bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital Twin: Collaborative Virtual Reality Environment for Multi-Purpose Industrial Applications
Authors: Kuts Vladimir , Otto Tauno , Bondarenko Yevhen , Yu Fei 
Published: February 2021

Abstract
Industrial Digital Twins (DT) is the precise virtual representation of the manufacturing environment and mainly consists of the system-level simulation, which combines both manufacturing processes and parametric models of the product. As being one of the pillars of the Industry 4.0 paradigm, DT-s are widely integrated into the existing factories, enhancing the concept of the virtual factories. View from the research perspective is that experiments on the Internet of Things, data acquisition, cybersecurity, telemetry synchronization with physical factories, etc. are being executed in those virtual simulations. Moreover, new ways of interactions and interface to oversee, interact and learn are being developed via the assistance of Virtual Reality (VR) and Augmented Reality (AR) technologies, which are already widely spread on the consumer market. However, already, VR is being used widely in existing commercial software packages and toolboxes to provide students, teachers, operators, engineers, production managers, and researchers with an immersive way of interacting with the factory while the manufacturing simulation is running. This gives a better understanding and more in-depth knowledge of the actual manufacturing processes, not being directly accessing those. However, the virtual presence mentioned above experience is limited to a single person. It does not enable additional functionalities for the simulations, which can be re-planning or even re-programming of the physical factory in an online connection by using VR or AR interfaces. The main aim of the related research paper is to enhance already existing fully synchronized with physical world DT-s with multi-user experience, enabling factory operators to work with and re-program the real machinery from remote locations in a more intuitive way instead thinking about final aim than about the process itself. Moreover, being developed using real-time platform Unity3D, this multiplayer solution gives opportunities for training and educational purposes and is connecting people from remote locations of the world. Use-cases exploits industrial robots placed in the Industrial Virtual and Augmented Reality Laboratory environment of Tallinn University of Technology and a mobile robot solution developed based on a collaboration between the University of Southern Denmark and a Danish company. Experiments are being performed on the connection between Estonia and Denmark while performing reprogramming tasks of the physical heavy industrial robots. Furthermore, the mobile robot solution is demonstrated in a virtual warehouse environment. Developed methods and environments together with the collected data will enable us to widen the use-cases with non-manufacturing scenarios, i.e., smart city and smart healthcare domains, for the creation of a set of new interfaces and multiplayer experiences.
Follower Behavior in Engineering Design Teams: Theoretical Constructs and Protocol Analyses
Authors: Plaunt Jessica A. , Ortiz Joshua B. , Agyemang Malena , Summers Joshua D. 
Published: February 2021

Abstract
The purpose of this research is to develop an understanding of followership behaviors in engineering design team situations by studying leadership behaviors. While leadership in engineering design teams has been studied from role, function or behavior, and individual characteristic perspectives, no studies are found that examined follower (helping) behavior in the context of an engineering design team. Understanding this behavior can lead to intervention strategies that might be employed to improve team dynamics and performance. To this end, a theoretical framework of follower behavior is defined based on a review of “helping behavior” from the literature. Characteristics of follower helping behavior include exhibiting citizenship, voluntary, extra-role, and not upsetting the status-quo. Specifically, a follower-leader is one who exhibits voluntary, “extra-role” (beyond expectation) behaviors in a professional setting done without upsetting the status-quo in a formal leadership setting. A model is developed that links leadership style, follower mindset, leader-follower relationship, influence tactics, follower behavior, and follower performance. The key behavior studied is helping behavior. This literature-based framework is exclusively based on survey study data. No research is found that focuses on studying the behaviors of followers from observational studies. Therefore, data presented from a previous protocol study is further reviewed in search of patterns of conversions of followers to leaders through behavior modeling. In the previous study, eight teams of four graduate engineering students were tasked with generating a function model for a design prompt. These teams were video recorded, and their behaviors coded for seven leadership actions. Of the eight design teams previously studied, there were 325 total leadership behaviors coded. A follower-to-leader behavior pattern was defined where a follower in one behavior immediately exhibited leadership behavior in the next coded activity. Of the activities coded, 131 (40.3%) possible follower helping actions have been identified. These are examined further to determine whether there is a correlation between the initial leadership behavior type and the following leadership behavior type. Patterns are also sought to determine how often the initial leader also changes to a follower in the subsequent activity. This study shows that there are follower patterns that are found in design activities. Further, these patterns are related back to the follower (helping) behavior model that is derived from the literature, specifically the influence tactics that include: inspirational appeals, consultation, supplication, and exemplification as well as the social exchange relationships of leader-member exchange (LMX), team-member exchange (TMX). Finally, this study provides suggestive evidence of patterns to motivate future systematic study of followership in engineering design.
Analytical Response of a Mass-Spring Oscillator With Time-Varying Inertia
Authors: Hassanpour Pezhmn 
Published: February 2021

