bluuebunny/crossref_metadata_2025 huggingface dataset:
Feature Selection for Helicopter Swashplate Bearing Fault Diagnosis
Authors: Wang Yong , Li Lin
Published: July 2017

This paper provides a case study of diagnosing helicopter swashplate ball bearing faults using vibration signals. We develop and apply feature extraction and selection techniques in the time, frequency, and joint time-frequency domains to differentiate six types of swashplate bearing conditions: low-time, to-be-overhauled, corroded, cage-popping, spalled, and case-overlapping. With proper selection of the features, it is shown that even the simple k-nearest neighbor (k-NN) algorithm is able to correctly identify these six types of conditions on the tested data. The developed method is useful for helicopter swashplate condition monitoring and maintenance scheduling. It is also helpful for testing the manufactured swashplate ball bearings for quality control purposes.
Software Defined Manufacturing Extends Cloud-Based Control
Authors: Lechler Armin , Verl Alexander
Published: July 2017

Nowadays, the key goal in manufacturing is being very efficient within changing markets and under turbulent conditions. Therefore, production plants with their machines logistics and all the other involved components have to be adaptable to changing conditions.

For this reason, reconfigurable manufacturing systems are needed, which allow a fast adaption to new requirements of the product to be manufactured. Today, reconfiguration in manufacturing is mostly limited due to missing reconfigurability of the control software in combination with the underlying hardware. The coupling is that strong that in manufacturing control software is always bound to special hardware. Until now, flexibility is only possible by changing application or part programs that are interpreted by a fixed control kernel. The adaption of any core functionality is impossible, and any other changes require high manual effort for redesigning software systems and parametrizing their functionalities. For better adaptability in manufacturing this coupling has to be dissolved.

Other disciplines and industries have similar requirements like the information and communication technology (ICT). In the area of ICT, there are more and more concepts of Software Defined Anything (SDX) like Software Defined Networking (SDN) or Software Defined Radio (SDR). Flexible, adaptive and really reconfigurable manufacturing should be improved by a new concept of Software Defined Manufacturing (SDM). SDM allows freely defined functionalities within the physical limitations of the mechanical and electrical components of a machine. But current manufacturing equipment with its control architecture does not offer the technical basis for such a concept.

Existing concepts of cloud-based control architectures show indeed a virtualization of the control algorithms. Due to the fact that the software is running remotely, the software is decoupled from its hardware. However, the local control algorithms with hard real-time requirements still have a very strong coupling with the hardware. The local control software could not be defined freely according to the requirements of the product to be manufactured. In this paper, a new control architecture for manufacturing that combines cloud-based control as a service (CaaS) and Software Defined Manufacturing is presented. As a result, an architecture of an operating system for manufacturing equipment is shown, which is freely programmable. This paper deals with Software Defined Manufacturing for local control software, communication and cloud-based control systems. SDM allows defining the behavior of the entire manufacturing process based on design description of a product to be manufactured. In addition, methods are described, which allow the automatic configuration and optimization of such an architecture by using simulation technics and collected process data.
Development of Post-Processing System for Three Types of Five-Axis Machine Tools Based on Solid Model
Authors: Li J. , Song Yangpeng , Liu Ye
Published: July 2017

Although machine control data can be obtained by means of converting cutter location (CL) data comprised of the tool tip coordinate and the tool axis orientation vector in the workpiece coordinate frame with postprocessor, it’s uncertain whether they can be used for 5-axis machining. Owing to the fact that most postprocessors focus on the method to derive solutions for the equations of NC data by the form-shaping function matrix and the inverse kinematics model without taking the manufacturing scene into consideration, this study has presented a new post-processing system to generate and optimize NC data more effectively by correcting and selecting optimum solution intelligently for machining based on the solid model of machine tool in simulation environment. In general, the post-processing system consists of user interface layer, data access layer and data processing layer to give expression to the characteristics of universality, practicality and adaptability. User interface layer is mainly about loading the machine model and setting the relevant parameters. Data access layer includes model library of generalized five-axis machine tool configurations, rules library of cutter location data and NC data. Data processing layer is the major research in the paper, which illustrates how to correct the inverse solutions set and select the optimization solution for actual machining. The visual interface for post-processing system written by C++ was successfully applied in the experiment on a five-axis machine tool with a C-axis behind a B-axis rotary table, which demonstrated the effectiveness of the proposed post-processing methodology in the field of manufacturing.
Controlling Topography of Machined Surface for Adhesive-Sealing
Authors: Liu Shun , Jin Sun , Zhang Xueping , Wang Lixin , Mei Benfu , Hu Bin
Published: July 2017

