bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weighted Mori-Tanaka Approach for Homogenization of Particulate Composites at High Filler Fractions
Authors: Kabir Mobashar , Pervez Tasneem , Qamar Sayyad Zahid , Al-Jahwari Farooq K. S. 
Published: February 2024

Abstract
A thorough understanding of material properties allowed to tailor structures closer to their design specifications which then facilitated efficient lightweight products from transportation industry to the field of biomedical engineering. Our potential then to further optimize designs is contingent on our ability to more accurately predict effective properties of composites and is significantly important in products made of functionally graded composite materials that exhibit a gradual change in material properties along multiple directions. This research work proposes a new a simplified approach to determine effective properties of composites at high filler fractions using weight functions in conjunction with the Mori-Tanaka model. It is postulated that locally in any given particulate mixture of two materials, the composition based on local microstructure may either be defined as a filler of 1st material in a matrix of 2nd material or a filler of 2nd material in a matrix of 1st material i.e., reversing the role of constituents. The overall effective property is then obtained as a weighted sum of the two cases. Material properties predicted by the new approach lie strictly within the rigorous Hashin-Shtrikman-Walpole bounds. Predicted values for effective properties using the weighted Mori-Tanaka method yields good agreement with published experimental data, mainly at high filler volume fractions.
Modeling of Automotive Radar Sensor in Unreal Engine for Autonomous Vehicle Simulation
Authors: Rahi Adibuzzaman , Cardoza Chris Orlin , Vemulapalli Sri Sai Teja , Wasfy Tamer , Anwar Sohel 
Published: February 2024

Abstract
Accurately testing sensors used in vehicles prior to physical production is crucial for identifying potential shortcomings and configuring effective vehicle driver assistance systems and automations. The use of virtual environments for sensor simulation and testing offers extensive freedom and allows for experimentation with scenarios that are cost-prohibitive for physical testing. In this study, we developed a sensor model using the Unreal Engine to approximate the output of an actual Delphi ESR 2.5 medium-range radar. We utilized the LineBatcher function to create point clouds that simulate radar reflections and employed 3D grid based DBSCAN for object detection. Subsequently, we implemented centroid tracking to track objects and determine range rate, acceleration, and other outputs of the Delphi ESR Radar. In our test environment, the sensor performed close to identical to a Physical Delphi ESR 2.5 Radar with accuracy of 91% and at a data rate of 10–20 Hz.
Worldwide Lean Learning Factories
Authors: Witeck Gabriela R. , Alves Anabela C. 
Published: February 2024

Abstract
Lean production, also known as the Toyota Production System, is a management model that is being actively taught in academia through active learning methodologies. One such methodology is the use of learning factories to teach Lean concepts. Many Higher Education Institutions are promoting and installing learning factories to teach lean concepts effectively. This paper’s objectives are to discuss lean learning factories (LFF): characterization; importance for managers and organizations; lessons learned; lean learning aspects and general outcomes for life-long learning. To achieve this, the authors developed A literature review was conducted on lean learning factories, utilizing scientific articles obtained from the Scopus database. The review encompassed the period from 1990 to 2023. This literature review resulted in 95 papers, being the first articles relating to lean and learning factories published in 2006. The main findings revealed that the LLF can be found worldwide, and these initiatives were taken by universities and some involved organizations. Findings evidenced that setting up and installing one such LLF is not trivial and needs resources, but they contribute to the effectiveness of lean learning. The significance of these factories lies in their aim to replicate intricate real-world settings as accurately as possible, facilitating the best training in lean methodologies that align with the fundamental principles of Industry 4.0 and Industry 5.0.
Energy Absorbing Analysis and Deformation Modes of Crush Tube With Tapered Geometry
Authors: Jenson Sean , Ali Muhammad 
Published: February 2024

