify the needs, priorities, and constraints of manufacturing SMEs in the areas of performance measurement, condition monitoring, diagnosis, and prognosis. These case studies focused on contract and original equipment manufacturers with less than 500 employees from several industrial sectors. Solution and equipment providers and National Institute of Standards and Technology (NIST) Hollings Manufacturing Extension Partnership (MEP) centers were also included. Each case study involved discussions with key shop-floor personnel as well as site visits with some participants. The case studies highlight SME’s strong need for access to appropriate data to better understand and plan manufacturing operations. They also help define industrially-relevant use cases in several areas of manufacturing operations, including scheduling support, maintenance planning, resource budgeting, and workforce augmentation.
Development of Foamed PES-Zeolite Mixed Matrix Membranes for PEM Fuel Cell Humidification
Authors: Borduin Russell , Li Wei
Published: September 2016

Polymer electrolyte membrane (PEM) fuel cell efficiency must be improved in order to become cost-competitive with fossil fuel based technologies. Approaches to increasing cost efficiency include raising fuel cell operating temperature, reducing component cost and properly controlling fuel cell humidification. We sought to fulfill all three requirements by developing a new low-cost, high-temperature humidification membrane material. Currently Nafion dominates the membrane humidifier market due to its excellent water transport characteristics, but its high price (∼$1000/m2) and low maximum operating temperature (<90°C) drive up fuel cell cost. We developed a competing PES-zeolite mixed matrix membrane (MMM) with a porous microstructure. Solvent casting was used to form the initial PES-zeolite films, followed by solid state foaming to alter the film morphology and create a porous structure. The effects of both zeolite weight loading and foaming duration on membrane permeability were investigated. Membrane measurement results show both foaming and increased zeolite weight loading enhance membrane water permeability close to levels seen in Nafion. Meanwhile, the membranes satisfies the Department of Energy (DOE) crossover gas requirement for humidification membrane materials.
Gaps Analysis of Integrating Product Design, Manufacturing, and Quality Data in the Supply Chain Using Model-Based Defintion
Authors: Trainer Asa , Hedberg Thomas , Barnard Feeney Allison , Fischer Kevin , Rosche Phil
Published: September 2016

Advances in information technology triggered a digital revolution that holds promise of reduced costs, improved productivity, and higher quality. To ride this wave of innovation, manufacturing enterprises are changing how product definitions are communicated — from paper to models. To achieve industry’s vision of the Model-Based Enterprise (MBE), the MBE strategy must include model-based data interoperability from design to manufacturing and quality in the supply chain. The Model-Based Definition (MBD) is created by the original equipment manufacturer (OEM) using Computer-Aided Design (CAD) tools. This information is then shared with the supplier so that they can manufacture and inspect the physical parts. Today, suppliers predominantly use Computer-Aided Manufacturing (CAM) and Coordinate Measuring Machine (CMM) models for these tasks. Traditionally, the OEM has provided design data to the supplier in the form of two-dimensional (2D) drawings, but may also include a three-dimensional (3D)-shape-geometry model, often in a standards-based format such as ISO 10303-203:2011 (STEP AP203). The supplier then creates the respective CAM and CMM models and machine programs to produce and inspect the parts. In the MBE vision for model-based data exchange, the CAD model must include product-and-manufacturing information (PMI) in addition to the shape geometry. Today’s CAD tools can generate models with embedded PMI. And, with the emergence of STEP AP242, a standards-based model with embedded PMI can now be shared downstream.

The on-going research detailed in this paper seeks to investigate three concepts. First, that the ability to utilize a STEP AP242 model with embedded PMI for CAD-to-CAM and CAD-to-CMM data exchange is possible and valuable to the overall goal of a more efficient process. Second, the research identifies gaps in tools, standards, and processes that inhibit industry’s ability to cost-effectively achieve model-based-data interoperability in the pursuit of the MBE vision. Finally, it also seeks to explore the interaction between CAD and CMM processes and determine if the concept of feedback from CAM and CMM back to CAD is feasible. The main goal of our study is to test the hypothesis that model-based-data interoperability from CAD-to-CAM and CAD-to-CMM is feasible through standards-based integration. This paper presents several barriers to model-based-data interoperability. Overall, the project team demonstrated the exchange of product definition data between CAD, CAM, and CMM systems using standards-based methods. While gaps in standards coverage were identified, the gaps should not stop industry’s progress toward MBE. The results of our study provide evidence in support of an open-standards method to model-based-data interoperability, which would provide maximum value and impact to industry.
Characterization of Forces in High-Speed Bone Cutting and Grinding for Haptics Rendering
Authors: Danda Avinash , Kao Yi Tang , Kuttolamadom Mathew A. , Tai Bruce L.
Published: September 2016