Adhesive is widely used in engine, airplane and other industry parts to bond and seal machined joint surfaces. Adhesive performance is important and mechanically complex, closely related to the adhesive material property, bonding process and topography of machined surfaces. The effects of material properties, bonding process, and the geometry and dimensions of adhesive layer on adhesive performance have been well studied in adhesive research field. However, the effect of the topography of machined surface on sealing performance was somehow neglected in literature. On the other hand, the texture of machined surface, especially at micro-level of surface roughness, usually used as the objective to determine process parameters in machining and also regarded as indicators of machining productivity, has been systemically and sufficiently studied. However sealing performance has not been widely investigated to relate to topography of machined surface generated from machining operation. Actually, the surface topography plays an important role in the both fields as an index for machining process and also a factor for functional performance. Desired surface should be determined firstly and then machining parameters are designed properly to achieve the desired surface, in order to improve the functional behavior such as the applied adhesive sealing performance of machined components. This research has objectives: 1) the desired surface topography is determined based on the relationship between machining operation and surface texture; 2) The effects of machined surface topography on the reliability of adhesive joint surfaces are analytically investigated. Thus, the research provides a systematic thinking for the selection of surface topography and parameters of face milling operation to improve the performance of adhesive bonding and sealing for its industry implementation.
Design and Fabrication of Electrostatic Microcolumn With Varying Apertures in Massively Parallel Electron Beam Lithography
Authors: Du Zhidong , Wen Ye , Pan Liang
Published: July 2017

Massively parallel electron beam lithography may be an alternative manufacturing method in semiconductor industry if the issues of the multi electron beam source are addressed. The microcolumns are suitable for the massively parallel electron beam lithography because of their compactness and the ability to achieve high spatial resolution. A new design with varying apertures for our recent nanoscale photoemission source is presented here. Given the easiness of the fabrication of the microcolumn, we optimized the parameters of the design and found that the resolution can be improved by changing the ratio between the diameters of the focus and extractor electrodes.
Phase Transformations During High-Speed, High-Temperature Scratching of Silicon
Authors: Alreja Chirag , Subbiah Sathyan
Published: July 2017

Higher temperature assisted processing of silicon, such as in heat-assisted diamond turning, is often being considered to improve surface integrity. At higher temperatures and under mechanical loading and unloading, caused by the moving tool, silicon deforms plastically often in association with occurrence of phase transformations. This paper investigates such phase transformations in rotational scratching of single crystal (100) p-type silicon with a conical diamond tool under various furnace-controlled temperatures ranging from room temperature to 500 °C and at scratching speeds comparable to that used in the diamond turning process (1 m/s). Phase transformation study, using Raman spectroscopy, at various crystal orientations, show differences in phases formed at various temperatures when compared to that reported in indentation. The tendency to form phases is compared between scratched and diamond turned surfaces at room temperature, and also with that reported at low scratching speeds in the literature. Analysis of depths of the scratched groove indicates that that at temperatures beyond a certain threshold, plastic deformation and significant elastic recovery may be causing shallow grooves. This study is expected to help tune heat-assisted diamond turning conditions to improve surface formation.
Assessment of Optical Performance of Aspheric Germanium Lens Manufactured Using Single Point Diamond Turning
Authors: Yadav Shivam Pradeep , Shaikh Haseen , Pawade Raju Shrihari
Published: July 2017

Manufacturing of aspheric profile of lens at nanometric level is difficult but the measurement and evaluation of metrology parameters is still a bigger challenge. For successful results of the lens systems, precise and defect free lenses are required. The manufacturing conditions have direct effect on the metrological parameters. For appropriate evaluation of metrology parameters, proper interpretation of aspheric surface parameters must be known. . In this study, the mechanical parameters, such as radius of curvature, slope error, tilt, centre thickness, and sag value of lens, were measured by using contact type form talysurf, non-contact type fizeau interferometers, and other instruments. The experimental results reveal that an increase in the spherical aberration is caused by increasing the lens thickness beyond 4.995mm or by increasing the radius of curvature beyond −13.8396mm or by increasing the aspheric higher order coefficients. Also its dependencies on the diameter of least confusion is studied.
The Pressure Straightening Technology of Linear Guide Rails Using Dual Indenter-Dual Clamp System
Authors: Zhang Yongquan , Lu Hong , Fan Wei , Wang Shaojun , Wei Qinyu , Ling He
Published: July 2017

