bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Process Variants on Residual Stresses in Wire Arc Additive Manufacturing of Aluminum Alloy 5183
Authors: Derekar Karan S. , Ahmad Bilal , Zhang Xiang , Joshi Sameehan S. , Lawrence Jonathan , Xu Lei , Melton Geoff , Addison Adrian 
Published: November 2021

AbstractDevelopment of residual stress of high magnitude, to the extent of material yield strength and in some cases higher than yield strength, is one of the major challenges faced by components produced using the wire arc additive manufacturing (WAAM). This study focuses on aluminum alloy 5183 with respect to the residual stress formation and distribution in WAAM builds. Residual stresses were determined using the contour method. The effects of processing conditions, such as substrate thickness, interlayer temperature, and deposit height on the magnitude and distribution of residual stresses were investigated. Substrate thickness was found to have a major influence on the residual stress distribution along deposit height. Tensile residual stress up to the value of the material yield strength was present. The majority part of the deposit showed tensile stress while substrate showed compensating compressive residual stress. Lower interlayer temperature samples exhibited residual stresses of higher degree of magnitude compared with sample produced using higher interlayer temperature. Deposit height, i.e., total number of layers affected stress distribution pattern similar to substrate thickness.
Study on the Lubrication Characteristics of Spur Gear Pairs With Low Sliding Ratio Under Mixed Elastohydrodynamic Lubrication
Authors: Zhao Jiang , Sheng Wei , Li Zhengminqing , Zhang Hong , Zhu Rupeng 
Published: November 2021

Abstract
The relative sliding at the meshing point directly affects the contact and lubrication characteristics of the gear pair and is an important factor of gear wear and power loss. In this study, for investigation of a new type of low sliding ratio (LSR) gear pair whose tooth profile is constructed by a cubic function, a three-dimensional (3D) mixed elastohydrodynamic lubrication (EHL) line contact model was established with consideration of the effect of tooth profile geometry, transient motion characteristics, load distribution, and machining roughness. The distribution of the center film thickness of the LSR gear along the meshing line was predicted through an example the result of which was compared with a typical line contact EHL formula to verify the model. In addition, the difference was investigated in film thickness distribution of friction coefficient and temperature rise between LSR spur gears and involute spur gears. Hence, the effect of 3D rough tooth surface on the contact lubrication characteristics of LSR gears was discussed. The results demonstrated that the minimum center film thickness of the LSR gear appeared at the alternating point of the concave and convex tooth surfaces. At the same time, compared with the involute gear, the LSR gear significantly increased the film thickness at the start and ending points of the meshing and reduced the friction coefficient and the flash temperature rise.
Piezoelectric Actuator Performance Metrics and Relation to Compliant Mechanism Design
Authors: Maddisetty Hima , Frecker Mary 
Published: November 2021

Abstract
Piezoceramic actuators have gained widespread use due to their desirable qualities of high force, high bandwidth, and high energy density. Compliant mechanisms can be designed for maximum stroke amplification of piezoceramic actuators using topology optimization. In this paper, the mechanical efficiency and other performance metrics of such compliant mechanism/actuator systems are studied. Various definitions of efficiency and other performance metrics of actuators with amplification mechanisms from the literature are reviewed. These metrics are then applied to two compliant mechanism example problems and the effect of the stiffness of the external load is investigated.
Experimental Investigations on Oil Accumulation Characteristics in a Vertical Suction Line
Authors: Lee Jun-Pyo , Hwang Yunho , Radermacher Reinhard , Mehendale Sunil S. 
Published: November 2021

