bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design Optimization of Monoblade Autorotating Pods to Exhibit an Unconventional Descent Technique Using Glauert’s Modeling
Authors: Patnaik Shashwat , Kanishk  
Published: January 2022

Abstract
Many unconventional descent mechanisms are evolved in nature to maximize the dispersion of seeds to increase the population of floral species. The induced autorotation produces lift through asymmetrical weight distribution, increasing the fall duration and giving the seed extra time to get drifted away by the wind. The proposed bio-inspired concept was used to produce novel modern pods for various aerospace applications that require free-falling or controlled velocity descent in planetary or interplanetary missions without relying on traditional techniques such as propulsion-based descent and the use of parachutes. We provide an explanation for the design procedure and the functioning of a mono blade auto-rotating wing. An element-based computational method based on Glauert’s blade element momentum theory (BEMT) model was employed to estimate the geometry by maximizing the coefficient of power through MATLAB’s optimization toolbox using the Sequential quadratic programming (SQP) solver. The dynamic model was developed for the single-wing design through the MATLAB Simulink 6-DOF toolbox to carry out a free-flight simulation of the wing to verify its global stability.
The Effect of Membrane Topology on Separation Performance of Vacuum Membrane Distillation Module
Authors: Caspar Justin , Xue Guanyang , Krysko Robert , Oztekin Alparslan 
Published: January 2022

Abstract
2D Large Eddy Simulations (LES) were conducted to study the effect of channel geometry on the Vacuum Membrane Distillation process. The geometry was altered by imposing a sinusoidal (“wiggly”) wall profile. The results of the study show at a critical Reynolds number between 750 and 1,000, transient vortices appear in the channel. As the Reynolds number is increased from 1,000 to 1,500, the origin of the vortices moves further upstream, and the frequency and intensity of the vortex activity increase. Areas, where vortex shedding provides mixing, serve to enhance the performance of membrane distillation profoundly. The mixing reduces temperature and concentration polarization along the membrane surface. With better mixing provide at Reynolds number 1,500 versus 1,000, the difference in performance versus the corresponding flat sheet membrane case is increased. The vapor flux in the wiggly channel module increases 6% at Reynolds number 1,000 and 22% at Reynolds number 1,500 compared to the flat channel module. The change in flux is from 61.6 to 65.7 kg/m2/h at Reynolds number 1,000 and 66.5 to 81.4 kg/m2/h at Reynolds number 1,500. Temperature polarization was also mitigated at Reynolds number 1,500 even though the flux was increased.
A Comparative Analysis of Object Detection Algorithms in Naturalistic Driving Videos
Authors: Zhang Ce , Eskandarian Azim 
Published: January 2022

Abstract
Intelligent vehicle research has been rapidly developing. Object detection is one of the most critical study areas for intelligent vehicle’s driving safety. This paper conducts a comparative analysis for two popular real-time object detection algorithms: Yolo-v4 and deconvolutional single shot multibox detector (DSSD) under a naturalistic driving environment. An 80-classes COCO dataset trains each neural network at first, then fine-tuned by the BDD100k dataset. The detection results are compared by True/False Positive Results, Precision-Recall Curve, and average precision @ intersection of union 50 and average precision @ intersection of union 75 results. According to the analysis results, the Yolo-v4 outperforms the DSSD algorithm in bad weather, nighttime conditions, and small object detections. The Yolo-v4 and DSSD mean average precision for the BDD dataset is 22.63 and 11.86, respectively. The Yolo-v4 precision is 90.81% better than the DSSD algorithm, proving that the Yolo-v4 is a better fit for real-world driving environment studies.
A Parametric Study: Influence of Geometry and Material Properties on the Response of the Femoral Head Through Biofluid
Authors: Paliwal Manish 
Published: January 2022

