bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary Study on Effects of the Process Parameters on Mechanical Properties in Liquid Holographic Volumetric Additive Manufacturing Process
Authors: James Sagil , Shivakumar Thilakraj 
Published: November 2019

Abstract
The momentum of the additive manufacturing research is on a spurt. Additive manufacturing, also known as 3D printing process has been attracting the attention of the manufacturing community worldwide over the past decade. The 3D printing technology promises significant advances and applications in the area of automobiles, electronics, and medical devices and so on. However, this technology currently suffers from several limitations including large time consumption, need for support structures and limited range of material selection. This prevents its application in mass production. Holographic 3D printing, also referred to as (volumetric additive manufacturing) process is a very recent technique which uses multiple light beams intensified to form a build volume. A photosensitive liquid resin is solidified using the principle of constructive interference. The single light beam is not enough to produce the required intensity to cure the resin. While the combined interference could generate the required energy. The resulting part is printed in a fraction of seconds at once in contrast with the traditional 3D printing technology. This research studies the feasibility of a novel holographic volumetric additive manufacturing with an ultraviolet source of 365 nm as the primary source of energy. This propels the polymeric photochemical reaction between the monomer molecules. Also, experiments are conducted, incorporating various viscosity levels of the photopolymer material to suppress the oxygen dissolution. At the same time to observe the rate of curing of the photopolymer material. Finally, the mechanical properties of the build volume are analyzed.
Effect of Beam Oscillations on Formation of Defects in Electron Beam Welding of Copper Plate
Authors: Jaypuria Sanjib , Chakrabarti Debalay , Pratihar D. K. , Jha M. N. 
Published: November 2019

Abstract
In the present study, electron beam welding bead-on-plate of electrolytic pitched copper (ETP-Cu) plate was carried out to study the behavior of different defects formed in the weld by varying the beam oscillation amplitudes. The defects like spattering, spiking and porosity were considered in this study. Spattering and spiking phenomena were determined with visual inspection and image analysis software, respectively. Porosity measurement was conducted with X-ray tomography. Spattering was found to decrease with the oscillation amplitude up to the optimized value and then, it showed an increasing effect with it. Spatters in the weld also contributed to the pore formation in the weld by the inside pores available in it. Spiking was found to be more dynamic, and not directly related to the oscillation amplitude. But, in general, it was increasing with the increase of amplitude. Spiking was found to have a linear relationship with mean diameter of pores, which implied that a weld with the sharper spikes was more prone to large size root pores in the weld. Mean diameter and volume fraction of the pores were tending to increase with oscillation amplitude; however, there were discontinuities in the trend at the optimized amplitude value. An optimized value of oscillation amplitude was found to be useful for suppressing these defects in the weld. However, a random oscillation amplitude could be more detrimental to the quality of the weld joint.
Friction Surfacing Using Consumable Tools: A Review
Authors: Seidi Ebrahim , Miller Scott F. 
Published: November 2019

Abstract
The friction surfacing technique is a new variation of friction stir welding process for modification of the surface properties of the substrate. There is a growing body of literature dealing with friction surfacing by consumable tool. This is a metallic deposition technique in which a rotating consumable tool deposits material onto a solid substrate. Friction surfacing has many applications in welding, coating, repair of defective components, hard surfacing and corrosion protection. This process does not generate high temperatures; therefore this technique is a suitable coating method capable of joining low melting point alloys. This review paper studies the basic principles and the use of friction surfacing as well as a survey of the latest researches and applications with emphasis on superficial and microstructural characterization, tensile, bending, effects of the different process factors such as axial force, rotation and travel speed, material deposition rate, energy consumption and different tool types. This review shows there are a few investigations dealing with novel tool/workpiece configurations for adding material for purposes other than coating, such as keyhole filling or dissimilar material joining. Also, the possible future directions for development and application of this technique are presented.
A Vision-Based Framework for Enhanced Quality Control in a Smart Manufacturing System
Authors: Yang Zixuan , Teng Huaiyuan , Goldhawk Jeremy , Kovalenko Ilya , Balta Efe C. , Lopez Felipe , Tilbury Dawn , Barton Kira 
Published: November 2019

