bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance Variation of Nano-Scaled Devices in 3D-IC Packaging Architecture Induced by TSV Residual Stress
Authors: Lee Chang-Chun , Huang Pei-Chen , Wang Chi-Wei 
Published: January 2020

Abstract
Through-silicon via (TSV) technique, is widely adopted as the vertical interconnection technology of three-dimensional integrated circuit packaging architecture. However, fabrication process-induced residual stress occurred in TSV during annealing and introduced the subsequent thermal–mechanical stress into silicon-based interposer. Aforementioned residual stress will affect the performance and electric stability of p-type metal-oxide-semiconductor field-effect transistor (pMOSFET) located around TSV. Accordingly, this study is focused on the influences of TSV layout with intrinsic residual stress on concerned pMOSFET performance. Process-oriented finite element analysis (FEA) is performed to simulate stress distribution of pMOSFET when concerned device channel region was affected by TSV residual stress and embedded SiGe alloy. To conquer the difficulty of FEA construction on TSV and pMOSFET with significant scale mismatch in same FEA model, the global–local submodeling technology is adopted to manage the balance between model complexity and numerical convergence. The residual stress magnitude effect of different designed TSV diameter on concerned channel stress components is extracted to estimate its influence on pMOSFET with scaled gate width. The presented results indicated that increased TSV residual stress could obviously reduce performance of concerned device. It should be noted that the S/D stressor remarkably dominated mobility gain of strained pMOSFET.
Convergence of PIV Measurements at the Inlet of a Turbocharger Compressor
Authors: Banerjee Deb , Selamet Ahmet , Dehner Rick , Miazgowicz Keith 
Published: January 2020

Abstract
Particle Image Velocimetry has become a desirable tool to investigate turbulent flow fields in different engineering applications, including flames, combustion engines, and turbomachinery. The convergence characteristics of turbulent statistics of these flow fields are of prime importance since they help with the number of images (temporally uncorrelated) to be captured in order for the results to converge to a certain tolerance or with the assessment of the uncertainty of the measurements for a given number of images. The present work employs Stereoscopic Particle Image Velocimetry to examine the turbulent flow field at the inlet of an automotive turbocharger compressor without any recirculating channel. Optical measurements were conducted at five different mass flow rates spanning from choke to surge at a corrected rotational speed of 80 krpm. The velocity fields thus obtained were used to analyze the convergence of the mean (first statistical moment) and variance (second statistical moment) at different operating conditions. The convergence of the mean at a particular location in the flow field depends on the local coefficient of variation (COV). The number of required images for the mean to converge to a particular tolerance was also found to follow roughly a linear trend with respect to COV. While the convergence of the variance, on the other hand, did not appear to show any direct dependence on the coefficient of variation, it takes significantly more images than the mean to converge to the same level of tolerance.
Introduction of Prevention Engineering Into the Mechanical Engineering Curriculum
Authors: Bzymek Zbigniew M. , Brown Eliot 
Published: January 2020

