bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variable Stiff Revolute Joint for Compliant Robot
Authors: Sharma Manoj K. , Kitts Christopher 
Published: January 2022

Abstract
Over the past decades industrial robot manipulators have expanded throughout the automation landscape with their high degree of repeatability and accuracy. For safety reasons these robots are not allowed to share their workspace along with humans, which limits the various tasks that can be performed by a human-robot collaboration. To circumvent this limitation, a new kind of variable stiffness series elastic actuator is proposed as a joint actuator. This variable stiffness series elastic actuator has an ability to servo-control its joint stiffness, and provide a measure of the instantaneous joint torque. Soft joint intrinsically enhances safety by providing compliance in the event of an impact. These unique abilities play a crucial role in an intelligent robot control design that can scale down the risk factors in a field where humans and robots collaborate. This article presents the design of variable stiffness series elastic actuator, mathematical modeling, and calibration of the variable stiffness series elastic actuator.
Prediction of Hot Deformation Behaviors Under Multiaxial Loading Using Gurson-Tvergaard-Needleman Damage Model for Inconel 718 Alloy Thin Sheet
Authors: Mahalle Gauri , Kotkunde Nitin , Kumar Gupta Amit , Kumar Singh Swadesh , Nikhare Chetan P. 
Published: January 2022

Abstract
Inconel 718 is a high strength, precipitation-hardenable Ni-Fe-Cr-based superalloys, mostly used in nuclear and aerospace applications in extreme working conditions. In this work, hot deformation behavior of the Inconel 718 alloy sheet has been investigated at 700°C under multiaxial loading conditions. The forming behavior has been analyzed along three distinct deformation modes (biaxial stretch, plane strain, and uniaxial stress regions) and results were quantified using a Gurson-Tvergaard-Needleman (GTN) damage model. Firstly, uniaxial tensile tests have been performed at 700°C and quasi-static strain rates (0.0001–0.01 s−1) to identify the material constants of the damage model. Further, the standard Nakazima test has been conducted to describe the forming and fracture behavior along three deformation modes. Further, Marciniak-Kuczynski model using a GTN damage model with Barlat’89 anisotropic yield criteria have been used for theoretical prediction of failure strains for Inconel 718 alloy. This model shown a good prediction capability in terms of fracture strains. Subsequently, Finite element (FE) analysis of Nakazima test coupled with plastic and damage modeling has been carried out to predict failure behavior of the Inconel alloy. The FE predicted results showed good agreement with the experimental test in predicting the fracture behavior of the alloy. The presented results give a basis of optimal hot forming process of Inconel 718 alloy.
Analysis of Traction Electric Motors Used in Commercial HEV and BEV
Authors: Arriaga-Vigil Alfonso , Karamanis Eleftherios , Lopez-Parra Marcelo , Ricardo-Torres Osiris 
Published: January 2022

Abstract
The design of electric traction motors is a complex task since high-performance requirements must be met in terms of power and torque densities in the wide operation speed range, including volume and mass restrictions. Since the launch of the GM EV, in 1996, electrification has been increasing and hybrid and electric vehicle traction motors have incorporated constant improvements and very innovative designs. This paper reports on motor specifications of 16 of the most representative commercial hybrid and electric vehicles, additionally, presents a comparison of their special design features and performance. Although there are plenty of technical publications on electric traction motors and some of the commercial motors presented herein are very well known in detailed, the authors develop and present a finite element method and Ansys® Electronics Suite comparison, which is based on efficiency maps. The results show the chronological evolution of different mechanical configurations that have successfully been arranged to improve the performance of traction motors over the years. The main conclusion is that the geometry of the magnetic circuit is one of the most important characteristics and that high optimized designs are needed.
Optimal Interior Mounted Permanent Magnet Synchronous Motors MTPA and MPPA Control Based on Sliding Mode Approaches
Authors: Alnami Hashim , Pang Chengzong , Papineni Avinash , Wang Xin 
Published: January 2022