Abstract
Thin-walled axial crushing members, or crush tubes, are often utilized as energy absorbers due to their high strength to weight ratios. Applications of such devices include automotive, aerospace, and structural components. Core materials such as graded honeycomb or other support members have shown to greatly increase energy absorbing capacity, while improving structural stability during deformation or collapse. The ideal performance of such members through axial crushing exhibits numerous stepwise collapse mechanisms, or folding, up to complete exhaustion of the structure. The total capacity of these structures is highly dependent on the number of folds present during collapse. The present study aimed to improve upon previous axial crushing members with graded cellular cores through introduction of a tapered tube geometry. Optimization strategies included: decrease in component mass while meeting or exceeding previous energy absorbing performance. This study was conducted through a numerical approach using ABAQUS/Explicit dynamic modeling environment. Numerical analysis was performed until densification of the structure and numerical outputs were analyzed for crushing force, deformation modes, and total energy absorption. The tapered geometry of the tube and reduced mass of the tube/core presented a 21.3% weight reduction while maintaining similar energy absorbing performance to previous square tube configurations. The tapered tube geometry exhibited predictable stepwise collapse/fold initiation progressing from impact to distal end of tube. The overall weight reduction and predictable collapse pattern showed potential to increase customizability of crush tube members and provide additional optimization parameters.
Parametric Modeling of Lattice Structures for Manufacturing via Masked Stereolithography Apparatus
Authors: Sherwood Benjamin D. , Billings Christopher , Liu Yingtao 
Published: February 2024

Abstract
An investigation into parametric modeling of lattice structures is conducted in pursuit of an effective and efficient process for manufacturing lattice structures via masked stereolithography apparatus (MSLA). Principals of Design for Additive Manufacturing (DfAM) are applied, keeping in mind the manufacturing process to be used. Key design features are parameterized to decrease the effort required to design and implement changes to the structures. Unit cells are modeled as interconnected struts according to parameters such as unit cell side length and strut diameter or thickness. As well as parameterizing the unit cell geometry, the number of cells in each of the three cartesian directions are parameterized such that a three dimensional array of unit cells is constructed based on the single unit cell. Three unit cells are to be considered: the simple cubic (SC) unit cell, the body-centered cubic + simple cubic (BCC|SC) unit cell, and the face-centered cubic + simple cubic (FCC|SC) unit cell. A simple procedure for interfacing the lattice to bulk material is proposed. The proposed design process is validated through qualitative analysis of lattice samples designed with varying unit cell and overall lattice properties with results supporting future studies. Additionally, an example of replacing a solid model’s interior with the lattice structure is detailed to demonstrate the simplicity and power of the approach. It is found that even very thin features with maximum dimensions less than 10 pixels or layers depending on feature orientation (0.34mm and 0.5mm, respectively) are able to be manufactured using affordable consumer grade equipment, which allows for a multitude of potential applications from general purpose lightening to primitive object strength augmentation.
Variable Geometry Crush Tube With Induced Folding Mechanisms
Authors: Jenson Sean , Ali Muhammad 
Published: February 2024

Abstract
Thin-walled axial crushing members are employed as front energy absorbers in automobile chassis design. They improve crashworthiness while maintaining low structural weight addition due to their high strength to weight ratios. The addition of core material has also been shown to increase energy absorption capacity and structural stability during deformation. Specifically, the addition of functionally graded cellular cores maintained high strength to weight ratios and assisted the increase in strength and stability. The present study aimed to investigate the effects of induced folding of the outer tapered tube structure to maximize energy absorbing performance of the axial crush tube member. This study was conducted through a numerical approach utilizing ABAQUS/Explicit dynamic module. Numerical analysis was performed until densification/locking strain for each case. Analysis criteria included: crushing force, plateau stress, deformation modes and energy-deformation stroke plots. The induced structural collapse due to the peripheral cuts forced progressive folding in a more predictable pattern as compared to the standalone structure. It has been shown that energy absorption increases with the number of deformation sites and the induced folding mechanism assisted in maximizing this effect while following a predictable deformation behavior. The increased number of deformation sites due to the peripheral cuts resulted in a 10.1 % increase in mean crushing force and 14.6% increase in energy absorption as compared to the configuration without peripheral cut hence confirming potential for further improvement in energy absorption of thin-walled axial members.
Dielectric and Mechanical Characteristics of Polyamide-Silicon Dioxide Nanocomposites
Authors: Mahon Nicholas R. , Ericksen Jared , Lawton Sean F. , Coraggio Max P. , Terifay John P. , Smith Michael , Martinez-Castro Diana , Maienza Paul M. , Xue Wei 
Published: February 2024