Abstract
Friction-induced stick-slip phenomenon has been reported in 1–20% of patients with ceramic-on-ceramic total hip replacement. The friction behavior of the bearing surfaces is ruled by the lubrication conditions, which may be from hydrodynamic lubrication to mixed or boundary lubrication. In the latter two situations, surface-to-surface mechanical contact may give rise to the friction-induced stick-slip phenomenon. Essentially, stick-slip occurs when the film lubrication is broken. Stick-slip is an undesired phenomenon and is understood to give rise to the squeaking phenomenon in the hip bearing surfaces. In this study, the influence of the relative densities of biofluid, size, mass, and femoral head material is investigated to study the system’s response and the approach of the femoral head towards the acetabulum shell (initial contact to pre-swing phase). Two configurations were developed, which included ball-on-plane and ballon socket configurations. Utilizing parametric studies, the role of these variables was studied. Higher velocity-derived energy may contribute to the vibration of the system via stick-slip. High approach velocity combined with high-density material may influence and lead to surface-surface articulation.
Correlation Between Process Parameters and Fracture Property of 316L Stainless Steel Parts Fabricated by Selective Laser Melting
Authors: Jin Jianhang , Xie Zhuowen , Yang Guanghui , Jiang Wei 
Published: January 2022

Abstract
Compact tension (CT) specimens of 316L stainless steel (SS) were fabricated by selective laser melting (SLM) technology using different combination of process parameters, including laser power, scanning speed, layer thickness and scanning strategy. The correlation between these process parameters and fracture property was investigated by Taguchi experiment. Crack opening displacement (COD) of the specimens were measured by digital image correlation (DIC) method. Through the analysis of range (ANOR) and analysis of variance (ANOVA), the influence of process parameters on the fracture property of pre-cracked CT specimens was found in the order of laser power, layer thickness, scanning strategy and scanning speed. The load increases gradually under the same COD value with the increase of laser power, and with the reduction of scanning speed and layer thickness. Within the selected range of parameters, the fracture property was optimal at the process parameters with a laser power of 200W, a scanning speed of 500mm/s, a layer thickness of 0.03mm and a parallel scanning strategy. This paper may provide guidance for process parameter selection to improve fracture property of selective laser melted parts.
Climate Change and Global Warming - The Forgotten Factors
Authors: Conkol Gary K. 
Published: January 2022

Abstract
The recent global pandemic has provided an unparalleled opportunity to examine and potentially calibrate our responses to Global Warming. Since 1992 there has been much debate but also vast deployment of technology from satellites to atmospheric monitoring stations to study climate change and, specifically, global warming. Copious amounts of atmospheric temperature and Greenhouse Gas (GHG) data have been continuously recorded. Data throughout the 2019 pandemic to present, now provide the rare opportunity to test understanding of Global Warming and resulting Climate Change.
Herein, changes in temperature and Green House Gases with respect to the time, during which global activities shut down or were significantly decreased, are used to design a multi-faceted approach to further examine our understanding and actions relative to Global Warming. A combination of perturbation and sensitivity analysis are proposed to draw attention to short and long-term efforts that have the potential to help further understand and calibrate efforts to manage Global Warming. The primary focus is to utilize changes noted during the pandemic to inform calculations and global warming predictions and actions.
The Consistency of Helicopter ‘Ground Resonance’ and the Unstable Lateral-Torsional Vibration in Standard Rotor Systems
Authors: Qian Xin , Fan Yu , Li Lin , Wang Wenjun 
Published: January 2022

Abstract
Ground resonance is a specific unstable vibration caused by the modal coupling between the blades and fuselage of a helicopter structural system. On the other hand, the unstable vibration in a standard rotor model can also be triggered by lateral-torsional coupling. This paper studies the consistency of instability mechanisms between the ground resonance and the lateral-torsional coupling vibration. Based on the two-dimensional equivalent model of helicopter system, the critical elements leading to the ground resonance are firstly studied by modal analysis. Comparison between the ground resonance and the lateral-torsional coupling vibration is then performed in two aspects: critical elements causing instability in dynamic matrices and modal shapes in the modal coupling ranges. Results demonstrate that the instability mechanism of the ground resonance is consistent with which of the lateral-torsional coupling vibration. The reason why similar instability does not occur in the general rotor system with elastic supports is also clarified.
Effect of Die Velocity on Tube Deformation Mechanics During Low Pressure Tube Hydroforming Process Sequence Variation
Authors: Nikhare Chetan P. , Buddi Tanya , Kotkunde Nitin , Singh Swadesh Kumar 
Published: January 2022