Abstract
A small fraction of oil circulates in refrigeration and air-conditioning systems. Oil return from the compressor discharge to the compressor suction is an important requirement for ensuring the reliability of the compressor. Oil return characteristics are affected by refrigerant/lubricant mixture properties, gas velocities, and piping geometry. In refrigeration systems, the oil film in vertical upward flow is hard to push upward since the refrigerant has to overcome the gravitational force and viscous force. The worst conditions hindering reliable oil return are the immiscible pairs of the refrigerant and oil when flowing from the evaporator to the compressor suction through the vertical upward tube because of their relatively high viscosity. This paper presents experimental results of the oil accumulation characteristics of R-134a and three oil mixtures in a vertical upward suction line by measuring the oil accumulation, and by visualizing the flow pattern. The test facility, which allows one to vary refrigerant/oil flow rates in a wide range and observe flow patterns, has been built. The amount of oil accumulated in the suction line was measured by the oil injection and extraction method. The flow visualization shows that oil films flow either by chum flow or annular flow, depending on the refrigerant flow rate. Mineral oil and other high viscosity oils result in larger oil accumulation and higher mean oil film thickness ratio in the suction line than in conventional oils. This paper reports the current status of a longer-range effort to develop a verified model for oil retention in vapor compression systems.
Analysis of Bending Behavior of Native Auricular and Costal Cartilage and Tissue Engineered Constructs
Authors: Roy Rani , Kohles Sean S. , Zaporojan Victor , Bonassar Lawrence 
Published: November 2021

Abstract
The current literature presents many techniques for analysis of the mechanical properties of articular cartilage [1]. By comparison few techniques are available for analysis of auricular cartilage which experiences a different mechanical environment than articular cartilage. Specifically, large deflection bending is a deformation mode that is most relevant to auricular cartilage, but has not been studied thoroughly in soft tissues. The goals of this study were to: 1) apply an elasticity model to three point bending data from normal and engineered auricular and costal cartilage; and 2) use this model to determine the tensile elastic moduli.
Secondary Flow and Wall Shear Stress in Three-Dimensional Steady Flow AAA Hemodynamics
Authors: Finol Ender A. , Amon Cristina H. 
Published: November 2021

Abstract
Abdominal Aortic Aneurysms (AAAs) are balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. The mean age of patients with AAA is 67 years and males are affected more often than women in a ratio of 4:1. Abdominal aortic aneurysm rupture is the 13th leading cause of death in the United States, affecting 1 in 250 individuals greater than 50 years of age. AAAs usually remain asymptomatic while slowly enlarging over a period of years or even decades. Factors that are known to affect the risk of aneurysm rupture are: maximum transverse dimension of the aneurysm, its expansion rate, its relative size compared to the patient’s body size, smoking, and family history of the patient. The five-year survival rate is only 19% and the overall mortality rate following rupture may exceed 90% [1]. Therefore, aneurysm screening and determination of the factors that may have an important role in aneurysm growth and rupture have become important elements in the investigation of this clinical problem.
Mathematical Modeling of Normal, Degenerated, and Fused Cervical Spines Using IAR’S Concept
Authors: Meghdari Ali , Bahrami Amir H. 
Published: November 2021

Abstract
During flexion/extension, of the head-neck system, cervical spine undergoes a stepwise motion from the upper to lower regions with a specific time lag. Motion of each vertebrae is composed of a translation and a rotation with respect to lower vertebrae, which may be considered as an absolute rotation about an axis called Instantaneous Axis of Rotation (IAR). Location of this axis is different between normal, and degenerated spines. In this research intersegmental force-moments are evaluated and compared in normal, degenerated, and fused subjects employing a biomechanical model of head-neck system based on IAR’s concept and the results are presented.
Decision-Based Design of a Wearable Low Vision Aid
Authors: Seibel Eric J. , Frank Samuel S. , Kloeckner Kyle W. , Furness Thomas A. 
Published: November 2021