Abstract
This paper presents novel sliding mode control (SMC) approaches for Maximum Torque Per Ampere (MTPA) and Maximum Power Per Ampere (MPPA) of interior permanent magnet synchronous motors (IPMs). We first derive the first-order sliding mode control methods to improve the field oriented control’s resiliency against the external perturbations, extraneous noise and modeling uncertainties. And after that, we propose the higher-order sliding mode control to significantly reduce the chattering phenomenon which is inherent in the first order sliding mode control method. Based on the comparison studies, the conventional proportional-integral derivative based field oriented control shows sluggish response and is more sensitive to parameter perturbations and external torque disturbances. By introducing the novel sliding mode control methods, both of the speed and torque regulation performance of interior-mounted permanent magnet synchronous motor can be greatly improved. Computer simulation studies have shown the superior performance of the first-order and higher-order sliding mode controllers for interior permanent magnet synchronous motor speed and torque regulation applications.
A Comprehensive 3D FEM Model to Study Forces, Cutting Temperature and Residual Stresses During Vibration Assisted Hard Turning Considering Tool Cooling Cycle
Authors: Dutta Pranesh , Bartarya Gaurav 
Published: January 2022

Abstract
The use of hardened steel in the automotive industry has increased of late. For longevity of the component under fatigue loading, residual stresses play an important role. The fatigue life of a machined component improves when the nature of the residual stress profile generated is compressive. In the present work, the machining forces, tool tip temperature and the nature of the residual stress generated have been studied in Vibrating Assisted Machining (VAM) conditions where the tool vibrates at low amplitude and high frequency. The vibration makes the tool create a constant engagement and disengagement motion with the workpiece. A three-dimensional thermo-mechanical FEM model has been developed to study the effects of VAM on turning of hardened (62 HRC) AISI 52100 steels. The model predicted the radial forces with sufficient accuracy for continuous turning. The air cooling of the tool during disengagement from the workpiece, gives rise to convective heat transfer to the surrounding, resulting in efficient the cooling of the tool. The same has been verified by analysing the effect of vibrating velocity (Vv) on tool tip temperature. The intermittent nature of VAM decreased the average tool tip temperature. The residual stress generated at different cutting speeds under vibration (Vv) was also predicted. For larger Vv, the residual stress profile became more compressive compared to that generated in the conventional hard turning simulations.
Hardware-in-the-Loop Simulation for Large-Scale Applications
Authors: Krama Abdelbasset , Gharib Mohamed 
Published: January 2022

Abstract
The hardware-in-the-loop (HIL) testing methodology has recently gained wide acceptance from the scientific community worldwide, as it allows virtual or actual components of a complex system to be implemented and tested together with the controller in a real-time environment. In this paper, three different case studies are investigated to show the use of the HIL testing methodology in different disciplines. In the first case study, a shunt active power filter for power quality improvement in a distribution network is presented and investigated using the HIL methodology. In the first case study, a HIL platform for drill string system control has also been developed and its operational principle and hardware components are explained. In the third case study, a HIL testing platform was developed for high power induction motor driving drill string system, in which the drill string is studied together with the induction motor and a variable frequency drive to match real-world case scenarios. A variety of tests were performed to provide a comprehensive study on the effectiveness of the HIL testing platform on different applications that take advantage of state-of-the-art real-time simulators. The presented HIL infrastructure can be extended to accommodate different studies on other electromechanical systems.
Active Vibration Control of Piezoelectric Beam Using the PID Controller
Authors: Alnuaimi Mohammed , BuAbdulla Abdulaziz , Silva Tarcísio , Altamimi Sumaya , Lee Dong-Wook , Al Teneiji Mohamed 
Published: January 2022