Abstract
In today’s fast growing world, the economy — especially the field of technology and production — are developing very rapidly. Engineering design that would predict the results of this rapid development and equip the society with tools to control them, faces a big challenge. Rapidly developing technology brings many benefits to humanity and makes life easier, friendlier and more comfortable. This has been the case for thousands of years as new branches of engineering were born and came to serve society. One might say that engineers have the privilege of creating a bloodless and peaceful revolution resulting in easier and happier lives for people.
At the same time, such fast developing technology creates traps and dangers, and may cause harm. The inventions of Alfred Nobel, Samuel Colt and Eliphalet Remington, for example, or nuclear research have all brought significant technological progress to nations and societies but have also brought harms and disasters affecting both societies and individuals. The role of engineering design is to predict these harmful actions and plan to neutralize or eliminate them, or even change them from harmful into friendly. Such actions follow the way recommended by BTIPS (Brief Theory of Inventive Problem Solving) procedures [1], especially those using the Prediction module [2], [3]. When developing Prevention Engineering a system approach should be observed and hierarchy of systems established and defined. All systems should be designed in such a way that prevents harm to humans and the natural world.
Recommendations for introducing Prevention Engineering as a branch of engineering practice, and as an educational and research discipline, should be created as soon as possible, and directions for introducing courses in Prevention Engineering design and practice should also be developed [4]. For example, personal protective equipment for individuals and groups as designed by ME and MEM engineering students in their courses might be considered as Prevention Engineering developments [5].
Defining and formulating Prevention Engineering as a new branch of engineering is necessity in our times. In every step of our lives we face the challenge of preventing harms and destruction that can be done by the contemporary surrounding world. The goal of Prevention Engineering [PE] is to make the world safe. Prevention and safety are connected, prevention is an action, while safety is the condition or state that we are trying to achieve. Preventative actions can be based on the recommendations of BTIPS - Brief Theory of Inventing Problem Solving - and may use BTIPS’s approach [4], [5].
The reasons for the development of PE have already been described [6]. Each of these should be pointed out and preventative measures should be found. Adding these preventative measures to the contemporary engineering research, practice and education, and especially reflecting them in the engineering curriculum would be useful now and will also be necessary in the future [7], [8].
Influence of Oil Volume Upon Operation and Performance of Screw Machines With High Built-In Volume Ratio
Authors: Stosic Nikola 
Published: January 2020

Abstract
A performance calculation of a screw compressors with increased built-in volume ratio was performed and presented in this paper to establish how increased built-in volume ratio influences compressor efficiency. It is known that screw compressors have limited built-in volume ratio which is determined by their standard discharge port size and position close to the bores cusp. However, if the discharge port size is reduced beyond its cusp position, the screw machine built-in volume may be increased. In such a case, influence of the oil volume in the air-oil mixture of oil-flooded compressors increases the machine built-in volume further. A performance improvement achieved if the built-in volume ratio is doubled in comparison with the standard port during the machine operation at high pressure ratio of more than 20, is up to 26% in the specific power and adiabatic efficiency. This confirms superiority of the reduced size high pressure port for compressors which operate at high pressure ratio.
Research on Wall Thickness Uniformity of Hollow Axles by Three-Roll Skew Rolling
Authors: Zhang Song , Shu Xuedao , Xu Chang , Wang Jitai , Li Zixuan 
Published: January 2020

Abstract
The paper describes wall thickness non-uniformity of hollow axles by three-roll skew rolling and the proposed improved measure. According to the characteristics of the three-roll skew rolling process, a simulation model of hollow axles by three-roll skew rolling was established. In order to study the influence of different process parameters on wall thickness uniformity, five main process parameters (feed angle, rolling angle, length of forming zone, axial feed speed, temperature) were selected and imported into the simulation model for simulation analysis. The results show that the optimum process parameters are feed angle 7°, rolling angle 30°, length of forming zone 5mm, axial feed speed 20–30 mm/s and temperature 1050°C with the same conditions, and the maximum deviation of the wall thickness is 0.7mm. The uneven wall thickness of the axle body is caused by the metal reflow, which can be solved by compensating for the radial feed of the roller or by secondary machining. Reasonable selection of process parameters can significantly improve wall thickness uniformity of hollow axles by three-roll skew rolling.
Improvement of Axial Tension Distribution of Bolted Joints Tightened by Calibrated Wrench Method From Viewpoint of Quality and Process Control Using Elliptical Confidence Limit
Authors: Hareyama Soichi , Manabe Ken-ichi , Kobayashi Satoshi 
Published: January 2020