Abstract
Nanocomposites have emerged as a promising area of research in recent decades due to their ability to improve the properties of host materials. Nanocomposites for cryogenic applications have gained significant attention for their potential in high-temperature superconducting (HTS) power transmission systems. However, exposure to low temperatures has detrimental effects on the material properties of the dielectrics, limiting their applications. This necessitates the investigation of thermally stable high-quality dielectrics, which can be quantified through electrical and tensile testing in various controlled environments. This paper discusses the preparation of a polyamide (PA) / SiO2 nanocomposite through a sol-gel process. The primary focus in this project is on the baseline material characteristics at room temperature. We have performed a multitude of microscopy imaging, AC and DC dielectric tests, and tensile tests, all under a room temperature environment. The results of this research can help improve the understanding of these composites and guide our future material testing in cryogenic environments.
Experimental Determination of Load-Carrying Capacity of Modified Tapered-Land Hydrodynamic Thrust Pad Bearings
Authors: Trammell Jenna , Fais Collier , Ali Muhammad , Walker Rick 
Published: February 2024

Abstract
In this study, a method for increasing specific load on hydrodynamic thrust bearings is introduced and experimentally evaluated. Experimental determination of thrust bearing load capacity is limited by the applied load capability of test equipment which may be unequipped to create specific load magnitudes for application-sized bearings. Theoretical analysis of Reynolds equation suggests there is a linear relationship between the number of pads on a thrust pad bearing and the maximum thrust load a bearing can support. Two bearing samples, one with 8 active thrust pads and the other with 4 similarly sized active thrust pads are fabricated and subjected to an experimental test matrix. Each bearing is tested at 20 different combinations of steady-state speed and thrust load all at consistent oil inlet conditions. Sensors integrated in the test rig measure the magnitude of hydrodynamic pressure acting on the middle of the thrust pads along with bearing temperature and minimum oil film thickness. Results from this study show that reduction of the active thrust bearing surface area by half was shown to increase the hydrodynamic pressure acting on the bearing by nearly 100%. Removing active thrust pads is proven to effectively multiply the specific load on the bearing pad and create a more extreme operating condition under lower thrust force without increasing the bearing size envelope and/or undergoing time consuming and costly test rig upgrades.
Computational Study on the Effect of Multiple Inlets in a Vacuum Membrane Distillation Module
Authors: Caspar Justin , Xue Guanyang , Oztekin Alparslan 
Published: February 2024

Abstract
2D Large Eddy Simulations (LES) were run to characterize the flow inside vacuum membrane distillation channels with multiple inlets. Jets are commonly used in industrial applications to induce mixing and disperse chemicals. For membrane distillation, multiple inlets provide a way to mitigate axial temperature polarization while promoting mixing in the channel. Four modules operating in the laminar regime, Reynolds number 750, were designed, two with inlets placed via fittings in the channel and two with inlets placed on the bottom wall of the channel. The injection was done through three inlets spaced evenly in a L/H 200 channel. The total injection flow rate was equal to the inlet flow rate. The jets were seen to reduce the impact of temperature and concentration polarization in the membrane module for the selected conditions by increasing the local Reynolds number and leading to a smaller boundary layer thickness. Injection through fittings saw flow separation in the channel at x/H of 150–200. The mixing structures, combined with the impact of the jet, lead to a 12% increase in flux performance. Without mixing, the jets contributed to a 6.5% flux increase.
Mobile Robot With Robotic Arm: Development and Validation of a Digital Twin
Authors: Salamina Laura , Gaidano Matteo , Melchiorre Matteo , Mauro Stefano 
Published: February 2024