Abstract
In this paper, the analytical response of a single-degree-of-freedom system with time-varying inertia is investigated. The system model represents several engineering systems, including resonant biosensors and load-carrying conveyor belts. The resonant biosensing applications, the mass of the resonator changes exponentially with time, while the mass of a load-carrying conveyor belt changes linearly. In general, the system’s inertial can increase or decrease. Considering that the first-order approximation of an exponential function yields a linear function, the latter function was used to model the variations of the mass with time with the assumption that the rate of change can be either positive or negative. The equation of motion is derived using newton’s second law of motion. Although the resultant ordinary differential equation has a similar form for both cases of increasing and decreasing mass, it is demonstrated that solving each case requires a different transformation, and the subsequent differential equations have different forms of analytical solutions. Each analytical solution is derived and compared with two corresponding cases: 1) the numerical solution of the differential equation with linearly-varying inertia, and 2) the numerical solution of the differential equation with exponentially-varying mass. Excellent agreement between the analytical solution and numerical solution of the system with linearly-varying inertia is demonstrated. This agreement confirms the validity of the analytical solution. On the other hand, the analytical solution agreed with the numerical solution of the system with exponentially-varying mass only for the initial moment of the integrations. This disagreement suggests that a linear approximation is not an accurate model for resonant biosensing applications where the mass variation is exponential by nature. Nevertheless, the linearly-varying mass model provides insights about how these systems behave differently from those with a constant mass. In particular, in this paper, it is demonstrated that an increasing mass system shows added damping effect. In contrast, a decreasing mass system behaves as if it has a “negative” damping coefficient. This finding is particularly significant because, along with other linear or nonlinear effects in the system that are not necessarily considered, it can produce catastrophically unwanted behaviors. Another impressive effect that is observed is the change of free vibration response of the system with time. For the case of increasing mass system, the frequency of oscillation of both linearly-varying and exponentially-varying systems decreases with time. In contrast, the frequency increases for the systems with decreasing mass. This phenomenon is expected because the frequency of free vibration is inversely proportional to the mass of the system.
Numerical Study of the Flow Inside a Modular Bag Filter From a Biomass Power Plant
Authors: Vinha Maria Inês , Silva João , Teixeira Senhorinha , Gomes Ana , Teixeira José Carlos 
Published: February 2021

Abstract
Nowadays, one of the most important issues in modern industrial power plants is air pollution. Solid particles are harmful to human health and are one of the main pollutants released through the combustion of biomass.
The main goal of this paper was to study the flow in a modular bag filter of a dedusting system implemented in a Biomass Power Plant, in order to improve the filtration of the solid particles coming from the biomass combustion. For this purpose, a numerical model using the ANSYS Fluent software was developed.
Initially, it was necessary to model the dedusting system in the software SolidWorks. Once this system had 10 modules and to facilitate the simulation in Fluent, only one module was modeled with proper simplifications. Once the geometry was modeled, it was exported to Fluent where the mesh was made, with special care in the inlet of the module, as it is the most critical zone for the simulation. It was simulated 4 cases, where the action of each individual filter was considered. The first case study considered the nominal operating conditions of a biomass power plant. Thereafter, two cases with different mass flow rates were simulated to assess if there were any differences in the flow inside the bag filter. Lastly, it was studied the influence of the vertical baffle size that is in the inlet of the module.
Comparing the four simulations, it was concluded that in the first three cases, the flow is very similar, with only a slight increase in the velocity in the study with higher flow, as expected. Furthermore, it was concluded that using a smaller vertical baffle, the flow would be improved, once the filters close to the inlet would be more used.
Evaluation of Control Algorithms on Mobile Robots for Collision Avoidance
Authors: Sungra Anshul , Fabien Brian 
Published: February 2021