To improve the compressive capacity and straightening efficiency of straightening process, the stroke-deflection model (SDM) using dual indenter and dual clamp system (DIDCS) for linear guide rails is developed in this paper. The DIDCS is actually simplified as a symmetrically supported beam with two symmetrical concentrated forces on the top surface of workpiece, so the straightening process is regarded as pure bending process. To explore the deflection variation during the whole process with DIDCS, the curvature-deflection model (CDM) considering the span control of dual indenter and dual clamp is firstly analyzed based on elastic-plastic deformation theory and small deformation principle. The geometrical features and material properties of linear guide rails, which are the main factors influencing bending characteristics, are then mathematically modeled for the further analysis of stress and strain distributions in straightening process. Besides, to obtain the actual bending moment model (BMM) of different model parameters, the distribution regulations of elastic and plastic regions are analyzed followed by pure bending assumptions. The bending rebound model (BRM) is established with bending moment, geometrical features and material properties, and the SDM is finally calculated by initial deflection, rebound deflection and span parameters of the DIDCS. On basis of the DIDCS, the straightening process is simulated with the established finite element analysis model (FEM) to demonstrate the longitudinal stress distribution and the reflection of different straightening stages. The proposed SDM is also experimentally validated on the ROSE-JZ50 straightening machine with different materials.
An Effective Spiral Trajectory Generation Approach for the Turning of Piston Skirt With Middle-Bulged Varying Ellipse
Authors: Lu Hong , Su Xiangang , Zhang Xinbao , Zhang Yongquan , Fan Wei , Wang Shaojun
Published: July 2017

Given the chord length of equal angle isn’t equal on elliptical section of piston skirt with middle-bulged varying ellipse (PSMVE), a larger theoretical processing error will inevitably be introduced with the interpolation algorithm of equal angle for PSMVE. To improve the manufacturing precision of PSMVE, a novel interpolation algorithm of equal-length-chord and spiral-line (IAES) and a method of tool radius compensation are presented based on symbolic computation. Firstly, a three-dimensional model of PSMVE is generated through the symbolic computation method, meanwhile, the coordinate values of arbitrary cutter-contact point can be expressed accurately. Secondly, the turning spiral trajectory is generated via updated cutter-contact point which can be searched from the obtained cutter-contact point with equal length chord. Besides, this paper proposes a method of tool radius compensation and obtains the cutter location points through appropriate transformation of coordinates. Last, some simulation, which mainly includes the establishment of 3D model, the generation of spiral trajectory with equal-length-chord, the transformation between cutter-contact point and cutter-location points, is carried out. In addition, this paper takes CNC turning center (System: SINUMERIK 802C) as an example to complete the processing of PSMVE. Experiment results verify that the machining method is appropriate for PSMVE.
Design for Additive Manufacturing in the Cloud Platform
Authors: Wang Yuanbin , Blache Robert , Xu Xun
Published: July 2017

Additive manufacturing (AM) has experienced a phenomenal expansion in recent years and new technologies and materials rapidly emerge in the market. Design for Additive Manufacturing (DfAM) becomes more and more important to take full advantage of the capabilities provided by AM. However, most people still have limited knowledge to make informed decisions in the design stage. Therefore, an interactive DfAM system in the cloud platform is proposed to enable people sharing the knowledge in this field and guide the designers to utilize AM efficiently. There are two major modules in the system, decision support module and knowledge management module. A case study is presented to illustrate how this system can help the designers understand the capabilities of AM processes and make rational decisions.
Chatter Detection in Milling Process Based on Time-Frequency Analysis
Authors: Liu Meng-Kun , Tran Quang M. , Qui Yi-Wen , Chung Chun-Hui
Published: July 2017

Chatter identification is necessary in order to achieve stable machining conditions. However, the linear approximation in regenerative chatter vibration is problematic because of the rich nonlinear characteristics in machining. In this study, a novel method to detect chatter is proposed. Firstly, measured cutting force signals are decomposed into a set of intrinsic mode functions by using ensemble empirical mode decomposition. Hilbert transform is following to extract the instantaneous frequency. Fast Fourier transform is also utilized for each intrinsic mode function to determine the intrinsic mode function that contains rich chatter. Finally, the standard deviation and energy ratio in frequency domain of intrinsic mode functions are found as simply dimensionless chatter indicators. The effectively proposed approach is validated by analyzing the machined surface topography and also compared to the stability lobe diagram.
Multi-Tenant Access Control Model for Cloud Manufacturing
Authors: Chen Qianwen , Zhou Zude , Zhang Xiaomei , Jiang Xuemei
Published: July 2017

Cloud manufacturing is a new service-oriented networked manufacturing mode based on the concept of “Manufacture as a Service” and achieves the sharing of manufacturing resources and manufacturing capacity. Multi-tenancy technology can improve utilization efficiency of manufacturing resources and ensure information security among tenants, enabling users to share the cloud manufacturing resources better. To execute this new mode, isolation access and on-demand services are indispensable. However, the traditional access control model cannot satisfy the demands of multi-tenant environment on cloud manufacturing platform. To solve the demands in such an environment, a model named Multi-Tenant Access Control Model for Cloud Manufacturing (CM-MTAC) is proposed. Based on cloud manufacturing architecture, we build a hierarchical cloud manufacturing access control architecture combining multi-tenancy. Considering the demands under this condition, the elements of cloud manufacturing access control model and the relationships between them are redefined by extending the ABAC model. Then multi-tenancy authorization framework is proposed and XACML language is used to describe the policy to provide our model with on-demand service, isolation access and inter-tenant collaboration. Finally, we develop this model into the cloud manufacturing monitoring platform. Results show that our model, compared with traditional models, has a better performance of on-demand service, isolation access and inter-tenant cooperation under the environment of cloud manufacturing.
Induction Hardening Process With Preheat to Eliminate Cracking and Improve Quality of a Large Part With Various Wall Thickness
Authors: Li Zhichao (Charlie) , Ferguson B. Lynn
Published: July 2017

