bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remaining Useful Life Prediction Based on Spindle Load and Cutting Process Parameters in Machining
Authors: Krishna Ankur , Muhammed Bilal 
Published: January 2020

Abstract
Tool wear increases machining resistance, part dimensional inaccuracy and machining vibration. Tool wear monitoring and Remaining Useful Life (RUL) prediction of the tool during machining operation will assist a machine operator to provide tool wear compensation at the right time and plan the tool change activity. These aspects become significantly important for economical and quality production. This work focuses on a physics and data-based approach for monitoring cutting tool wear state and Remaining Useful Life (RUL) during a machining operation by adapting a well-known empirical wear-rate equation. The constants in the model are estimated based on machine heuristics which depends on the tool-machine-workpiece combination. The proposed model takes real-time spindle power and machining process parameters as inputs, which are obtained directly through querying the CNC controller. Therefore, it does not require the mounting of any external sensors on the CNC machine tool. Hence, the proposed method is a more economical and convenient way to predict tool wear and RUL in a machining shop floor. The model is validated from experimental data and it can capture the progression of tool wear and RUL of the tool at any point of time during a machining operation. Since the model captures the physics of tool wear and machining heuristics, it is more robust than a purely data-based model.
Semi-Analytical Approach for Derivation of an Equivalent Modal Friction-Damping Ratio and its Application in a Self-Excited Drilling System
Authors: Kulke Vincent , Ostermeyer Georg-Peter , Tergeist Mathias , Hohl Andreas 
Published: January 2020

Abstract
In this article, friction-based damping principles and their suitability for dampening self-excited torsional oscillations in drill strings are investigated. Analytical and semi-analytical solutions based on a modally reduced model are derived by approximating the dynamic behavior with the Harmonic Balance method. The results are validated through time-domain simulations, and limitations of the method are shown. The method enables consideration of the damper position that determines the local amplitudes experienced by the damper. In analytical solutions, the damper location is represented by the local value of the mass-normalized mode shape. The analytical approach can be used to calculate and optimize an equivalent damping ratio for every torsional mode based on the parameters and placement of the friction damper. The provided damping can then be used to estimate the stability of critical torsional modes.
Digital Twin: Concept of Hybrid Programming for Industrial Robots — Use Case
Authors: Kuts Vladimir , Sarkans Martinš , Otto Tauno , Tähemaa Toivo , Bondarenko Yevhen 
Published: January 2020

Abstract
Modern Industrial Robot (IR) programming process is mainly performed by using three different methods — manual, offline, and online programming. Each of these methods has various advantages and disadvantages. Prominent automotive industries often use a combination of them, as there is no way to avoid one or another form of programming on one factory. However, the use of a combination of different programming methods is time-consuming and demands the operator’s presence on site for reconfiguration of the IR. The primary goal of this study is to introduce and test the concept of a hybrid IR programming method, which combines both: offline and online robotic cell design, programming, and re-configuration methods. Testing of this method is based on fully synchronized robotic cell’s Digital Twin (DT), developed in Industrial Virtual and Augmented Laboratory of Tallinn University of Technology. Usage of the virtual replica allows to plan and program robotic cell on the means of telepresence and interfere with the predefined path of the robot by online programming method. Moreover, this approach reduces the time for robotic cell design and re-programming, enables to minimize downtime of the robotic cell on the factory shop floor. Included Virtual Reality (VR) environment allows simulating a full-scale operator presence on site. Thus, the proposed approach supports an immersive and safe environment for the IR and similar equipment programming purposes.
Development of a New Stoichiometric Equilibrium-Based Model for Wood Chips and Mixed Paper Wastes Gasification by ASPEN Plus
Authors: Safarianbana Sahar , Unnthorsson Runar , Richter Christiaan 
Published: January 2020

Abstract
Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.
Explosion Testing of Relief Valves for Underground Refuge Alternatives
Authors: Homer John , Whitson Ashley , Whisner Bruce , Yonkey Jeff , Yantek Dave 
Published: January 2020