Abstract
Tube hydroforming is one of the successful manufacturing processes to create a variety of shapes using fluid pressure. The process fills the tube with fluid and pressurizes it to deform in various cross-sections. The method is categorized in three types: high pressure, pressure sequencing and low-pressure tube hydroforming. Tube hydroforming has gained popularity due to its many advantages such as part consolidation, uniform deformation, quality of the formed part and the possibility of unique shapes with indents or angles. Due to uniform thinning in the formed part, the parts can be lower weight and thus proven to be the technology to create light-weight parts for automotive and aerospace industries to increase the fuel economy. This paper focuses on low-pressure tube hydroforming. In low-pressure tube hydroforming, during the closing of the die the tube is marginally pressurized to a fixed volume. The previous study which was published in IMECE2019 and 2020 was focused on to investigate the effect of variation of thickness on deformation mechanics of the tube with variation in the process sequence during low-pressure tube hydroforming. In this part of the research, the study focused on how the velocity of the die effect the deformation mechanics with variation of the process sequence during low-pressure tube hydroforming. The circular tube was formed in a square shape. The four sides of die edges were considered as individual edges and the motion of these edges will be varied to achieve the final shape. The deformation mechanics in each condition was presented and analyzed. The die velocity effect on die filling, thickness and strain distribution were studied. It was found that the die velocity effects the tube deformation for the thinner tube and buckling could be eliminated using low pressure with tight die filling.
UGV Localization With AI-Assisted EKF for Multi-Terrain Environments
Authors: Shaukat Salman Ali , Althani Thani , Anzil Mohammed Minhas , Ismail Hesham 
Published: January 2022

Abstract
Localization of Unmanned Ground Vehicle (UGV) in multi-terrain environments, specifically soft terrain, is challenging. High slip scenarios make localization a difficult task. The internal sensors of the UGV are highly dependent on the terrain structure and are prone to errors. Thus, an appropriate measure should be in place to address the mentioned challenges to achieve precise navigation of the UGV. To address this issue, we propose using the GNSS-RTK/IMU/odometer/optical flow-based EKF system to improve state estimation of the UGV and compare it with some legacy approaches. The ground-facing camera will be integrated with image processing techniques such as optical flow to get linear and angular velocities. Additionally, a convolutional neural network (CNN) is used to classify the terrain conditions and update the covariance matrices for the odometer in EKF accordingly.
Nonlinear Vibrations of Beams With Bilinear Hysteresis at Supports: Interpretation of Experimental Results
Authors: Balasubramanian Prabakaran , Franchini Giulio , Ferrari Giovanni , Painter Brian , Karazis Kostas , Amabili Marco 
Published: January 2022