During an induction hardening process, the electromagnetic field generated by the inductor creates eddy currents that heat a surface layer of the part, followed by spray quenching to convert the austenitized layer to martensite. The critical process parameters include the power and frequency of the inductor, the heating time, the quench delay time, the quench rate, and the quench time, etc. These parameters may significantly affect case depth, hardness, distortion, residual stresses, and cracking possibility. Compared to a traditional hardening process, induction hardening has the advantages of low energy consumption, better process consistency, clean environment, low distortion and formation of beneficial residual stresses. However, the temperature gradient in the part during induction hardening is steep due to the faster heating rate of the surface and the aggressive spray quench rate, which leads to a high phase transformation gradient and high magnitude of internal stresses. Quench cracks and high magnitude of residual stresses are more common in induction hardened parts than those of conventional quench hardening processes. In this study, a scanning induction hardening process of a large part made of AISI 4340 with varying wall thickness is modeled using DANTE. The modeling results have successfully shown the cause of cracking. Based on the modeling results, a preheat method is proposed prior to induction heating to reduce the in-process stresses and eliminate the cracking possibility. This process modification not only reduces the magnitude of the in-process tensile stress, but also converts the surface residual stresses from tension to compression at the critical inner corner of the part, which improves the service life of the part. The modified process has been successfully validated by modeling and implemented in the heat treating plant.
A Case Study Investigating the Environmental Impact of Pelleting in Cellulosic Biofuel Manufacturing
Authors: Kesharwani Rajkamal , Islam Md Monirul , Song Xiaoxu , Sun Zeyi , Zhang Meng , Dagli Cihan
Published: July 2017

Cellulosic biofuel manufacturing consists of two major processes, biomass feedstock preprocessing and bioconversion. Traditionally, these two processes are conducted in different locations in practice and transportation is required to connect the two processes. Pelleting in preprocessing can help reduce the size and increase the density of biomass so that the transportation and handling can be more efficient. However, pelleting is also considered an energy-intensive process that consumes a large amount of energy, which leads to considerable greenhouse gas emissions. Due to such an environmental and energy related concern, the use of pelleting process in real industry is still in doubt regarding its performance of environmental sustainability although it has been extensively studied in laboratory scale. In this paper, we analyze both positive and negative impacts of pelleting in biofuel manufacturing regarding GHG emissions. A numerical case study focusing on the transportation is conducted to examine such impacts through the comparison between the scenarios with and without pelleting process to estimate the net emission due to the pelleting process.
A Data-Driven Approach to Detect Mechanical Faults in Wind Turbine Gearbox
Authors: Li Ruoyu , Sun Zeyi
Published: July 2017

Online condition monitoring systems play an important role in preventing catastrophic failure, reducing maintenance costs, and improving the system reliability. In this paper, wind turbine gearbox mechanical fault detection system is developed. An adaptive filtering technique is applied to separate the impulsive components from the periodic components of the vibration signals. Then different features of the periodic components and impulsive components are extracted. An extreme learning machine based classifier is designed and trained by using the features extracted from simulated vibration data of wind turbine gearbox. Simulated vibration signals of wind turbines gearbox are used to demonstrate the effectiveness of the presented methodology.
Study on the Generation and Redistribution Mechanism of Residual Stress in Bilateral Rolling Correction Process for Thin-Walled Parts
Authors: Lu Laixiao , Sun Jie , Guo Kai , Li Jianfeng
Published: July 2017

The distortion and dimensional instability are the main problems in the machining of thin-walled parts with high-strength aluminum alloys. To ensure the accuracy of aircraft assembly, distortion correction process is essential. Bilateral rolling process has been widely used to correct the distorted parts in the aerospace industries due to the introduction of proper plastic deformation and residual stresses. However, the generation and redistribution mechanism of residual stresses in bilateral rolling correction process remains unclear. This internal mechanism was investigated by finite element method (FEM) in this paper. First, FE models were verified by experiments in terms of residual stresses and strain. Then, simulation results (e.g. plastic strain, true strain and part distortion) were extracted for further analysis. It was shown that the residual stresses are produced in the compatibility process of plastic and elastic strain, and a large plastic deformation can lead to a high amplitude residual stresses. Besides, the binding force from the surrounding materials also results in higher strain gradient and amplitude of residual stresses. Although part distortion has little effect on the limit value of residual stresses, it greatly influences the redistribution of the residual stresses.
Static Recrystallization Behavior of a Nitrogen Controlled Z2CN19-10 Austenitic Stainless Steel
Authors: Luo Min , Xu Chun , Zhou Bing , Guo Yan-hui , Li Rong-bin
Published: July 2017