Abstract
Dimensional metrology is an integral part of quality control in manufacturing systems. Most existing manufacturing systems utilize contact-based metrology, which is time consuming and not flexible to design changes. There have been recent applications of computer vision for performing dimensional metrology in manufacturing systems. Existing computer vision metrology techniques need repeated calibration of the system and are not utilized with data analysis methods to improve decision making. In this work, we propose a robust non-contact computer vision metrology pipeline integrated with Computer Aided Design (CAD) that has the capacity to enable control of smart manufacturing systems. The pipeline uses CAD data to extract nominal dimensions and tolerances. The dimensions are compared to the measured ones, computed using camera images and computer vision algorithms. A quality check module evaluates if the measurements are within admissible bounds and informs a central controller. If a part does not meet a tolerance, the central controller changes a program running on a specific machine to ensure that parts meet the necessary specifications. Results from an implementation of the proposed pipeline on a manufacturing research testbed are given at the end.
Binder Jetting Additive Manufacturing of Ceramics: Comparison of Flowability and Sinterability Between Raw and Granulated Powders
Authors: Du Wenchao , Miao Guanxiong , Liu Lianlian , Pei Zhijian , Ma Chao 
Published: November 2019

Abstract
The objective of this study is to compare three different feedstock powders for the binder jetting process by characterizing their flowability and sinterability. Binder jetting additive manufacturing is a promising technology for fabricating ceramic parts with complex or customized geometries. Granulation is a promising material preparation method due to the potential high sinterability and flowability of the produced powder. However, no study has been made to systematically compare raw and granulated powders in terms of their flowing and sintering behaviors. This paper aims at filling this knowledge gap. Two raw powders (i.e., fine raw powder of 300 nm and coarse raw powder of 70 μm) and one granulated powder from spray freeze drying were compared. Different flowability metrics, including volumetric flow rate, mass flow rate, Hausner ratio, Carr index, and repose angle were measured. Different sinterability metrics, including sintered bulk density, volume shrinkage, and densification ratio were compared for all three powders. Results show that granulated powder achieved comparably high flowability to that of the coarse raw powder and also comparably high sinterability to that of the fine raw powder. Moreover, suitable metrics for the characterization of the sinterability and flowability for these three powders are recommended. This study suggests spray freeze drying produces high-quality feedstock powder for binder jetting process.
Graphene Synthesis on Ultrathin Metal Catalyst Films
Authors: Zhang Kaihao , Tawfick Sameh 
Published: November 2019

Abstract
Graphene synthesis on ultra-thin catalysts can allow the use of graphene-coated metal films in electronic applications. Graphene coated thin films are expected to offer superior mechanical performance owing to the strength of graphene. However, several factors need to be considered to assure the stability of thin films at the high temperatures required for graphene synthesis. In this work, we present a systematic framework for the selection of thin films (&lt; 1 micron thickness) to be used as catalyst for graphene synthesis. We present our progress towards the rapid synthesis of graphene at 1100°C in less than two minutes, thus avoiding solid state dewetting. The quality of the graphene is assessed by Scanning Electron Microscopy, Raman spectroscopy and indentation. It is shown that these films exhibit higher stiffness and resistance to crack propagation.
Determining Feasible Robot Placements in Robotic Cells for Composite Prepreg Sheet Layup
Authors: Malhan Rishi K. , Kabir Ariyan M. , Shah Brual , Centea Timotei , Gupta Satyandra K. 
Published: November 2019