Abstract
Vibration control using piezoelectric materials has been widely investigated over the past decades. Particularly, active controllers achieve greater vibration control over wider frequency ranges than other vibration control techniques. Active controllers make use of sensors, actuators, and control laws. While most researchers focus on improving the control law, investigations on the optimal placement of sensors and actuators remain much less explored. This work presents a simple and quick methodology to obtain the optimal placement of piezoelectric sensors and actuators on different electromechanically coupled systems, without using classical beam or plate structures or limiting assumptions (symmetrical bending, linear strain, etc.). Optimal placement of sensors and actuators is performed based upon two criteria: i) varying the number of piezoelectric layers used for sensing and actuation and ii) varying the position over the structure’s thickness. Each criterion (i and ii) is presented and discussed in a different study case. Results show that as the number of piezoelectric layers increases, vibrations are controlled more efficiently. However, stacking several piezoelectric materials is not easily feasible in practice, leading to a tradeoff between reducing vibrations (using more layers) and ease of assembly. As of criterion ii), optimal placement of piezoelectric sensors and actuators is the farthest possible from the neutral line since sensors generate larger signal output (increased sensor gain), and actuators apply larger momentum on the system reducing more vibrations.
Modular Design of Space Expandable Capsule Based on Origami-Inspired Structures and Stretchable Mechanism
Authors: Xiao Liping , Xu Zhao , Wang Ke , Kang Boqi , Wang Anping , Zhao Haifeng 
Published: January 2022

Abstract
The deployable structures based on origami have been widely utilized in the design of spacecraft structures. With the advantages of foldability and stowability, origami-inspired structures can be folded into a pre-designed shape to fit into the rocket envelope. In this study, a novel configuration of the modular expandable capsule was developed based on origami-inspired structures and stretchable mechanism. The whole capsule was composed of multiple identical units with origami structures. In each unit, the geometric parameters such as width and length were quantitatively designed, and their influence on the packaging ratio of each unit was discussed. The origami creases were treated as joints in the context of motion structures. Then, Denavit and Hartenberg (D-H) method was adopted to establish kinematic relation of capsule units. Through the theory of thick origami, motion characteristics of each unit with nonzero thickness panels can be constructed. Furthermore, stretchable mechanism with hyperelastic behavior was employed to resolve issues of geometric compatibilities during the process of folding and expanding. Finally, a prototype of origami-inspired capsule unit was fabricated to examine its motion behaviors. The results demonstrated the feasibility and effectiveness of such a design for potential space missions. This work can be treated as an innovative attempt to design large-scale space architectures, which can be assembled and constructed on orbit.
Interconnection of Renewable Resources, New Opportunity in the Rehabilitation of Old Small Hydropower Plant
Authors: Radulescu Bogdan Alexandru , Radulescu Victorita 
Published: January 2022

Abstract
In Romania, before 1990, numerous small hydroelectric power plants - SHP were realized for the electrification of isolated areas or small communities. Since 2007, a new concept concerning the operational parameters and yields has been implemented, and the functional SHPs have been re-evaluated. A massive environmental data monitoring campaign has started, creating an economically appropriate SHP database that can be associated with another renewable resource. This paper presents such a pilot station, the first realized in Romania near the Arges River, SHP Budeasa, interconnected with a wind power plant. Some local conditions and part of the realized database are briefly presented. Due to the increase in local demand for electricity, it was necessary to rehabilitate this SHP by associating it with 2 other power plants based on renewable sources. Each component of the pilot station is analyzed separately. After the commissioning of the wind farm an additional production of electricity was obtained, and the pilot station became profitable. From these benefits, the rehabilitation of SHP Budeasa started. The theoretical model, the essential steps in the physical realization and necessary conditions for interconnection are mentioned. The results obtained after seven months of operation and some economic aspects are finally mentioned.
A Case Study on the Effect of Uncertain Impacts of a Civil Aircraft Fuselage Section With Auxiliary Fuel Tank
Authors: Rayhan Saiaf Bin , Pu Xue 
Published: January 2022