Abstract
The design of a wearable low vision aid (WLVA) encompasses a wide range of design variables and made more complex by rapidly changing camera, micro-display, and computer technologies, and with the unique needs of the partially sighted user. Many of the WLVA design challenges have been documented by Massof [1] using miniature cathode ray tube (CRT) displays. Our goal.is to develop new scanning light micro-displays for low-cost WLVAs. Originally proposed by Peli [2], we are designing WLVAs that scan light from a laser or light emitting diode (LED), directly toward the eye. As the light beam raster scans across the retina, the mind perceives it as a full image. This display technology is called retinal light scanning, which produces images of high brightness from the laser or LED source and great depth-of-focus because of the narrow beam of light. A recent reading performance study demonstrated significantly higher reading rates of a minority of partially sighted individuals using a retinal scanning Virtual Retinal Display (VRD) versus a CRT [3]. We are in the process of researching low-cost optical scanners [4], novel human interface designs [5], and a computer-aided, decision-based design process to aid in the development of WLVAs. The initial results from our computer-aided design process are presented here.
A Mathematical Model for the Flow of Blood Through Arteries
Authors: Vasudevan Venkatesh 
Published: November 2021

Abstract
Scientists have for long been attempting to put forth a mathematical model which could explain the flow of blood through arteries. The study of flow through rubes began as early as in 1839 with the volume flow rate equations put forth by Hagen. Another formulation was suggested by Poiseuille, which resulted in the Poiseuille’s law of Fluid Flow through circular tubes. Rubinow & Keller incorporated the elastic nature of the tubes in their paper of 1971 wherein an equation for the flow of a Newtonian fluid through an elastic tube was developed. Mazumdar generalized the model proposed by Rubinow & Keller for Non Newtonian flow. Though the above models can be made use of to study the flow of blood through arteries after several simplifying assumptions, a realistic mathematical model must necessarily account for various anomalous properties exhibited by blood. This paper puts forth a model, which incorporates experimentally observed, atypical behavior demonstrated by blood under special conditions of flow. The model is then shown to be a generalized case of the models put forth previously.
Application of High Resolution PIV Processing in Flow Through Mechanical Heart Valve
Authors: Subramanian Amirthaganesh , Yee Lauren K. , Kadambi Jaikrishnan R. , Wernet Mark P. , Harasaki Hiroaki 
Published: November 2021

Abstract
Particle image velocimetry (PIV) processing techniques, Multi Pass Correlation (MPC) and Particle Tracking Velocimetry (PTV), are applied to images obtained from a bileaflet mechanical heart valve study to obtain velocity measurements with increased spatial resolution and accuracy. Using subregions of 32 pixels by 64 pixels, a spatial resolution of 0.23 mm in x and 0.46 mm in y is obtained, as compared to 0.46 mm in both directions for traditional PIV processing. When MPC and PTV are not utilized, spatial resolution can only be increased by decreasing the subregion size and time between images in an image pair, which sacrifices accuracy. High accuracy can only be obtained by increasing the subregion size and the time between pulses, which reduces spatial resolution. MPC and PTV allow both high spatial resolution and accuracy by altering the processing method as opposed to how the data is produced conventionally.
Evaluation of Bond Strength With Void Subjected to Harmonic Peeling Loads
Authors: Vaziri A. , Hamidzadeh H. R. , Nayeb-Hashemi H. 
Published: November 2021

Abstract
Joining components by using adhesives is becoming more popular with the development of adhesives with high adhesion properties. These components are often subjected to dynamic loading, which may cause initiation and propagation of failure in the joint. In order to ensure the reliability of these structures, their dynamic response and its variation with the presence of defects in the bonded area, must be understood.
Dynamic response of a single lap joint subjected to an out of plane harmonic force is evaluated. The bonded joint is modeled as Euler Bernoulli beams, joined with an adhesive and constrained at one end and subjected to a harmonic force at the free end. The results show that the system response is not sensitive to a range of adhesive loss factor of 0-1. Furthermore, the system response is little affected by the presence of void in the bond area. The system response seems to be more sensitive to the void location than to its size.
Peel and shear stress in bond area are obtained and found to be confined to the edge of the overlap. For adhesive and adherents properties and geometry investigated the maximum peel and shear stress in the bond area are little affected with the presence of a central void which covers less than 60% of the over lap length for all range of frequency. However, when the frequency of the applied load is close to the natural frequency of the structure, a void increases both maximum peel and shear stress.
A Tutorial on Present and Future Global Approximation Issues With Application to a Vehicle Design Problem
Authors: Miano Carlo M. , Gobbi Massimiliano , Mastinu Giampiero 
Published: November 2021