Abstract
High-performance composites are widely used in industry because of specific mechanical properties and lightweighting opportunities. Current automation solutions to manufacturing components from prepreg (pre-impregnated precursor material) sheets are limited. Our previous work has demonstrated the technical feasibility of a robotic cell to automate the sheet layup process. Many decisions are required for the cell to function correctly, and the time necessary to make these decisions must be reduced to utilize the cell effectively. Robot placement with respect to the mold is a significant and complex decision problem. Ensuring that robots can collaborate effectively requires addressing multiple constraints related to the robot workspace, singularity, and velocities. Solving this problem requires developing computationally efficient algorithms to find feasible robot placements in the cell. We describe an approach based on successive solution refinement strategy to identify a cell design that satisfies all constraints related to robot placement.
Error Propagation in Digital Additive Remanufacturing Process Planning
Authors: Alkhateeb Mojahed , Rickli Jeremy L. , Christoforou Nicholas J. 
Published: November 2019

Abstract
A point cloud is a digital representation of a part that consists of a set of data points in space. Typically point clouds are produced by 3D scanners that hover above a part and records points in a large number that represent the external surface of a part. Additive remanufacturing offers a sustainable solution to end-of-use (EoU) core disposal and recovery and requires quantification of part damage or wear that requires reprocessing. This paper proposes an error propagation approach that models the interaction of each step of the additive remanufacturing process. This proposed model is formulated, and the results of the errors generated from the parameters of the scanner and point cloud smoothing are presented. Smoothing is an important step to reduce the noises generated from scanning, knowing the right smoothing factor is important since over smoothing results in dimensional inaccuracies and errors, especially in cores with smaller degrees of damage. It is important to know the error generated from scanning and point cloud smoothing to compensate in the following steps and generate appropriate material deposition paths. Inaccuracies in the 3D model renders can impact the remainder of the additive remanufacturing accuracy, especially because there are multiple steps in the process. Sources of error from smoothing, meshing, slicing, and material deposition are proposed in the error propagation model for additive remanufacturing. Results of efforts to quantify the scanning and smoothing steps within this model are presented.
An Experimental Study of Modulation-Assisted Turning of Ti6Al4V
Authors: Sandoval Juan , Nguyen Dinh , Kwon Patrick , Guo Yang 
Published: November 2019

Abstract
This paper presents an experimental study of modulation-assisted turning of Ti6Al4V. A piezo-actuated turning tool post has been designed and implemented on a CNC toolroom lathe to enable modulation-assisted turning process. Displacement and force measurements were performed to characterize the modulation turning process. Tool wear tests on conventional turning and modulation-assisted turning of Ti6Al4V with uncoated carbide tools were conducted for three different lubrication conditions, including dry, minimum quantity lubrication (MQL), and nano-platelet enhanced MQL (n-MQL). The tool wear study shows that modulation-assisted turning can reduce crater wear but increase the flank wear of the uncoated carbide tool. The cause leading to different performances of modulation-assisted turning on tool wear is discussed.
Rotary Ultrasonic Machining of CFRP Composites: Effects of Carbon Fiber Reinforcement Structure
Authors: Zhang Dongzhe , Wang Hui , Hu Yingbin , Chen Xiaoxu , Cong Weilong , Burks Anthony R. 
Published: November 2019

Abstract
Carbon fiber reinforced plastic (CFRP) composites have been widely used in many applications due to their superior properties of high strength-weight ratio, high stiffness, and high wear resistance. For assembly purposes, hole making is necessary for different applications of CFRP composites. Rotary ultrasonic machining (RUM) has been proposed and investigated for hole making of CFRP composites. Studies on the effects of machining variables, tool variables, workpiece orientation, and cooling conditions on output variables in RUM of CFRP composites have been investigated. The carbon fiber reinforcement structures of CFRP composites also affect the machining performances and part’s quality. However, there is no reported investigation on studying carbon fiber reinforcement structures’ influences in RUM of CFRP composites. Experiments were conducted for this paper to investigate the effects of carbon fiber reinforcement structure on cutting force, torque, and surface roughness. Three major conclusions can be drawn from the results of this experimental investigation. First, CFRP composites with unidirectional structure led to the smallest cutting force and torque, followed by CFRP composites with plain woven structure and twill woven structure. Second, the surface roughness on CFRP composites with plain woven structure was the smallest, followed by the CFRP composites with unidirectional structure and twill woven structure. In addition, CFRP composites with different reinforcement structures have the same tendencies of output variables with different machining variables.
Dimensional Accuracy in PolyJet Printing: A Literature Review
Authors: Thakare Ketan , Wei Xingjian , Pei Zhijian 
Published: November 2019