Abstract
Crashworthiness studies the safety qualification of a vehicle (both airborne and road transports) to protect its occupants during an impact. For an aircraft, specific crashworthiness criteria like deformation pattern of the structure, absorbed kinetic energy profile, and acceleration responses experienced by the components and human body models must be met before it receives the transport certification. Therefore, in recent times, crashworthiness has emerged as a crucial field of study during the early design stages of aircraft along with other key parameters like weight reduction, load factor, and fatigue life estimation, etc. During the investigations of fuselage section crashworthiness, the solutions are mostly presented based on a perfect vertical impact without considering any effect of roll and pitch of the fuselage. However, in a practical situation, an abrupt event can be introduced with uncertain impact phenomena. Therefore, in this current research, a civil aircraft fuselage section with an onboard auxiliary fuel tank is studied based on five different uncertain impacts considering both different roll and pitch angles. A commercial explicit dynamic code Ansys Autodyn is adopted to investigate the virtual drop tests. Then the numerical outcomes are compared based on the seat trail acceleration responses, kinetic energy absorption of the components, and plastic deformation of the structure due to the investigated uncertain impacts. It is found that a minor change in roll and pitch angle has a significant effect on the acceleration responses of the accelerometers and the plastic deformation pattern of the fuselage section.
Multi-Working Conditions Topology Optimization of the Key Structure of the Climbable AGV Based on Level-Set Method
Authors: Fei Jiacheng , Zhou Yijun , Luo Chen 
Published: January 2022

Abstract
Compared with the traditional Automated Guided Vehicle (AGV), a climbable AGV is capable of moving on the flat ground and climbing vertically with the aid of the track. The mechanical condition of the supporting parts of the climbing AGV can change drastically in different working environments. Therefore, it is critical to optimize the structure of the key parts in a lightweight design. In this paper, the level-set topology optimization was conducted in order to achieve a better structure design of the key body parts. Under this proposal, mechanical analysis of the key body parts was carried out under typical working conditions. Various working conditions are taken into account during the optimization process through introducing weight coefficients computed by analytic hierarchy process (AHP) method. And the casting constraint was added to improve the manufacturability of the optimization result. Then the topology optimization model under multi-working conditions was established based on the level-set method. And the optimization result with a clear boundary was obtained. Finally, the optimization result was analyzed with the finite element method. Compared with the initial structure, the weight of the optimized structure is greatly reduced by 42.64% in the testing case while the mechanical properties of the optimized structure still meet the design demands. The same method can be extended to optimize other parts to reduce the total weight of the climbable AGV.
Emissions Reduction of a Direct Injection Diesel Marine Engine by Adding Hydrogen to the Inlet Manifold
Authors: Tealdo Carlos , Deutsch Jorge Alex 
Published: January 2022

Abstract
Global Warming is imminent. Emissions must be cut immediately. However, there are many challenges in reducing air pollution. It must be a cheap, abundant, efficient solution that occupies a small space and can be retrofitted to existing diesel engines.
The aim of this experiment is to explore the effect of adding Hydrogen to diesel engines. An experiment was conducted on a single-cylinder engine, under diverse running conditions with different flow rates of hydrogen.
The experiment is intended to prove that hydrogen injection adapts to engine operation without major modifications. Subsequently, various tests were conducted to measure the engine emissions.
This research made in diesel engines gradually blend hydrogen into it seeking for lower emissions in an effort to comply with new IMO regulations in old vessels engines, to increase their lifespan, it aims to be an alternative for scrubber, with the advantage of no sludge or waste is produced.
Nonlinear Vibrations of Rotor-Bearing Systems Supported by Squeeze Film Dampers Due to Unbalance Excitation
Authors: Sevencan Furkan , Cigeroglu Ender , Baran Özgür Uğraş 
Published: January 2022