In order to increase the hot workability and provide proper hot forming parameters for nitrogen controlled Z2CN19-10 austenitic stainless steel, the static recrystallization behavior was investigated by double-pass hot compression tests in the temperature range of 950–1100°C, initial grain size of 72μm–152μm, and the strain rates of 0.01, 0.1, 1, and 5 s−1. The tests were conducted with inter-pass times varying between 1 and 100 s after achieving a pass strain of 0.05, 0.1, 0.15 and 0.2 in the first pass on a Gleeble-1500 thermo-mechanical simulator. The static recrystallization fraction has been predicted by the 2 % offset stress method and verified by metallographic observations. The metallographic results indicate the crystallized grains generate at the cross of the prior austenite grain boundary and grow up. Also the kinetics of static recrystallization behavior for Z2CN19-10 steel are proposed. Experimental results show that the volume fraction of static recrystallization increases with the increase of deformation temperature, strain rates, pass strain and interval time, while it decreases with the increase of initial grain size. According to the present experimental results, the activation energy (Q) and Avrami exponent (n) was determined as 199.02kJ/mol and 0.69. The established equations can give a reasonable estimate of the static recrystallization behavior for Z2CN19-10 steel.
Machining Operation Process Planning System Considering User Strategies and Intentions
Authors: Hirai Taishi , Nishida Isamu , Sato Ryuta , Shirase Keiichi
Published: July 2017

In this study, we propose a new process planning system for machining operations, one which considers user strategies and intentions for such operations.

In previous process planning systems, the machining sequence is calculated geometrically, based on the Total Removal Volume (TRV) and the machining primitive region split from TRV. However, it remains difficult to determine the best machining sequence from among the large number of machining sequences calculated. Also, previous process planning systems do not consider user strategies and intentions in determining the appropriate machining sequence.

Our new approach stores geometrical properties of the machining primitives when the user selects a machining sequence. Using these stored geometrical properties, the appropriate machining sequence can be automatically selected. User strategies and intentions are thus considered in determining a machining sequence based on learned geometrical properties.

A case study was conducted to show the effectiveness of our proposed process planning approach. In the case study, user-specific machining sequences were automatically determined for various users, based on the relation among the geometrical properties of the machining primitives and the individual user’s strategies and intentions.
Pricing Method for Service-Oriented Manufacturing With Support Vector Machine
Authors: Meng Qiunan , Lou Jian , Xu Xun , Yu Shiqiang
Published: July 2017

To evaluate the effects of customers’ participation levels in various business activities on pricing in service-oriented manufacturing, the indices of pricing are proposed through extracting the influential factors in the four stages (i.e., design, manufacturing, production and services) from the whole value chain to comprehensively reflect customers’ demands. A new pricing model based on these indices is formulated by Support Vector Machine (SVM). It can predict a more accurate product price regarding the products’ similarity by the values of the influential factors that are determined in terms of business activities participated by customers. Finally, a case study from a molding company in China is conducted to verify the effectiveness of this pricing methodology. The results indicate that the model by SVM fares better in comparison with that by Back Propagation Neural Networks in small scale samples, especially in the performances of generalization and robustness. The outcomes also testify that this price prediction methodology can increase the accuracy of a product’s price as well as the customer’s satisfaction.
Effects of Surface Roughness on Bonding Behavior of Cold Spray Ti6Al4V Coatings
Authors: Sun Wen , Tan Adrian Wei Yee , Marinescu Iulian , Liu Erjia
Published: July 2017

In this study, a penitential additive manufacturing method - cold spray was used to deposit Ti6Al4V powders onto Ti6Al4V substrates with different surface roughness by using a high pressure cold spray system. The coating quality was good with limited porosity and without phase transition. Interface bonding behavior between coating and substrate was studied, which indicated that smoother substrate surface would increase the bonding strength. Bending test showed that all the coated samples started to delaminate before substrate failure and smoother surface samples could resist higher stress than the rougher surface samples.
Integrative Technology and Inspection Planning: A Case Study in Medical Industry
Authors: Klocke Fritz , Müller Johannes , Mattfeld Patrick , Kukulies Jan , Schmitt Robert H.
Published: July 2017

In most trendsetting industries like the aerospace, automotive and medical industry functionally critical parts are of highest importance. Due to strict legal requirements regarding the securing of the functionality of high-risk parts, both production costs and quality costs contribute significantly to the manufacturing costs. Thus, both types of costs have to be taken into consideration during the stage of technology planning. Due to the high variety of potential interactions between individual component properties as well as between component properties and manufacturing processes, the analysis of the influence of the manufacturing history on an efficient design of inspection processes and inspection strategies is extremely complex. Furthermore, the effects of inspection strategies and quality costs on the planning of manufacturing process sequences cannot be modeled to date. As a consequence, manufacturing and inspection processes are designed separately and thus a high cost reduction potential remains untapped.