Abstract
This paper describes the implementation of various algorithms to control the distance between a lead vehicle and a following (ego) vehicle. The ego robot equipped with a monocular camera and a rotating laser sensor (LDS). The monocular camera used for object detection using the Aggregate Channel Features (ACF) detection algorithm. The width of the bounding box generated by the detection algorithm had used to determine the distance between the lead and the following vehicles. Since this research focused on longitudinal autonomy, the data from the rotating laser sensor downsampled from 360 points to 30 points. These sampled points covered the front view of the vehicle. All data points transformed into a planar world coordinate (two-dimensional plane). The outputs of the camera and laser sensor (LDS) were fused to obtain accurate distance measurements for the lead vehicle. Sensor calibration had achieved by comparing sensor data with the ground truth values. Kalman Filter was used to implementing sensor fusion by combining perception data from the monocular camera and LDS for accurate position and velocity estimation. This calibration provided information about the sensor noise and deviation of sensor data from its ground truth values. These values helped to determine the error covariance matrixes of the Kalman filter. For implementation, the Robot Operating System (ROS)-MATLAB platform used to communicate between robot and host Personal Computer (PC). The experiments evaluated the performance of Proportional Control (P), Proportional-Integral Control (PI), and Model Predictive Control (MPC) in maintaining a minimum distance between the vehicles. For the MPC implementation in MATLAB, Model Predictive Control Quadratic Programming (MPCQP) solver was used to get the optimal solution for control output. The results show that the MPC yields faster response times when compared to P control and PI control. These algorithms evaluated during constant velocity and constant acceleration of the lead vehicle. The steady-state errors of P and PI controllers were around 0.1 meters (m) in both scenarios and 0 to 0.2m for constant velocity and 0 to 0.15m for ramp velocity, respectively. And for MPC, steady-state error varied from −0.05m to 0.05m in both the scenarios. This range in steady-state error was due to varying speed of the ego vehicle with time to maintain the minimum relative distance between the robots, and there was a communication delay in the system that also affected the behavior of the controllers. The MPC was more sensitive to communication delays. However, the effect of this communication delay was negligible to P and PI controllers. This sensitivity resulted in different velocity profiles for the ego vehicle in MPC and P or PI controllers.
Bridging Precipitate Microstructure and Mechanical Hardness of Nickel-Based Superalloy Through Artificial Neural Network Model
Authors: Li Yangping , Liu Yangyi , Luo Sihua , Wang Zi , Wang Ke , Huang Zaiwang , Zhao Haifeng , Jiang Liang 
Published: February 2021

Abstract
The attractive mechanical properties of nickel-based superalloys primarily arise from an assembly of γ′ precipitates with desirable size, volume fraction, morphology and spatial distribution. In addition, the solutioning cooling rate after super solvus heat treatment is critical for controlling the features of γ′ precipitates. However, the correlation between these multidimensional parameters and mechanical hardness has not been well established to date. Scanning electron microscope (SEM) images with different γ′ precipitates were investigated in this study, and artificial neural network (ANN) method was used to build a microstructure-mechanical property model. The critical step in this work is to extract different microstructural features from hundreds of SEM images. In order to improve the accuracy of prediction, the cooling rate was also considered as the input. In this work, the methodology was proved to be capable of bridging microstructural features and mechanical properties under the inspiration of material genome spirit.
Investigation of Grinding Force and Surface Integrity of IC10 in Creep Feed Grinding
Authors: Li Jun-chen , Wang Wen-hu , Jiang Rui-song , Liu Xiao-fen , Bo Huang , Jin Cheng-cheng 
Published: February 2021

Abstract
The IC10 superalloy material is one of the most important materials for aero-engine turbine blade due to its excellent performances. However, it is difficult to be machined because of its special properties such as terrible tool wear and low machined efficiency. The creep feed grinding is widely used in machining IC10 superalloy due to the advance in reducing tool wear, improving material removal rate and surface quality. The creep feed grinding is a promising machining process with the advantages of high material removal rate due to large cutting depth, long cutting arc and very slow workpiece, and its predominant features might have significant influence on the grinding force and surface quality for the workpiece. Hence, it is of great importance to study the grinding force and surface integrity in creep feed grinding IC10 superalloy.
In this paper, a series of orthogonal experiments have been carried out and the effects of grinding parameters on the grinding force and the surface roughness are analyzed. The topographies and defects of the machined surface were observed and analyzed using SEM. The results of the experiments show that the tangential force is decreased with the workpiece speed increasing. However, there is no significant change in tangential force with the increasing of grinding depth and wheel speed. The normal force is decreased with the workpiece speed increasing when the workpiece speed is less than 150 mm/min, but when the workpiece speed is more than 150 mm/min the normal force is increased tardily. Moreover, the normal force is increased sharply with the increase of grinding depth and is increased slowly with the increase of wheel speed. In general, the surface roughness is increased with workpiece speed and grinding depth increasing, while the trend of increase corresponding that of workpiece speed is more evident. The value of the surface roughness is decreased with wheel speed increasing. And it is found out that the main defect is burning of the IC10 superalloy material in creep feed grinding by energy spectrum analysis of some typical topography in this study.
Modeling Fatigue Crack Growth in CFRP Adhesively Bonded Substrate Using XFEM
Authors: Al-Dakheel Hussain , Temitope Idris , Albinmousa Jafar , Al-Athel Khaled 
Published: February 2021