Abstract
In this paper, nonlinear dynamic behaviors of a multi-mass flexible rotor-bearing system supported by short length Squeeze Film Damper (SFD) due to the unbalance excitation are presented. The rotordynamic model of the system is developed by using 1D Timoshenko beam elements for flexible shafts, lumped inertias for disks, linear springs and viscous dampers for bearings and structural damping for the system. The nonlinear SFD model is based on the analytical solution of Reynolds equation for open ends short length SFDs assuming circular-centered orbit motion. The SFD’s nonlinear damping coefficient matrix and mass coefficient matrix generated because of fluid inertia are obtained. In this model, rotor system matrices and nonlinear SFD coefficient matrices are incorporated to obtain the full system mass, gyroscopic, damping and stiffness matrices. Harmonic Balance Method (HBM) is used to represent the resulting nonlinear differential equations of motion as a set of nonlinear algebraic equations. Newton’s Method with arc-length continuation is utilized as the solution method for the set of nonlinear algebraic equations obtained. A rotor of a small turbojet engine, details of which is available in the literature, is considered as an example. Different nonlinear responses of the rotordynamic system are investigated in order to observe the effects of SFD’s diameter, clearance and length parameters and the amount of unbalance loadings and their locations.
Incorporation of Blade Twist and Non-Uniform Inflow Effects In Undergraduate Helicopter Aeronautics Whirl Stand Laboratory
Authors: Paquin Jeremy , Harris Evan , San Martin Emma , Kirby Dennis , Melnyk Richard , Humbert Nathan 
Published: January 2022

Abstract
Flight and aerodynamics laboratory experiences have supported the aeronautical engineering courses in the United States Military Academy’s mechanical engineering program for over 50 years. Whirl stands are the rotary-wing equivalent of wind tunnels; they are used to generate experimental data on small- or full-scale rotor systems. The helicopter whirl stand laboratory is a cornerstone event in the program’s Helicopter Aeronautics course, used to reinforce students’ understanding for predicting and calculating hover performance data. The experimental apparatus includes a remote control (RC) helicopter mounted to a static test stand, instrumented with load cells to measure lift and torque. The helicopter is capable of varied revolutions per minute (RPM) and collective blade pitch. Control of the apparatus and measurement readings occur from behind a protective wall with an observation window. The objective of the laboratory is to compare the results of predictive analyses, conducted using Blade Element Theory (BET) and Blade Element Momentum Theory (BEMT), to experimental data. Students calculate the coefficient of thrust based on collective pitch angles and atmospheric conditions using an iterative approach in numerical analysis software. A recent effort appreciably improved the lab by adding two experimental twisted-blade cases in addition to the original untwisted blades. The ability to change between the original and updated (twisted) blades offers insight into the advantages and disadvantages of each in hover. The upgraded blades were designed internally by students to match the original rotor diameter, outsourced for precision manufacturing, and tested for incorporation into the laboratory. Overall, the upgraded laboratory offers a relevant, comprehensive application to deepen students’ conceptual understanding of rotorcraft aerodynamics, laboratory procedures, and modeling principles taught in the course.
High-Damping Viscoelastic Material Monitoring Using Sub-Resonator Enhanced Electro-Mechanical Impedance Spectroscopy
Authors: Lu Runye , Shen Yanfeng 
Published: January 2022

Abstract
This paper presents the Electromechanical Impedance Spectroscopy (EMIS) method employing a novel piezoelectric wafer active sensor (PWAS) with sub-resonators, which can generate additional resonant peaks to enhance the impedance signature. In order to develop an in-depth understanding of the mechanism behind the sub-resonator effects, an analytical investigation is conducted first. The theoretical solution for the impedance of the new sub-resonator PWAS transducer is derived. Furthermore, numerical simulations are carried out to demonstrate the effectiveness of the new transducer to create additional resonant peaks. Harmonic analysis of coupled field finite element (FEM) models is conducted. Material degradations are modeled by altering the material properties like density and elastic modulus. Comparative investigations are carried out with both conventional PWAS transducers and sub-resonator PWAS transducers. EMI damage indices based on the spectral amplitude and frequency variation features are used to quantify the material degradation and simultaneously prove the superiority of the sub-resonator PWAS over the conventional PWAS. Additionally, a high-damping dog-bone specimen is employed to conduct the creep experiment lasting for twenty-four hours with a recording interval of two hours. The impedance spectra are obtained by the Bode-100 impedance analyzer. The experimental results further demonstrate the improved sensitivity of the sub-resonator transducer, which is in good agreement with the theoretical and numerical findings. The paper finishes with summary, concluding remarks, and suggestions for future work.