In this paper a new approach for an integrative technology and inspection planning is presented and applied to a case study in medical industry. At first, existing approaches with regard to technology and inspection planning are reviewed. After a definition of relevant terms the case study is introduced. Following, an approach for an integrative technology and inspection planning is presented and applied to the case study. In the presented approach the complex causalities between technology planning, manufacturing history and inspection planning are considered to enable a cost-effective production process and inspection sequence design.
Vibration Control of Computer Numerically Controlled Lathe With CFRP Pipe Frame
Authors: Yamada Honoka , Sawatani Kazuki , Morimoto Yoshitaka , Suzuki Naohiko , Kaneko Yoshiyuki
Published: July 2017

A new computer numerically controlled lathe containing a carbon fiber-reinforced plastic pipe frame was developed in this study. The pipe frame structure is lightweight and allows the machine size and stiffness to be adjusted by varying the parameters of the frame structure. Furthermore, using carbon fiber-reinforced plastic instead of steel improves the heat deformation properties of the frame.

When employing a pipe frame structure for machine tools, structural vibration can be problematic. In particular, the relative vibration between the tool and the workpiece must be suppressed to improve the accuracy of the machined surface. To achieve this vibration suppression, an actuator driven by piezoelectric elements was installed in the frame of the developed CNC lathe structure to counteract the vibration at specific modes by applying active vibration control. As a result of using the proposed vibration control method, the vibration amplitude was reduced by up to 88.6% compared with that without control. Additionally, the circularity of workpiece was improved by 27%.
Fabrication of Micro-Channels in PMMA by Tip-Based Microfabrication Technique: Depth and Friction Analysis
Authors: Stan Felicia , Fetecau Catalin , Stanciu Nicoleta V.
Published: July 2017

In this paper, millimeter-scale straight parallel micro-channels were fabricated in PMMA (Polymethyl-methacrylate) using the tip-based micro-fabrication method. The dimensional characteristics (channel width, channel depth and pile-up height) of micro-channels were evaluated and the effects of normal load and speed on the micro-channel geometry and friction were examined. A logarithmic relationship between the normal load and micro-channel depth was identified. The experimental results indicate that the selection of the normal load is critical to achieve a desired micro-channel geometry using a single pass scratching. To machine a micro-channel with a finite depth in PMMA, the normal load must be higher than 4.5 N. Within the range of the tested normal loads, about 70% of the channel height was elastically recovered after a single pass, and pile-ups as high as 50–60% of the depth were observed along the micro-channel sides.
Remaining Useful Life Estimation Based on a Segmental Hidden Markov Model With Continuous Observations
Authors: Chen Zhen , Xia Tangbin , Pan Ershun
Published: July 2017

In this paper, a segmental hidden Markov model (SHMM) with continuous observations, is developed to tackle the problem of remaining useful life (RUL) estimation. The proposed approach has the advantage of predicting the RUL and detecting the degradation states simultaneously. As the observation space is discretized into N segments corresponding to N hidden states, the explicit relationship between actual degradation paths and the hidden states can be depicted. The continuous observations are fitted by Gaussian, Gamma and Lognormal distribution, respectively. To select a more suitable distribution, model validation metrics are employed for evaluating the goodness-of-fit of the available models to the observed data. The unknown parameters of the SHMM can be estimated by the maximum likelihood method with the complete data. Then a recursive method is used for RUL estimation. Finally, an illustrate case is analyzed to demonstrate the accuracy and efficiency of the proposed method. The result also suggests that SHMM with observation probability distribution which is closer to the real data behavior may be more suitable for the prediction of RUL.
An Investigation of Electroplastic Drilling of Mild Steel
Authors: Ruszkiewicz Brandt J. , Akhavan Niaki Farbod , Mears Laine , Gendreau Elizabeth
Published: July 2017

Increasing governmental fuel economy requirements drives automakers to increase the fuel economy of their fleets. One of the methods for improving fuel economy is lightweighting vehicles through the use of materials with high strength to weight ratios. Some of these new metals entering the automotive sector are difficult to machine and cause drastically reduced tool life and increase machining cost. It has been shown that electricity has the ability to reduce cutting force during orthogonal cutting and turning. In this research, a design of experiments study on an electrically assisted drilling operation is conducted to determine the impact and interaction between the following input parameters: applied electric current, feedrate, spindle speed, and number of holes cut. These variables used to determine impact and interaction on the following output variables: flank wear, axial cutting force, and temperature evolution. A 2D finite volume method model is used to predict drilling temperature during the process, and is used to aid in predicting axial force. It is found that electric current can reduce cutting force by 10% for 1008 steel at the cost of increased temperature, however, arcing at initial contact causes increased tool wear at higher current inputs.
Surface Grinding of Optical BK7/K9 Glass Using Rotary Ultrasonic Machining: An Experimental Study
Authors: Hu Yingbin , Wang Hui , Ning Fuda , Cong Weilong , Li Yuzhou
Published: July 2017