Abstract
When tightening a large number of bolted joints, the calibrated wrench method is used. Since this method is indirect, the axial tension varies greatly in many cases. However, the calibrated wrench method is still widely used because of the simplicity of the tool and easy standardization. When the tightening torque and axial tension are considered to be two independent random variables, the axial tension (stress) is distributed within an elliptical confidence limit. Conventionally, it is thought that the shape of this distribution is a rhombus. Considering the permitted limit for a working load (stress) on a bolted joint, the elliptical variation has a larger margin to the yield point than that of a conventional rhombus. On the basis of this feature, we show in this paper that a higher tightening target torque and a higher axial tension can be set than before. By applying the elliptical confidence limit, one can obtain higher tightening torque and initial axial tension than the conventional values within a smaller range of variations. In this study, in the case of tightening a large number of bolted joints at factories and so forth, tightening reliability is considered as a problem associated with quality or process control and a probabilistic statistical method is investigated. Finally, we carry out analysis to establish the optimum tightening torque for bolted joints.
A Study of Corner Separation in a Linear Compressor Cascade Based on SBES Model
Authors: Lu Bingxiao , Teng Jinfang , Zhu Mingmin , Qiang Xiaoqing , Ma Wei 
Published: January 2020

Abstract
Under the condition of large incidence angle in an axial compressor, corner separation will occur in corner region. When the blade loading increases, there may even be corner stall. This three dimensional complex flow structure is high intermittent and unsteady. In order to study the flow mechanisms, a hybrid RANS/LES turbulence model (SBES) was used to simulate the corner separation in the cascade. Firstly, the evolution of vortical structures in the corner separation region were analyzed. The boundary layer and the backflow in the corner separation region encounter, forming vortices with opposite rotation and developing downstream continuously. This cause the unsteady flow in corner separation. In addition, the shedding of detached eddies at the trailing edge is another sources of unsteadiness. Secondly, based on studying the turbulent characteristics, it can be seen that there is active turbulent fluctuation in the corner separation region. The turbulence is high anisotropic because the distribution and the values of Reynolds stresses in different directions are quite different. Thirdly, the mechanism of bimodal phenomenon was explained in this paper. Bimodal means there are two peaks in the velocity probability histogram, it is found in the region between separated flow and non-separated flow. This indicates that there are two non-periodic switching flow modes. Through the analysis of this paper, we find that it is related to the development of large scale coherent vortical structures.
Electromigration Analysis of Power Modules by Electrical-Thermal-Mechanical Coupled Model
Authors: Kato Mitsuaki , Omori Takahiro , Goryu Akihiro , Fumikura Tomoya , Hirohata Kenji 
Published: January 2020

Abstract
Power semiconductors and modules are basic components of electrical infrastructure and are currently widely used in applications such as power conversion devices, industrial equipment, railways, and automobiles. Power modules are being developed with the aim of downsizing and increasing power output. With the larger current densities and higher operating temperatures associated with downsizing and increasing power output, degradation of power modules can occur as a result of electromigration. Electromigration is a phenomenon where atoms move due to the momentum transfer between conducting electrons and metal atoms. In addition, atoms are also moved by mechanical stress gradients and temperature gradients, so it is necessary to take into consideration the combined effects of electrical, thermal, and mechanical stress.
In this report, we describe an electrical-thermal-mechanical coupled analysis of electromigration in a bonding wire of a power module. First, the analysis is validated under the condition that the displacement of the wire surface is fixed. The distributions of vacancy concentrations and hydrostatic stress are almost equal to those in previous studies. Next, we present the influences of current density, temperature, and the displacement constraint on electromigration in a wire with a simplified shape. The analysis results confirm that the plasticity and creep should be taken into consideration in a bonding wire. This also confirm that vacancy concentration increase more rapidly by changing the displacement of the wire surface from the fixed condition to the free condition. Finally, we present analysis results for a bonding wire with the actual shape found in power modules. In this wire, a local concentration peak appear in the electrode terminal. The analysis results reveal that electromigration may affect not only void formation but also other failure phenomena in the bonding wire of power modules.
Analysis of CCR Expansion Joints
Authors: Kaul Sanjay , Gohil Rajpalsinh , Bisharia Parul , Roy Apoorva 
Published: January 2020