Abstract
Several structures of important industrial relevance feature large-amplitude vibration, which can have an initially hardening or a softening behavior. Models with quadratic and cubic nonlinear stiffness terms are often used to predict the nonlinear dynamics of such structures. If boundary conditions constitute an important cause of nonlinearity, however, it may not be possible to describe the nonlinear behavior of these systems by means of these nonlinear terms. The bundles of fuel rods immersed in the coolant flow of pressurized water reactors constitute an important example of extreme softening behavior, which is not described accurately by the simple adoption of nonlinear stiffness terms proportional to the square and to the cube of displacement in the equation of motion. In fact, the spacer grids, which support the nuclear fuel rods inside the reactors, constitute nonlinear boundary conditions, and are responsible of the peculiar softening behavior. Dedicated experiments on the rotational constraint applied by the spacer grids were performed, revealing a softening stiffness, which conforms extremely well with a bilinear model with hysteresis, such as the one formulated by Caughey. Therefore, a single degree-of-freedom equation with bilinear stiffness terms was employed to model the large-amplitude vibrations of single and bundled fuel rods immersed in quiescent water, which were detailed by previous stepped-sine experiments. A viscous dissipative term was initially retained for modelling damping, since several sources of dissipation are present for fuel rods immersed in water, besides hysteresis at the spacer grid supports. A satisfying fit of the experimental frequency- and time-domain curves was achieved through the use of an optimization algorithm for the tuning of stiffness and damping terms. Viscous damping, however, is not constant during large-amplitude vibrations, but is amplitude-dependent. Therefore, the value of the relevant parameter had to be changed at each forcing level. The model was then refined by introducing four additional switch points for stiffness, besides the initial one. Moreover, a nonlinear damping term of the quadratic type, suitable for softening structures immersed in fluids, was included. The resulting equation of motion with a five-switch piecewise linear stiffness describes with improved accuracy the experimental results. Also, one set of damping parameters is capable of describing the experimental results in the entire forcing (vibration amplitude) range. All this clarifies that a simple multilinear stiffness model, with the inclusion of quadratic damping, can be successfully employed to describe the behavior of rods immersed in fluid, in presence of nonlinear boundary conditions introduced by spacer grids.
Analyzing Core Failure in Composite Sandwich Structures Using a Non-Local Anisotropic Damage Approach
Authors: Zhuang Linqi , Najafi Ali 
Published: January 2022

Abstract
In this work, a non-local anisotropic damage model is used to study the failure of Balsa core in a sandwich structure under various loading conditions. The adopted anisotropic damage model was developed to account for the anisotropic elastic response and degradation of the material for typical anisotropic materials. An implicit gradient enhance formulation was also derived to avoid singularities caused by local strain softening and thus realize a mesh-independent solution. To evaluate the capability of adopted damage model, two different scenarios are considered, one is a sandwich beam with Balsa core in 4-point bending and the other is a tapered sandwich beam subjected to uniaxial tension. For both cases, mesh independency using non-local damage model is verified, damage patterns and other related findings are also summarized.
Crushable Foam-Filled Cellular Core and Discrete Bonding: A Finite Element Study of Thin-Walled Cross Tube
Authors: Jenson Sean , Ali Muhammad 
Published: January 2022

Abstract
Automobile chassis are constantly being redesigned to improve crashworthiness and decrease overall weight to assist in increased fuel efficiency. Typically, thin-walled axial members such as rectangular and circular tubes are employed as energy absorbers in front and side collisions. These members are designed to absorb a maximum amount of energy in a short period of time by utilizing their collapse behaviors. During collapse, these axial crush tubes undergo progressive folding which exhibits moderate and relatively constant plateau stress regions as collapse occurs. This study is a continuation of the investigation into cross-shaped crush tubes and the addition of a composite graded cellular core addition. The cross shaped tube and graded cellular core have shown to have distinct deformation modes and behaviors under axial loading conditions. Additionally, the work presented here further investigates this structure through the addition of crushable foam material within the cell voids. This foam addition along with bonding techniques of the inner core to external tube structure assist in altering the crush behavior of the tubes while increasing stability and energy absorbing capacity of the structure. Numerical simulations were conducted in ABAQUS finite element software for cross tubes under axial impact loading conditions. Four cases were considered for the present study: no bonding, 3 bonding sites, 5 bonding sites, and 7 bonding sites. These cases were matched with the previous study results to determine the effects of crushable foam addition to the graded cellular core structure. The results show that the addition of crushable foam material to the cellular core structure further increases the stability of the structure and is less susceptible to Euler type buckling. The crushable foam improved structural strength and increased overall energy absorbing capacity. The results presented are a positive indicator of the potential to tune automobile chassis energy absorbers to significantly increase energy absorbing potential and alter the behavior of these members to perform favorably under axial impact loading conditions.
Development of a Contrived Tool Wear Method in Machining
Authors: Grimm Tyler J. , Potthoff Nils , Kharat Nilesh Ashok , Mears Laine , Wiederkehr Petra 
Published: January 2022