Abstract
Federal regulations require refuge alternatives (RAs) to be installed in underground coal mines. RAs provide miners safe shelter from life-threatening environments during a mine emergency when escape is not possible. Built-in-place (BIP) RAs require ventilation systems that supply breathable air to occupants. Relief valves provide critical functions to the ventilation system by limiting pressure within the RA, allowing ventilation air to exit while preventing contamination ingress, and protecting occupants from external pressure due to mine explosions. As such, relief valves for BIP RAs must be developed and tested to ensure pressure relief, adequate airflow, and the ability to withstand a 103-kPa (15-psi) blast overpressure with a duration of 0.2 seconds.
The National Institute for Occupational Safety and Health (NIOSH) has published research on relief valve opening pressures and airflow rates. However, the ability of RA relief valves to withstand a survivable mine explosion must be demonstrated. As such, NIOSH researchers tested the ability of RA relief valves to withstand overpressure representative of a survivable mine explosion. For this, seven relief valves were subjected to 103-kPa (15-psi) target overpressure waveforms, produced using methane-air explosions within a fixed-volume enclosure. All seven relief valves survived the overpressure testing, maintained normal performance, and did not incur any critical component deformation. One instance of valve leakage was observed during the tests.
This paper presents the methodology and results of testing the ability of RA relief valves to withstand a survivable mine explosion. Information in this publication can be used for evaluating relief valve design and determining parameters critical to their ability to reliably withstand a survivable mine explosion and protect RA occupants. Research presented in this paper is applicable to testing and improving RA designs for underground coal mines, and could also be extended to similar applications and industries involving explosion testing.
Optimizing Process and Geometry Parameters in Bulging of Pipelines
Authors: Memon Shabbir , Mohammed Obaidur Rahman , Koppisetty D. V. Suresh , Lankarani Hamid M. 
Published: January 2020

Abstract
The objective of this work is to determine the optimum process and geometry parameters to attain maximum bulge height without necking / splitting failure. The effect of process parameters on strain path and its correlation with bulge height is also carried out., ANOVA is used to study the relative contribution of geometry properties, process parameters and tube thickness. It is found that the strain hardening exponent has the highest impact on bulging followed by plastic anisotropy and thickness of tube has a relatively lesser contribution to limit strains of tube bulging. The effects of process parameters, at a specific bulge height, are studied on effective strain distribution and thinning distribution, the homogeneity of which is expressed in the terms of real Kurtosis value. It is concluded that optimum process parameters not only gives less thinning and greater bulge height, it also gives more uniform deformation pattern (thinning and effective strain). The validation of optimum process parameters obtained through Taguchi is carried out using additive model and it is found that the observed value is well in agreement with the predicted value. It is also found that friction has a negative impact on bulge height as well as thinning. This is because higher friction resists the flow of material and causes the material to thin more rapidly at the critical area where necking is taking place. It is also found that bulge height is maximum at higher pressure and higher bulge length and thinning is minimum at lower pressure and higher bulge length.
Climbing Bloom’s Taxonomy With Jupyter Notebooks: Experiences in Mechanical Engineering
Authors: Weber Bryan W. 
Published: January 2020

Abstract
Active learning techniques are well known to improve student outcomes and shift their thinking higher on Bloom’s Taxonomy. In this paper, I will present experiences from my implementation of active learning in sophomore-level Mechanical Engineering thermodynamics classes using Jupyter Notebooks. Jupyter Notebooks are a web-based programming environment widely used in software and other industries that allows students to combine code with equations and explanations of their work. By using this software to solve open-ended design problems, students move from the Remember, Comprehend, and Apply steps of Bloom’s Taxonomy to the Analyze, Synthesize, and Evaluate stages. Successfully integrating Jupyter Notebooks with these classes has required a shift in the focus of contact hours, going from didactic presentation of material to active practice with problem-solving techniques; most class material has been moved online. This approach has been successfully implemented over several semesters, but there are nonetheless still improvements to be made, which are discussed at the end of the manuscript.
Application of a Hybrid RANS-LES Method to Free Shear Layers
Authors: Catalano P. 
Published: January 2020

Abstract
This paper presents the application of the XLES (eXtra Large Eddy Simulation) method to relevant test-cases. The mixing between two boundary layers and between a wake and a boundary layer are discussed. The first test case considers the mixing layer that forms at the end of a splitting plate. Two boundary layers with different free-stream velocities flow on the upper and lower side of a flat plate and join at the trailing edge forming a free shear layer. The second test case represents a mixing between the 2-D wake originating downstream an airfoil and the 2-D boundary layer developing over a flat plate placed beneath the airfoil. This application is representative of flows over multi-element configurations where the wake coming from the slat merges with the boundary layer of the main component. The method has shown to be effective reducing the modelled turbulence and providing resolved turbulence in the regions of the field treated in LES mode. The “grey-area” issue has been highlighted. This is likely connected to the stochastic character of the model.
Reliability-Based MDSDO for Co-Design of Stochastic Dynamic Systems
Authors: Azad Saeed , Alexander-Ramos Michael J. 
Published: January 2020