Abstract
The CCR (Continuous Catalytic Reforming) Platforming™ process is Honeywell UOP’s technology to convert low octane naphtha to high octane fuel or petrochemical feedstock such as aromatics. It is accomplished in a hydrogen atmosphere at elevated temperature and pressure across a platinum containing catalyst. The process flow is routed through heaters, blowers and coolers between reactors to maintain the heat of reaction. This article captures the procedure of selecting a suitable expansion joint for absorbing thermal movement between two important pieces of CCR equipment — the regeneration cooler and regeneration blower. It shows the design calculations of a universal hinged expansion joint operating at 0.14 MPa and 593°C in a pipe of 762mm diameter. The joint contains 5 single-ply INCOLOY 800H bellows with unreinforced convolutions. Design calculations of the expansion joint have been carried out using formulae prescribed in the Expansion Joints Manufacturers Association (EJMA) standard. Since it is difficult to quantify stresses using a movement test, the EJMA calculations have been verified against finite element analysis results of the bellows.
Structural and Thermal Loads for Hypersonic HEXAFLY-INT Vehicle
Authors: Cristillo D. , Scigliano R. , Di Benedetto S. , Cardone S. , Appolloni M. , Jasko A. 
Published: January 2020

Abstract
The purpose of this paper is to describe the procedures used to evaluate structural and thermal loads experimented by the HEXAFLY-INT Experimental Flight Test Vehicle (EFTV) and Experimental Service Module (ESM) during the ascent phase of the flight trajectory.
The HEXAFLY-INT payload will be launched by a rocket in a suborbital trajectory having an apogee at around 90 km and Mach 8. During this phase the structure is subjected to the launcher environment that includes several events which generates static, random and sinusoidal acceleration and by a fixed thermal distribution. The load conditions due to mechanical loads have been defined by dynamic analyses by means of MSC Nastran software. Thermal loads have been identified by using Ansys Workbench software.
The thermo-structural load conditions due to launcher environment have been defined by means of an interpolation procedure for transferring thermal distribution from Ansys to the Nastran FE Model.
Optimization of Mg Scraps Hydrolysis for Hydrogen Generation Using HCl: Experimental and Simulation
Authors: Akbarzadeh Rokhsareh , Ibrahim Qusai , Adeniran Joshua , Oviroh Peter , Jen Tien-Chien 
Published: January 2020

Abstract
Worldwide concerns on environmental pollution and the need for clean energy supply have attracted researchers’ interest for power generation using technology which not only is a clean technology but also utilizes the Mg scrap waste, a part of solid waste from electronic and automobile industries. The Mg scraps have been used for the hydrogen generation via hydrolysis. In an attempt we conducted the experimental study and optimization of hydrolysis of Mg scraps waste in the presence of HCl to generate hydrogen. This work optimizes the process of using Mg scraps to produce H2, Mg(OH)2 and MgCl2. The effect of different concentration of HCl on hydrolysis was studied to find the optimum concentration for the hydrogen generation. The most influencing parameters such as acid concentration of solution was selected and studied. The kinetic behaviour was analysed to determine the effect of different HCl concentration on hydrogen generation pattern. Numerical modeling was performed considering the chemical reaction using ReaxFF. The effect of the selected parameters on the system and the hydrogen concentration were investigated to predict the performance of the hydrolysis of Mg scraps in the designed reactor. This study proposes an eco-efficient method as it utilizes the Mg waste to produce hydrogen which is an energy carrier.
Introducing Sensor and Signal Processing Technologies With Hands-On Experiments and Software Designing Platform to Students in the Undergraduate Mechanical Engineering Program
Authors: Zhu Na 
Published: January 2020