Abstract
Tool wear in machining is generally observed as early and late stage tool wear. During early stage tool wear, the tool is rapidly worn during a break-in period, followed by a stable region of tool wear. After machining more material, the tool reaches late stage tool wear. At this point, tool wear becomes unstable; tool failure occurs quickly or it may take some time. Therefore, late stage tool wear represents a bifurcation point, making it difficult to predict tool wear past this point.
Tool wear is well known to be stochastically influenced. Due to this effect, it is difficult to perform studies on late stage tool wear since machining tools will be affected differently up to this point, introducing unknown variables. A novel method is presented in this research which utilized artificial wear to reach late stage tool wear. This method, termed contrived tool wear, may be capable of reducing the stochastic tool wear that occurs during early stage tool wear. As an initial investigation, machining tool inserts were worn by taking several passes over a grinding wheel with the tool rotating in reverse. Several parameters were tested in an attempt to match the natural worn state as close as possible. Subsequent to artificial wear, the inserts were used to machine IN718. The presented method of contrived wear was found to be a good approach, but could not sufficiently replicate the tool wear typically produced in IN718 machining. Future work should aim at implementing a multi-axis approach to enable grinding at various angles to the rake face of the insert.
Experimental Performance Evaluation of Fixed-Geometry Hydrodynamic Thrust Bearings With Variable Taper Depths
Authors: Fais Collier , Ali Muhammad , Yasko Isaiah , Walker Rick , Lutfullaeva Anbara 
Published: January 2022

Abstract
This paper presents experimental performance characteristics of fixed-geometry hydrodynamic thrust bearings machined to different helical taper depths. Theoretical analysis based on the Reynold’s equation states that under favorable conditions, these taper depths can produce and maintain load-supporting hydrodynamic pressure yet result in characteristically different oil-film pressure distribution profiles and magnitudes of friction torque. These characteristic performance indicators have not previously been observed experimentally for unidirectional fixed-geometry hydrodynamic thrust bearings with helically tapered pads. An experimental test rig was developed by re-purposing a horizontal milling machine capable of subjecting the test bearings to speeds up to 1,265 rpm and axial loads up to 250 lbf (1,112 N). Under various combinations of constant speed, load, and lubrication supply conditions, the steady-state oil-film pressure distribution across the bearing pad and active friction torque are measured. The effects of variable taper-depth on hydrodynamic pressure distribution and friction torque are compared and discussed.
A Snapshot of the State of Biologically Inspired Design for Researchers, Practitioners, and Public
Authors: Jastrzembski Mia , Watson Bryan C. , Weissburg Marc J. , Bras Bert 
Published: January 2022

Abstract
Biologically Inspired Design implements natural features into technologies to improve performance. Given the success of Biologically Inspired Design we are interested in the research question: How is Biologically Inspired Design currently employed? Answering this question can help design the tools used to support Biologically Inspired Design, provide an understanding of the current “state of Biologically Inspired Design”, and identify where Biologically Inspired Design solutions have not been widely utilized. Identifying gaps in utilization could prompt investigation into Biologically Inspired Design methods in fields that have not incorporated this approach into their design methodology. To answer this research question, 540 Biologically Inspired Design examples was gathered equally from three data sources: Google Scholar, the Asknature.org “Innovations” database, and Google News. The data were coded across 5 categories and 42 sub-categories. The results of our coding provide insights into two areas. First, we identify subcategories that have been underexplored by Biologically Inspired Design. For example, 63% of the biomimicry examples were applications to physical artifacts and 82% of the examples impacted the usage phase of a product’s Life Cycle. Secondly, by comparing BID results between sources (news, scholarship, and practitioners) we have insight into mismatches between the three. This solution survey and analysis provides Biologically Inspired Design researchers and practitioners valuable insight into the current state of the field, with the goal of motivating future research, outreach, and application.