This study characterizes the forces in high-speed bone cutting and grinding for the use of haptic devices in surgical simulations. Unrealistic force feedback due to the lack of vibrational features is one of the most common drawbacks. Generally, the force profile can be decomposed to a mean force and a vibrational force magnitude. These forces are experimentally measured under various motions, including feed rate and tool orientation, to mimic manual operations and to understand the effects of these parameters. Change in feed rate was found to be insignificant in the overall force feedback, while the change in tool orientation showed statistically significant effects. The grinding burr and cutting burr also exhibited different forces under an identical condition. The explanation for the behavior of the forces based on the cutting and grinding conditions is discussed along with the results.
Modeling of Brittle and Ductile Materials Drilling Using Smoothed-Particle Hydrodynamics
Authors: Tajdari Mahsa , Tai Bruce L.
Published: September 2016

The objective of this study is to investigate smoothed particle hydrodynamics (SPH) method in simulating drilling process of both brittle and ductile materials. Drilling simulation is commonly performed by finite element method (FEM); however, it is challenging when applied to small debris generated by brittle materials or special cutting tools, due to the inability to capture small chip interactions. SPH was originally developed for flow analysis but has been recently used in cutting research. In this study, SPH is compared with FEM by four case studies. The results show that SPH can simulate ductile drilling, but the chip formation and forces are not as reasonable as FEM. On the other hand, SPH can capture small fragmented debris in brittle material drilling, which cannot be done by FEM with an equivalent mesh size. SPH method is also found to be affected by the distance between the particles (element size in FEM) and numerical errors on the free surfaces, both of which require further investigation beyond this paper.
Modeling Evolution of Microstructures Beneath Topographically Textured Surfaces Produced Using Shear Based Material Removal
Authors: Basu Saurabh , Wang Zhiyu , Saldana Christopher
Published: September 2016

Tool chatter is envisaged as a technique to create undulations on fabricated biomedical components. Herein, a-priori designed topographies were fabricated using modulate assisted machining of oxygen free high conductivity copper. Subsequently, underpinnings of microstructure evolution in this machining process were characterized using electron back scattered diffraction based orientation imaging microscopy. These underpinnings were related to the unsteady mechanical states present during modulated assisted machining, this numerically modeled using data obtained from simpler machining configurations. In this manner, relationships between final microstructural states and the underlying mechanics were found. Finally, these results were discussed in the context of unsteady mechanics present during tool chatter, it was shown that statistically predictable microstructural outcomes result during tool chatter.
Effect of Applied Electricity on Springback During Bending and Flattening of 304/316 Stainless Steel, Titanium AMS-T-9046 and Magnesium AZ31B
Authors: Niebauer Jacklyn , Grimm Tyler , Shaffer Derek , Sweeney Ian , Ragai Ihab , Roth John T.
Published: September 2016

One of the major issues with forming sheet metal is the tendency for parts to spring back towards their original shape when the applied loading is released. Springback is a form of geometric inaccuracy and is the result of residual stresses, which are created as the part deforms. As a result, forming intricate parts require specialized equipment and calculations to compensate for springback. Transportation industries that rely on forming high strength parts currently use complicated machinery that takes up time and energy to meet specifications. This research investigates the effects of electrically assisted manufacturing (EAM), a process in which electrical current is applied while a material is being manufactured, on springback. Bending and flattening testing will be performed on 4 metals: stainless steel 304 and 316, ASM-T-9046 titanium, and AZ31B magnesium. Additional testing will be performed on stainless steel, observing the effect of changing thicknesses, pulse durations, and current densities on springback. It was observed that an increase in pulse durations results in decreased springback for all the materials. Applying electricity to decrease springback was more effective for bending than flattening procedures in stainless steel and titanium, though it was equally effective for magnesium. For the additional testing on stainless steel, a change in thickness affected results when comparing it to current density, but not when observing similar applied current.
Laser Cladding of Alumina Material Coating: Effects on Deposition Quality
Authors: Li Yuzhou , Cong Weilong , Ning Fuda , Huang Rongxia
Published: September 2016