Abstract
A tutorial is presented on Global Approximation, a mathematical procedure useful for the optimisation of complex systems. The state-of-the art numerical algorithms that can be exploited within a Global Approximation approach are reviewed. Some original numerical procedures are also proposed, such as using Low Discrepancy Sequences to train Multilayer Perceptron Neural Network (MLPNN) or Radial Basis Function Neural Network (RBFNN). The final aim of the research is to find a mathematical algorithm for Global Approximation which requires a minimum of expertise to be effectively used. A number of candidate algorithms for such a kind of Global Approximation are comparatively tested with reference to a vehicle design optimisation problem. The result is that the RBFNN can be as efficient as the MLPNN, which is much harder to train, when used to find a satisfactory approximation of the relationships among design variables and objective functions which define the road holding and handling performance of a race car. It is envisaged that in the future Global Approximation could be used to derive the relationship between Pareto-optimal design variable values and Pareto-optimal objective function values.
Modular Structural Component Design Using the First Order Analysis and Decomposition-Based Assembly Synthesis
Authors: Cetin Onur L. , Saitou Kazuhiro , Nishigaki Hidekazu , Nishiwaki Shinji , Amago Tatsuyuki , Kikuchi Noboru 
Published: November 2021

Abstract
This paper discusses an automated method for designing modular components that can be shared within multiple structural products, such as automotive bodies for sibling vehicles. The method is an extension of the concept of decomposition-based assembly synthesis. A beam-based topology optimization method, originally developed for First Order Analysis (FOA) of the automotive body structures, is utilized in order to obtain the “base” structures subject to decomposition. It is expected that the method will facilitate the early decisions on module geometry in automotive body structures, by enhancing the capability of the FOA system. Several case studies with two-dimensional structures are reported to demonstrate the effectiveness of the proposed method. The results indicate that two structures optimized for a similar, but slightly different boundary loading conditions are successfully decomposed to contain a component that can be shared by the structures. Several Pareto optimal decompositions are presented to illustrate the trade-offs among multiple decomposition criteria, with different weights for each objective function.
Flow Reversal in Laminar Mixed Convection
Authors: Behzadmehr A. , Galanis N. , Laneville A. 
Published: November 2021

Abstract
Mixed convection of an air flow in a uniformly heated vertical tube was studied with a numerical model based on the three dimensional elliptic conservation equations and the Launder and Sharma low Reynolds number K-ε turbulence model. For Re = 1000 and three different Grashof numbers two patterns of flow reversal were predicted. The first one, for a moderate Grashof number, occurs at the centerline region and the second, for a high Grashof number, appears between the centerline region and the wall.
Numerical Analysis on the Dropwise Condensation of a Binary Vapor Mixture
Authors: Akiyama Hirokuni , Nagasaki Takao , Ito Yutaka 
Published: November 2021

Abstract
A numerical simulation was performed on the condensation of water and ethanol vapor mixture on a horizontal wall in a plane two-dimensional field. The analysis solves unsteady flow and heat-and-mass transfer both for liquid and vapor with the phase equilibrium condition at the interface, using FDM and boundary-fitted coordinates to track the deformation of interface. The calculation was started from a very thin smooth liquid film, and it was found that instability occurs when the film thickness reaches a certain value resulting in the formation of relatively small droplets. With the growth of the droplets, they coalesce into larger ones. Between the droplets an extremely thin liquid film exists, and the surface tension gradient sustains the droplets. With the increase of the wall subcooling the maximum droplet becomes large due to the increase of the Marangoni effect.
Modeling of Flow Characteristic and Heat Transfer for Micro Couette Flow
Authors: Xue Hong , Xie Ling , Chou S. K. 
Published: November 2021