BK7/K9 glass is regarded as a difficult-to-machine material due to its high hardness and high brittleness properties as well as high tool wear rate during machining. Facing to these challenges, an efficient and effective rotary ultrasonic machining (RUM) process, consisting of grinding process and ultrasonic machining process, was provided to process BK7/K9 glass. In this investigation, the effects of ultrasonic power on cutting forces, torque, and edge chipping of surface grinding in RUM of BK7/K9 glass were studied. Results showed that, by introducing ultrasonic vibration to surface grinding process, both cutting forces in feeding direction and in axial direction as well as torque values were reduced. The higher the ultrasonic power was, the lower the forces and torque values would be. Edge chipping, which was detrimental to the qualities of machined slots and would cause high machining cost, was significant reduced with the help of ultrasonic vibration.
Control of Pressing Force in Magnetic Abrasive Finishing Using Permanent Magnet End-Mill Tool
Authors: Ma Lei , Hirogaki Toshiki , Aoyama Eiichi , Wu Wei , Furuki Tatsuya
Published: July 2017

The magnetic abrasive finishing (MAF) process is well known because of its high efficiency in yielding a mirror gloss finish zone. Clarification of the high efficiency machining mechanism has indicated that this high efficiency is obtained by iron particle cutting and the simultaneous polishing of alumina abrasives. This process yields unevenness, which is often evident on the workpiece surface. In a previous report, we compared magnetic polishing brushes consisting of iron powder paste (commercial paste) or steel balls (uniform size), and found that a large variation was generated when the magnetic polishing brush approached the workpiece surface in both cases. In this paper, we make slight changes to the steel-ball shape, obtaining saddle and barrel-shaped iron particles via stamping processing. The aim is to observe the control factor of the pressing force for these three different iron particle shapes and for different particle numbers, using a force sensor and a high-speed camera. The relationship between the iron particle shape, the iron particle number and the pressing force control is also explored in an attempt to discuss the mechanism behind the iron particle shape effect on the frictional force generation between the iron particles. It is found that the force variation can be reduced by adjusting the particle shape and number, which effectively reduces the damage caused when the brush approaches the workpiece surface.
Investigation of the Cleaning and Welding Steps From the Friction Element Welding Process
Authors: Skovron Jamie D. , Ruszkiewicz Brandt J. , Mears Laine , Abke Tim , Varma Ankit , Li Yuxin , Choi Hongseok , Zhao Xin
Published: July 2017

The requirement of increased fuel economy standards has forced automakers to incorporate multi-materials into their current steel dominant vehicles in order to lightweight their fleets. Technologies such as Self Piercing Rivets and Flow Drill Screws are currently implemented for joining aluminum to high-strength steels but only one-technology is viable for joining aluminum to ultra-high-strength steels without pre-holes, namely Friction Element Welding. This study is aimed at investigating how variations in the cleaning and welding steps of the Friction Element Welding process influence joint quality. A design of experiment was conducted to understand the influence of key process parameters (endload, spindle RPM, and relative distance) during these steps on the pre-defined joint quality metrics of head height, weld zone diameter, under-head fill area, temperature, and microhardness. It is found that cleaning step parameters have the greatest influence on process time and energy consumption, while welding step parameters greatly influence maximum torque on the element, head height, and underhead fill, with both cleaning force and weld force influencing weld diameter, all parameters influence temperature.
Assessing the Geometric Integrity of Additive Manufactured Parts From Point Cloud Data Using Spectral Graph Theoretic Sparse Representation-Based Classification
Authors: Tootooni M. Samie , Dsouza Ashley , Donovan Ryan , Rao Prahalad K. , Kong Zhenyu (James) , Borgesen Peter
Published: July 2017