Alumina ceramic is a high performance engineering material with excellent properties, including high melting point, high hardness and brittle nature make the alumina ceramic difficult to machine and needing high cost by using conventional manufacturing methods. Coating is an important method for alumina fabrication. The excellent properties of coatings can be used for special surface protection and ceramic parts repairing. Comparing with other coating methods, laser cladding method has many good properties to overcome the drawbacks. The reported investigations on laser cladding provide little information about alumina materials for ceramic coating. In this paper, effects of different input variables of laser cladding of alumina materials for ceramic coating were studied. And this paper for the first time reported the relationship between the properties (including surface roughness, flatness and powder efficiency) and input variables such as laser power, powder feeding rate and laser head moving rate. The obtained results will be helpful to establish efficient and effective processes for ceramics coating.
Stress and Deformation Evaluations of Scanning Strategy Effect in Selective Laser Melting
Authors: Cheng Bo , Shrestha Subin , Chou Y. Kevin
Published: September 2016

Selective laser melting (SLM) is one of the Additive manufacturing (AM) processes that can build physical part in an added material method from digital data. In such a process, computer designed part model will be decomposed into hundreds of thousands of layers. The layered information is then transferred to SLM equipment and the part is built in a layer by layer fashion. Each powder layer will be scanned and melted in the required region by a high energy laser beam in a given scanning pattern so as to form a desired geometry. Finally, fully functional parts can be produced by repeatedly powder deposition, melting and solidification process. This process offers numerous advantages such as tooling-free productions and design freedom in geometry. In addition, SLM process is quite suitable for complicated parts such as customer designed medical implants and internal channels which are difficult to manufacture by conventional methods such as casting and machining. However, the localized heating and cooling process can lead to defects such as high residual stress, part distortion or delamination failure in SLM fabricated parts. These potential defects may impede the wide application of this technology. It is known that the laser beam scanning path will affect the thermomechanical behaviors of the build part, and thus, altering the scanning pattern may be a feasible strategy to reduce residual stresses and deformations by influencing the heat intensity input distribution. In this study, a 3D sequentially coupled finite element method (FEM) model, incorporating a volumetric moving Gaussian heat source, powder as well as solid material temperature dependent properties and layer addition features, was developed to study the complex thermomechanical process of SLM. The model was applied to evaluate six different scanning strategies effect on part temperature, stress and deformation. The major results have been summarized as follows. (1) Among all cases tested, the out-in scanning pattern has the maximum stresses along the X and Y directions; while the 45 degree inclined scanning may reduce residual stresses in both directions. (2) Large directional stress difference can be caused by back and forth line scanning strategy while minor directional stress difference is observed for other tested cases. (3) X and Y directional stress concentration is shown around the edge of deposited layers and the interface between deposited layers and substrate for all cases. (4) The 45 degree inclined scanning case has the smallest build direction deformation while the in-out scanning case has the largest deformation among the tested cases.
Residual Stresses in Flow Drill Screwdriving of Aluminum Alloy Sheets
Authors: Milner Justin L. , Gnäupel-Herold Thomas , Skovron Jamie D.
Published: September 2016

With an increase in fuel economy standards and the need for reducing emissions set for the automotive sector, has resulted in the increased demand for lightweight vehicles. It is well know that the single heaviest component of a passenger vehicle is the body structure, thus has the greatest potential for significantly reducing the vehicles mass. Therefore, transitioning from steel-based bodies to ones composed of lightweight materials, such as: aluminum, magnesium and advanced high strength steels are of great interest. However, with the introduction of these new materials comes with a new means of joining, where conventional methods do not work. Therefore, this work examines a novel joining technique, flow drill screwdriving which is a thermo-mechanical process for joining aluminum and dissimilar materials. The focus of this work is to examine the residual stress distribution in a joint, because mechanical behavior and joint quality are greatly affected by the residual stress. Neutron diffraction was used for the determination of the residual stress in two samples processed with low and high fastener force. The high penetration depth of neutron radiation allows for the determination of triaxial residual stress states inside the material without destruction of the sample. It was found that the stress field around the joint location is primarily in tension, which is problematic if external forces are applied near the joint. Therefore, additional stress measurements were conducted under applied load through a lap shear test. Two load levels were applied to determine the effects on stress concentrations around the proximity of the joint.