Abstract
Optimization of dynamic engineering systems requires an integrated approach that accounts for the coupling between embodiment design and control system design, simultaneously. Generally known as combined design and control (co-design) optimization, these methods offer superior system performance and reduced costs. Despite the widespread use of co-design approaches in the literature, not much work has been done to address the issue of uncertainty in co-design problem formulations. This is problematic as all engineering models contain some level of uncertainty that might negatively affect the systems performance, if overlooked. While in our previous study we developed a robust co-design approach, a more rigorous evaluation of probabilistic constraints is required to obtain the targeted reliability levels for probabilistic constraints. Therefore, we propose and implement a novel stochastic co-design approach based on the principles of reliability-based design optimization (RBDO). In particular, a reliability-based, multidisciplinary dynamic system design optimization (RB-MDSDO) formulation is developed using the sequential optimization and reliability assessment (SORA) algorithm, such that the dynamic equality constraints are satisfied at the mean values of random variables, as well as their most probable points (MPPs). The proposed approach is then implemented for two case studies to indicate the impact of including reliability measures in co-design formulations.
A Biomechanical Investigation of Collagen, Platelet-Rich Plasma, and Mesenchymal Stromal Cells on the Achilles Tendon in a Rat Model
Authors: Austin Brittany , Marie Hazel , Fagan Diana , Vanasdale Jared , Drew Stuart 
Published: January 2020

Abstract
This study aims to biomechanically compare four different treatment methods for repair enhancement in Achilles tendon rupture in rats: collagen, collagen and platelet-rich plasma (PRP), collagen and mesenchymal stromal cells (MSC), and a combination of collagen, platelet-rich plasma and mesenchymal stromal cells (CPM) at one and two week healing periods. This study included ninety Lewis rats weighing approximately 200–300 g. Ten rats were used as donors for MSC and PRP. For the remaining eighty rats, the right leg was completely transected 6 mm proximal to the calcaneus bone, suture repaired, wrapped in CollaTape (CoTa), and then closed. An injection of PRP, MSC, or PRP and MSC was given at the wound site to the applicable groups. After one or two weeks recovery time, the rats were sacrificed and both Achilles tendons were removed. The left tendons were used as virgin tissue controls. It was found that the maximum stress at failure, the total strain energy, the average modulus of elasticity, and the elastic strain energy all increase significantly from one week to two week recovery time. However, there was no statistical difference between treatment groups in any of the mechanical properties.
Interconnected Fluid-Filled Cells Design for Reduction of Linear Acceleration and Force Transfer to Prevent Concussion
Authors: Lindsay Alexandra R. , Chaudhary Usamah , Terry Taylor N. , Haghshenas-Jaryani Mahdi , Wijesundara Muthu B. J. 
Published: January 2020

Abstract
Regardless of efforts in improving helmet technologies, sport related concussions continue to be a problem. In an effort for advancing helmet liners, this research investigated a design comprised of interconnected fluid-filled cell structures that consist of a primary cell connecting to one or more secondary cells through a channel. When the primary cell undergoes impact, it deforms and pushes the fluid from the primary to secondary cells, which expand accordingly. This fluid motion absorbs the impact and dissipates energy, thereby reducing the force and acceleration transfer to a contacting body. Structures made with two hyper elastic polymers, silicone and polyurethane, were investigated in simulation and experimentation. For both materials, increasing the number of secondary cells in the structure will decrease the amount of force transfer and resulting acceleration. The optimized design, with one primary and two secondary cells, showed reduction of force by 25.2% and resulting acceleration of 80.7 m/s2 when using silicone, while cells made of polyurethane showed a 33.5% reduction of force and resulting acceleration of 72.5 m/s2. In comparison, a commercial liner (Vengeance DCT TPU Lateral Helmet Liner by Schutt® tested using the same test procedures, showed reduction in force by 24.3% and resulting acceleration of 87.0 m/s2.
Investigating the Purge Flow Rate in a Reactor Scale Simulation of an Atomic Layer Deposition Process
Authors: Nwanna Emeka Charles , Coetzee Rigardt Alfred Maarten , Jen Tien-Chien 
Published: January 2020