Abstract
Gaseous flow encountered in micro/nano electromechanical systems experiences change in Kn number across a wide range of flow regime due to variation in characteristic length in the system and significant compressibility of the rarefied gas. In this study, we attempt to develop a general, physics-based model to predict the flow and heat transfer in the slip and transition regimes. Such an extension is constructed on the fact that Chapman-Enskog’s approximation of the Boltzmann equation can be revised using a function of Kn number as a perturbation. Velocity slip and temperature jump at the solid boundaries are modified accordingly. Rarefaction effects on dynamic viscosity and thermal conductivity are considered. As a first step to evaluate the model, it is applied to the simplest shear-driven flow, micro Couette flow. Compared with the results of DSMC, satisfactory agreement has been achieved in a wide range of Kn and Ma numbers.
Predicting Flow Boiling Heat Transfer of CO2 in Microchannels
Authors: Zhao Yuan , Ohadi Michael M. , Molki Majid 
Published: November 2021

Abstract
Microchannels have been widely used by the refrigeration/air conditioning industry. Zhao et al. (2000a,b) presented their experimental results for CO2 flow boiling in microchannels. In the present study, empirical modeling is performed to correlate the experimental data. Five state-of-the-art, large-tube empirical models are compared with the experimental data. It is found that these correlations fail to satisfactorily predict the experimental data for microchannels. This indicates that the heat transfer behavior in microchannels is different from that in large channels. A new correlation is developed based on Liu and Winterton’s correlation by introducing confinement factor to account for the micro-scale effects. The new model agrees well with the experimental results for CO2 flow boiling in microchannels within ±20%.
Effects of Friction and Cutting Speed on Cutting Force
Authors: Marusich Troy D. 
Published: November 2021

Abstract
Observations are made regarding the influence of cutting speed and friction on cutting force by way of finite element modeling. Simulations are validated by comparison of cutting forces and chip morphologies for the A16061-T6. Analysis of cutting forces over a wide range of cutting conditions suggests an important role of the secondary shear zone in the decrease of cutting force as a function of speed, even well into what is considered to be the adiabatic machining regime. The proposition is supported by a decrease in chip thickness and significant increase in temperature at the tool-chip interface as the speed is increased. Temperatures in the primary shear zone rise only modestly and cannot account for the change in cutting force. Furthermore, the effect contributes to the nonlinear increase of forces with respect to feed as opposed to a plowing force by the cutting edge radius.
Manufacturing Engineering Education in the Context of Globalization
Authors: Swearengen J. C. , Subramanian K. (Subbu) 
Published: November 2021

Abstract
The purpose of this paper is to report on an industry Panel regarding manufacturing engineering education, and especially to examine the presentations for emerging requirements. The new competency most emphasized was preparation for globalization. The concept has not yet had widespread impact on undergraduate engineering curricula in general; manufacturing engineering is certainly no exception. The industry reports summarized here, combined with the literature on the subject should help educators draft objectives statements and measurable outcomes for manufacturing engineering education.
Two-Dimension Shape Measurement System for MEMS Using Micro-Fizeau Interferometer and its Applications
Authors: Arai Yasuhiko , Yokozeki Shunsuke , Aoyagi Seiji , Mori Astunobu 
Published: November 2021

Abstract
A new measurement technology for the mems field is proposed using optical measurement method. Furthermore, this measurement and computer simulation technologies are combined together in order to perform a measurement evaluation which has been never done before and which has been desired in mems fields. For example, the thermal deformation by a laser beam in the case of the dynamics measurement of a microstructure using an optical method influences a measurement field. That is, the optical measurement is already not a non-contact measurement in the mems fields. As shown here, there are such practical problems in the measurement of the mems field. Then, these problems have never been discussed before, because any measurernent method did not exist. These problems are going to be discussed in this paper. In order to avoid this problem as much as possible, a novel measurement technology is discussed and proposed in this paper. A new measurement system is constructed under this discussion. Furthermore, using this system, the physical phenomena in the mems field can be observed and discussed at the same time. That is, the shape of an object, the mechanical deformation of the object forced on the external forces, the stress in the object, and viscosity of air around the vibrating object are investigated.