Abstract
PolyJet printing process is one of the additive manufacturing methods to print parts with high dimensional accuracy. To date, dimensional accuracies of such process have been investigated by a number of studies. This review will summarize those studies, and identify current trends. With respect to methods of measurements used in the reported studies, it is noted that no special preference is given to use of any method. In addition, the effects of four control variables of PolyJet process: part orientation, layer thickness, surface finish type and materials, on dimensional accuracy are noted based on the results of reported studies. There is consistency in results in studies considering control variables of layer thickness, surface finish type and materials. However, the results are inconsistent in studies considering part orientation.
Effect of Tool Condition on Cutting Mechanism in Micromilling
Authors: Varghese Alwin , Kulkarni Vinay , Joshi Suhas S. 
Published: November 2019

Abstract
Cutting mechanism in micromilling is governed by the tool condition along with the machining parameters and workpiece material properties. A rapid tool wear in micromilling often deteriorates the surface quality, which could be due to the occurrence of plowing. The effects of tool condition on the transition in cutting mechanisms from shearing to plowing have not been adequately addressed in micro milling. In this work, we attempt to correlate cutting mechanism with tool conditions, so that their influence on force and surface profiles are investigated. Micro milling experiments are performed to investigate these correlations. A fluctuation parameter has been defined to quantify the fluctuation in force signal. It is evident that as the feed varies from 0.2 μm/teeth to 5 μm/teeth, the fluctuation reduces and similar fluctuations are reflected on the generated surface also. The surfaces corresponding to lower force fluctuations has an Ra value less than 350 nm. As cutting edge radius increases, surface finish decreases. However, with chipping, new sharper cutting edges are formed which may improve the surface finish locally but contribute to the overall variation in the surface profiles.
Simulating the Sequential Honing Process of Engine Cylinder Bore by Modeling Abrasives in Honing Stone
Authors: Zhou Zaoyang , Zhang Xueping , Lv Kunlun , Wu Jun , Yao Zhenqiang , Xi Lifeng 
Published: November 2019

Abstract
Sequential honing process is usually implemented in engine cylinder bore processing to obtain the cross-hatched surface texture with excellent function to balance lubricant storage capacities and supporting performance. Many researches have devoted to correlating honed surface quality of cylinder bore with honing process parameters by means of experiments or simulations. Quite a few efforts have addressed the effect of sequential multiple steps on the surface texture in the honing of engine cylinder bore. However, these researches cannot provide an explicit and analytical methodology to predict honed surface texture efficiently and accurately. This paper presents an analytical and explicit methodology to incorporate a proposed microscale abrasive model into the analytical simulation process of sequential honing. The proposed abrasive model synthetically considers the shape, size, posture, and position of abrasives randomly distributed in honing stone, which is incorporated into honing head motions in terms of rotation, oscillation and feeding. The kinematics of honing head is calculated by space-time discretization to capture the interaction between honing stones and cylinder bore surface. The above procedure acts as each single step for the sequential honing processes. This study investigates the sequential honing of two stages including semi-finish honing and plateau honing at different feeding speeds by applying the abrasive model with different abrasive sizes. The formation of cross-hatched surface texture was successfully achieved sequentially by semi-finish honing and plateaus honing. Then the Abbott-Firestone Curve of the honed surface can be obtained to analyze the influences of abrasive size and honing time of two stages on the surface roughness. Correctness of surface roughness predicted by the model is verified by comparing with a group of experiment measurements in terms of Abbott-Firestone Curve. Most errors of all the predicted Rk roughness family roughness parameters in the two honing stages are less than 15%. Based on the model, simulations are done to analyze the influences of abrasive size and honing duration time of two stages on the surface roughness. The result shows that the larger abrasive used in finish honing leads to the decrease of the material portions Mr1, Mr2 and the increase of the reduced valley depth Rvk. The longer plateau honing duration time is preferred to produce the larger Mr1, Mr2 and the smaller Rvk.
Prediction of Mechanical Properties of Direct Metal Laser Sintered 15-5PH Steel Parts Using Bayesian Inference: A Preliminary Study
Authors: Qattawi Ala , Ulutan Durul , Alafaghani Ala’aldin 
Published: November 2019