Abstract
The hands-on ability and problem-solving skills have always been an essential requirement of engineering graduates, while there is an increased demand on the data processing skills recently. To improve such abilities for students, an elective course, sensor technology and signal processing, is introduced to the mechanical engineering undergraduate program. A combination of the lectures and lab activities is completed, where students learn the essential theory and structure of sensors and algorithms in signal processing, such as fast Fourier transform (FFT), windowing, filtering, etc., while applying the knowledge in hands-on activities and design both the simulation and experiment process. Student performance is evaluated in programming assignments, project reports, and exams. Assessment results for problem-solving skills, hands-on activities, and programming skills are presented in the paper.
Experiments on Nonlinear Vibrations of a Nuclear Fuel Rod Supported by Spacer Grids in Air and Submerged in Water
Authors: Amabili Marco , Balasubramanian Prabakaran , Ferrari Giovanni , Franchini Giulio M. , Giovanniello Francesco , Karazis Kostas , Painter Brian 
Published: January 2020

Abstract
For safety reasons, the nuclear fuel assemblies of Pressurized Water Reactors (PWR) must be able to withstand external excitations ranging from large amplitude seismic motions of the reactor to flow-induced vibrations from the surrounding coolant water. A nuclear fuel assembly is composed of long slender tubes, most of them filled with uranium pellets, maintained in a square array by spacer grids. The spacer grids provide a nonlinear flexible boundary condition with friction and micro-impacts that complicates the nonlinear dynamics. In order to improve safety margins in the design of nuclear fuel assemblies, it is of great interest to understand the influence of the spacer grids, as it relates to the overall structural stiffness and damping properties. In particular, the evolution of the vibration amplitude with increasing excitation forces is still undetermined.
In order to understand the nonlinear vibration response of a zirconium fuel rod filled with nuclear fuel pellets and supported by spacer grids, experiments were carried out in water and in air. They consisted of measuring the vibration response of the rod under a step-sine harmonic excitation at different force amplitude levels in the frequency neighborhood of the fundamental mode. If the excitation is large enough, the response of the rod displays nonlinear phenomena such as the shift of the resonant frequencies, multiple solutions with instabilities (jumps) and hysteresis, and one-to-one internal resonances. These experiments were carried out on zirconium tubes filled with axially unconstrained as well as axially blocked metallic pellets, which simulate the nuclear fuel. The zirconium tubes were tested both in air and immersed in water. The experimental data will be processed in the future by means of an identification procedure to extract the nonlinear stiffness and damping parameters of the system. An increase of the equivalent viscous damping with the excitation amplitude level is expected.
Experimental Determination of Layer-Specific Hyperelastic Parameters of Human Descending Thoracic Aortas
Authors: Bozzo Isabella , Amabili Marco , Balasubramanian Prabakaran , Breslavsky Ivan , Ferrari Giovanni 
Published: January 2020

Abstract
Heart disease is the second leading cause of death in Canada resulting in $20.9 billion annual healthcare expenditures [1,2]. Understanding the mechanics of the human descending thoracic aorta is fundamental for comprehending the development of pathologies and improving surgical prostheses. This study presents hyperelastic and viscoelastic material characterizations of the human descending thoracic aorta from twelve different donors, with a mean age of 49.4 years. The specimens were dissected into the three constituent layers: intima, media and adventitia. Evaluating the layer-specific opening angles led to the computation of the circumferential residual stresses. Uniaxial tensile tests of each layer, in both the circumferential and axial direction, were used to model the hyperelastic behavior according to the Gasser-Ogden-Holzapfel model (GOH). The storage modulus and loss tangent for the layers were obtained from uniaxial harmonic excitations at varied frequencies, to model the viscoelastic behavior with the generalized Maxwell model. The results showed a positive correlation between age and stiffness for all layers, both axially and circumferentially. Similar loss tangent values were found across the three layers. A large increase in the storage modulus from static to dynamic experiments further corroborates the importance of a viscoelastic model of the aorta, rather than solely hyperelastic.