Abstract
Carbon fiber reinforced polymers (CFRP) are crucial for many industries due to their superior material properties. CFRPs have strength and toughness that are comparable to metals but with the advantage of possessing lighter weight and higher corrosion resistance. Typically, structural parts are joined by bolts and rivets resulting in difficulties keeping the integrity of these joints. In CFRP joints, screw holes are stress concentration sites that may develop cracks, splits and delamination. Alternatively, adhesive bonding can be used as a joining method for CFRP substrates to overcome the disadvantages bolts and rivets.
Structural parts are usually subjected to cyclic loading. Therefore, fatigue is considered as a major design tool for these parts. Finite element analysis is a powerful tool for modeling damage in components. This paper aims to simulate fatigue crack growth in adhesively bonded carbon fiber reinforced polymer (CFRP) composite substrates using a double cantilever beam (DCB) specimen.
ANSYS XFEM is utilized to simulate the crack path using the enrichment technique to assign elements to the crack path. The model calculates the stress intensity factor (SIF) based on the domain integral over the contour around the crack tip. Then, it is converted at each sub-step to the energy released rate (ERR) which includes a correction factor estimated from the cohesive zone model (CZM). The model is idealized as a 2D geometry with the nodes at the unloaded edge and the corner being constrained in the longitudinal and the tangential directions, respectively. Displacement was applied at the other end of the specimen separating the two beams in a mode I condition. Finally, the number of cycles is estimated from Paris law.
To verify the proposed model, fatigue crack growth (FCG) tests were performed on an 8-layer unidirectional CFRP laminates (HexPly T700/M21) fabricated into DCB specimens. The substrates is joined by an aerospace grade adhesive (Araldite 420). The estimated energy release rate (ERR) using the developed finite element model is within 90% or more of that determined experimentally.
Numerical Modeling of Non-Affine Viscoelastic Fluid Flow Including Viscous Dissipation Through a Square Cross-Section Duct: Heat Transfer Enhancement due to the Inertia and the Elastic Effects
Authors: Hagani Fouad , Boutaous M'hamed , Knikker Ronnie , Xin Shihe , Siginer Dennis 
Published: February 2021

Abstract
Non-isothermal laminar flow of a viscoelastic fluid including viscous dissipation through a square cross–section duct is analyzed. Viscoelastic stresses are described by Giesekus modele orthe Phan-Thien–Tanner model and the solvent shear stress is given by the linear Newtonian constitutive relationship. The flow through the tube is governed by the conservation equations of energy, mass, momentum associated with to one non–affine rheological model mentioned above. The mixed type of the governing system of equations (elliptic–parabolic–hyperbolic) requires coupling between discretisation methods designed for elliptic–type equations and techniques adapted to transport equations. To allow appropriate spatial discretisation of the convection terms, the system is rewritten in a quasi-linear first-order and homogeneous form without the continuity and energy equations. With the rheological models of the Giesekus type, the conformation tensor is by definition symmetrical and positive-definite, with the PTT model the hyperbolicity condition is subject to restrictions related to the rheological parameters. Based on this hyperbolicity condition, the contribution of the hyperbolic part is approximated by applying the characteristic method to extract pure advection terms which are then discretized by high ordre schemes WENO and HOUC. The algorithm thus developed makes it possible, to avoid the problems of instabilities related to the high Weissenberg number without the use of any stabilization method. Finally, a Nusselt number analysis is given as a function of inertia, elasticity, viscous dissipation, for constant solvent viscosity ratio and constant material and rheological parameters.
A Numerical Study Into the Influence of Leading Edge Tubercles on the Aerodynamic Performance of a Highly Cambered High Lift Airfoil Wing at Different Reynolds Numbers
Authors: Abdelrahman Amr , Emam Amr , Adam Ihab , Hassan Hamdy , Ookawara Shinichi , El-wardany Ahmed 
Published: February 2021

Abstract
Through the last two decades, many studies have demonstrated the ability of leading-edge protrusions (tubercles), inspired from the pectoral flippers of the humpback whale, to be an effective passive flow control method for the stall phase of an airfoil in some cases depending on the geometrical features and the flow regime. Nevertheless, there is a little work associated with revealing tubercles performance for the lifting surfaces with a highly cambered cross-section, used in numerous applications. The present work aims to investigate the effect of implementing leading edge tubercles on the performance of an infinite span rectangular wing with the highly cambered S1223 foil at different flow regimes. Two sets; baseline one and a modified with tubercles have been studied at Re = 0.1 × 106, 0.3 × 106 and 1.5 × 106 using computational fluid dynamics with a validated model. The numerical results demonstrated that Tubercles have the ability to entirely alter the flow structure over the airfoil, confining the separation to troughs, hence, softening the stall characteristics. However, the tubercle modification expedites the presence of the stalled flow over the suction side, lowering the stall angle for the three mentioned Reynolds numbers. While, no considerable difference occurs in lift and drag before the stall.