Abstract
This paper investigates the purge flow rate in a reactor scale simulation of an Atomic Layer Deposition (ALD) process. A three-dimensional numerical analysis approach was implemented in the ALD process to fabricate thin films of aluminium oxide (Al2O3). Despite the abundance of literature on the specific use of, and increase in deposited material through the process of ALD, limited studies exist on the physical and chemical processes that occur during the growth of ALD. Previous literature has indicated that purging has presented a major challenge in the effective deposition rate of the ALD process. The precise purge flow rate has also been greatly contended. The importance of the purge sequence within the ALD process cannot be overemphasized. The term purge sequence refers to the essential property that defines the ALD advanced nano-fabrication technique in producing ultra-thin film. Therefore, this study focused on the purge flow rate effects of the ALD process. The reactants employed in the simulation process were trimethyl-aluminium (TMA) and ozone (O3) as the metal and oxidant precursors, respectively, and inert argon as the purge gas. Numerical simulations were carried out at a stable operating pressure of 1 torr, with a substrate temperature of 200°C, and three purge flow rates of 20, 10 and 5 sccm, respectively. An extended ozone exposure is crucial to in providing an adequately oxidized substrate. It is discovered that the 5 sccm flow rate shows, superior mass fractions, unity surface coverage and a time extensive surface deposition rate. The 20 sccm, 10 sccm and 5 sccm purge flow rate growth obtained a 0.58, 0.92, and 1.6 Å/cycle, respectively. The findings revealed close similarities to experimental behaviours and recorded growth.
Structural Design and Performance Analysis of a Deployable Vehicle Shelter With Hybrid FRP Composites and Aluminum
Authors: Wang Jinxi , Sun Lingyu , Li Lijun , Duan Jianyu 
Published: January 2020

Abstract
As a movable workspace, a deployable vehicle shelter has the advantages of easy transportation, good environmental adaptability, convenient maneuverability and large expansion space. Therefore, it has been widely applied in engineering rescue, medical security, living reserve, building, tourism and other fields. This paper aims to design the structure of a lightweight shelter assembly whose deployable mechanism is proposed for multi-level deployable vehicle shelter and whose steel frame and outer panel are replaced by aluminum and Glass Fiber Reinforced Polymer (GFRP) composites to reduce the weight of shelter. Additionally, the structural strength and stiffness are analyzed by the finite element method (FEM) under typical operation loads, such as bending, torsion, hard brake, turn, as well as modal analysis. This study could contribute to the knowledge for the lightweight design and engineering application of deployable vehicle shelters.
Definition and Evaluation of Induced Geometry for Design
Authors: Fischer Bryan , Morse Edward 
Published: January 2020

Abstract
Certain classes of parts include geometry that is inadequately addressed in current product definition standards. In some cases, the form of this geometry needs to be specified independently from the surface details. Examples of this include formed screens and meshes, as well as “rigidized” sheet metal components, tubular structures, and additively manufactured lattices. In each of these cases, the important functional geometry is related to a series of contact points or mid-points that are intended to conform to the designed profile. This paper seeks to more carefully examine the challenges associated with this geometry and the specifications needed to define and control it, and it reviews existing tools and techniques that may be applicable in meeting these challenges.
The Effect of Mixing Promotors on Sweeping Gas Membrane Distillation System Performance
Authors: Alqsair Umar F. , Alwatban Anas M. , Alshwairekh Ahmed M. , Krysko Robert , Alghafis Abdullah A. , Oztekin Alparslan 
Published: January 2020

Abstract
Computational fluid dynamics simulations were conducted to model the effect of adding mixing promoters in sweeping gas membrane distillation modules. Net-type spacers of 45° are placed in the feed side while membrane corrugation is employed with the tips of the corrugation pointing towards the permeate side. The membrane corrugation is of chevron type. The membrane is considered as a functional surface, and the vapor flux through the membrane is modeled using the Dusty-Gas model. The vapor flux equation couples the vapor pressure variation across the membrane with the feed concentration. The flow inside the channels with mixing promoters is considered turbulent. The k–ω SST turbulent model is used to model the steady-state turbulent structures inside the channels. The flow rate in the feed side is fixed, and the flow rate in the permeate channel is varied so that Rep = 1000,1500, and 2000 are considered. The inlet feed and permeate temperatures, and the membrane properties are fixed. The results indicate that the presence of mixing promoters increases the vapor permeation through the membrane by alleviation of the concentration and temperature polarization effects. The mixing promoters are more effective at high flow rates in both channels.