This work proposes a novel approach for geometric integrity assessment of additive manufactured (AM, 3D printed) components, exemplified by acrylonitrile butadiene styrene (ABS) polymer parts made using fused filament fabrication (FFF) process. The following two research questions are addressed in this paper: (1) what is the effect of FFF process parameters, specifically, infill percentage (If) and extrusion temperature (Te) on geometric integrity of ABS parts?; and (2) what approach is required to differentiate AM parts with respect to their geometric integrity based on sparse sampling from a large (∼ 2 million data points) laser-scanned point cloud dataset? To answer the first question, ABS parts are produced by varying two FFF parameters, namely, infill percentage (If) and extrusion temperature (Te) through design of experiments. The part geometric integrity is assessed with respect to key geometric dimensioning and tolerancing (GD&T) features, such as flatness, circularity, cylindricity, root mean square deviation, and in-tolerance percentage. These GD&T parameters are obtained by laser scanning of the FFF parts. Concurrently, coordinate measurements of the part geometry in the form of 3D point cloud data is also acquired. Through response surface statistical analysis of this experimental data it was found that discrimination of geometric integrity between FFF parts based on GD&T parameters and process inputs alone was unsatisfactory (regression R2 < 50%). This directly motivates the second question. Accordingly, a data-driven analytical approach is proposed to classify the geometric integrity of FFF parts using minimal number (< 2% of total) of laser-scanned 3D point cloud data. The approach uses spectral graph theoretic Laplacian eigenvalues extracted from the 3D point cloud data in conjunction with a modeling framework called sparse representation to classify FFF part quality contingent on the geometric integrity. The practical outcome of this work is a method that can quickly classify the part geometric integrity with minimal point cloud data and high classification fidelity (F-score > 95%), which bypasses tedious coordinate measurement.
Multi-Objective Build Orientation Optimization for Powder Bed Fusion by Laser
Authors: Brika Salah Eddine , Mezzetta Justin , Brochu Mathieu , Zhao Yaoyao Fiona
Published: July 2017

This paper proposes an integrated approach to determine optimal build orientation for Powder bed fusion by laser (PBF-L), by simultaneously optimizing mechanical properties, surface roughness, the amount of support structure and build time-cost. Experimental data analysis has been used to establish the objective functions for different mechanical properties and surface roughness. Geometry analysis of the part has been used to estimate the needed support structure and thus evaluate the build time and cost. Normalized weights are assigned to different objectives depending on their relative importance allowing solving the multi-objective optimization problem using a genetic optimization algorithm. A study case is presented to demonstrate the capabilities of the developed system. The major achievements of this work are the consideration of multiple objectives, the establishment of objective function considering different load direction and heat treatments. A user-friendly graphical user interface was developed allowing to control different optimization process factors and providing different visualization and evaluation tools.
Impact of Non-Isothermal Warm Rolling on Microstructure, Texture and Mechanical Properties
Authors: Xu Chun , An Xing-zhou , Rao Xiao-hua , Li Ya-nan
Published: July 2017

To study the influence of non-isothermal deformation on microstructure, texture and mechanical properties, the CP Ti sheets were rolled to approximately 10% reduction per pass under a pair of rolls with different surface temperatures (i.e. non-isothermal rolled). The progress of recrystallization was enhanced with the increase of the difference in surface temperature between upper and lower rolls. When CP Ti sheets were non-isothermally rolled under the upper and lower rolls with surface temperatures of 210 and 120 °C, respectively, complete recrystallization occurred. Under such circumstances, it was found that the microstructure consists of equiaxed grains with the average size of 13μm and with mainly high-angle boundaries. Pyramidal  slip was the dominant deformation mechanism, and the elongation at room temperature was three times of that in the initial state. However, CP Ti sheets were rolled under a pair of roll with the same surface temperatures of 120 or 210 °C (i.e. isothermal rolled), recrystallization did not occur, and the microstructure, texture and mechanical properties of CP Ti isothermal rolling sheets were similar to those of conventional hot rolled CP Ti sheets.
Investigation of the Effects of Microgrooved Cutting Tool in High Speed Machining of AISI 1045 Steel
Authors: Chen Xingbang , Duong Nick H. , Ma J. , Lei Shuting
Published: July 2017

In this paper, numerical investigation of the effects of microgroove textured cutting tools in high speed machining of AISI 1045 is conducted using Finite Element Method (FEM). Microgrooves are designed and fabricated on the rake face of cemented carbide (WC/Co) cutting inserts. The effects of microgroove width, edge distance (the distance from cutting edge to the first microgroove), and microgroove depth are examined and assessed in terms of main cutting force, thrust force, and tool-chip contact length. It is found that microgrooved cutting tools generate lower cutting force and consequently lower the energy necessary for machining. This research provides insightful guidance for optimizing tool life and reducing energy consumption in high-speed machining of AISI 1045 steel.
Electrically Assisted Friction Stir Spot Welding of Aluminum Alloy to Advanced High Strength Steel
Authors: Chen Kai , Liu Xun , Ni Jun
Published: July 2017

This paper studies an electrically assisted friction stir spot welding (FSSW) process for joining aluminum alloy 6061-T6 to TRIP 780 steel. The electrical current shows to reduce the axial plunge force and assist the material flow of the aluminum matrix during the welding process. When electrical pulses and direct current (DC) with the same energy input are applied, the results show insignificant differences. Bulk material flow can be observed in the weld cross sections. A more uniform hook is generated at the Fe/Al interface after applying the current. Besides, the diffusion of aluminum atoms into the steel matrix is enhanced. Regarding the weld quality, electrically assisted FSSW improves the joint lap shear strength when compared with regular FSSW process.