Abstract
Direct Metal Laser Sintering (DMLS) is an additive manufacturing process where metal parts are created layer by layer. Mechanical properties of the final product can vary significantly based on processing parameters. In traditional processes, such effects of processing parameters on mechanical properties are well-established. However, additive manufacturing methods are relatively new, which means there is less consensus, if at all, on how processing parameters affect mechanical properties of the final product. This study is a preliminary effort toward understanding the effects of processing parameters on mechanical properties of the metal. Processing parameters studied were the fabrication direction and temperature. Mechanical properties that were studied were the yield and tensile strength of the built material. 15-5PH stainless steel parts were DMLS fabricated with varying temperatures and directions for this purpose and their mechanical properties were measured. Then, a statistical approach was followed in order to generate a probabilistic prediction model. In this approach, Gibbs sampling was used to randomly sample from population of coefficients, Metropolis algorithm was used for decision-making purposes based on performance of different coefficient sets, and an empirical model was hypothesized. Then, the model was trained using a training dataset, and the cloud of coefficient sets for the hypothesized equation were obtained. Using these coefficient sets, the probable normal distribution of other test conditions was predicted and verified using testing data. It was shown that all measurements were well within the confidence interval of predictions, with a maximum difference of 4% between mean predictions and measurements. It was also observed that with a coefficient of variation smaller than 18%, spread of predictions was low enough to suggest that predictions were precise as well as their accuracy.
Test–Retest Reliability of Student-Administered Health-Related Fitness Tests in School Settings
Authors: O’Keeffe Brendan T. , Donnelly Alan E. , MacDonncha Ciaran 
Published: November 2019

Purpose: To examine the test–retest reliability of student-administered (SA) health-related fitness tests in school settings and to compare indices of reliability with those taken by trained research-assistants. Methods: Participants (n = 86; age: 13.43 [0.33] y) were divided into 2 groups, SA (n = 45, girls = 26) or research-assistant administered (RA; n = 41, girls = 21). The SA group had their measures taken by 8 students (age: 15.59 [0.56] y, girls = 4), and the RA group had their measures taken by 8 research-assistants (age: 21.21 [1.38], girls = 5). Tests were administered twice by both groups, 1 week apart. Tests included body mass index, handgrip strength, standing broad jump, isometric plank hold, 90° push-up, 4 × 10-m shuttle run, back-saver sit and reach, and blood pressure. Results: Intraclass correlation coefficients for SA (≥.797) and RA (≥.866) groups were high, and the observed systematic error (Bland–Altman plot) between test 1 and test 2 was close to 0 for all tests. The coefficient of variation was less than 10% for all tests in the SA group, aside from the 90° push-up (24.3%). The SA group had a marginally lower combined mean coefficient of variation across all tests (6.5%) in comparison with the RA group (6.8%). Conclusion: This study demonstrates that, following familiarization training, SA health-related fitness tests in school-based physical education programs can be considered reliable.