Abstract
Mobile robots coupled with robotic arms are a powerful instrument for factory automation, and they have become more and more popular in last years. Their digital twins allow to simulate the behavior in an industrial environment, increasing the capability to monitor their performance to detect failures or deviation from expected behavior. This work considers a system composed by a MiR250 mobile robot and by a UR5 anthropomorphic robot and describes the digital twin of the composed system. The digital twin is the coupling of the model of the UR5 robotic arm and that of the mobile robot. The model of the mobile robot considers a dynamic model of each wheel, to investigate the behavior of driving and caster wheels, and the model of the motors, to evaluate the expected motor torque. The digital twin of the UR5 robotic arm was tuned according to an identification methodology previously developed. An experimental campaign was carried using an Optitrack motion capture system. The results show that the model can provide reliable data to check and forecast the behavior of the system. The paper describes the complete model of the system, discusses its identification process, and shows some results obtained in the experimental campaign.
Computational and Experimental Study on Effect of Increased Makeup Torque on Fatigue Life of Rotary Shouldered Connections
Authors: Song Fei , Du Michael , Li Ke 
Published: February 2024

Abstract
The tools and subs used on the bottom hole assembly (BHA) are threaded together by rotary shouldered connections. A rotary shouldered connection consists of a pin element and a box element has two main components: a seal/torque shoulder and threads. The rotary shouldered connection upon makeup needs to seal between internal and annular pressures at the shoulder and transmit torque, while withstanding the cyclic bending loads when drilling through a curved section of the well. If twist-offs occur on the connections, the drilling and measurement tools could be flooded with drilling mud invasion, causing severe damage of the expensive measurement devices and sensors, along with a significant amount of nonproductive time for fishing. With drilling becoming increasingly aggressive and challenging in recent years, the BHA can continue to torque up in the downhole. Rotary shouldered connections can be required to be made-up above the recommended torque values, such that uncontrolled downhole makeup in severe drilling environments could be prevented. With higher makeup torque, the fatigue resistance of the rotary shouldered connections would be compromised. Therefore, there is a strong need to understand the effect of increased makeup torque on the fatigue strength of the rotary shouldered connections.
In this paper, a computational model based on finite element analysis (FEA) of the threads is developed for predicting the bending fatigue life of the rotary shouldered connection under specific makeup torques. Specifically, the FEA model can capture the nonlinear interactions between the pin and box threads and on the seal face under combined loads of pretension and bending. Strain-life approach is used to assess the fatigue life of the connection under constant-amplitude cyclic bending based on the alternating strain and mean stress obtained from the FEA model. The developed FEA model is validated through comparison of the numerical predictions to the test results obtained from full-scale rotating bending fatigue tests of the rotary shouldered connections. Favorable agreement is found between the predicted fatigue strength of the connection and the experimental observations at various makeup torque values. Upon validation, the numerical modeling approach has been successfully utilized to virtually qualify the rotary shouldered connections of various types without conducting physical tests and to support operation in different drilling conditions, which has led to a tremendous amount of cost and time savings for rotary shouldered connection development and reduction in the cost of service delivery (COSD).
Thermal Performance of a Geothermal Source High-Temperature Heat Pump for District Heating – Comparison of Single-Stage and Cascade Vapor Compression Cycles
Authors: Dickinson Devon , Mai An , Govedaric Aleksandra , Shor Roman , Mwesigye Aggrey 
Published: February 2024

Abstract
Reducing greenhouse gas emissions is of utmost importance in the race to keep the global average temperature increase to within 1.5°C of pre-industrial levels to avoid catastrophic consequences of climate change. In cold climates, a large portion of carbon dioxide emissions come from the heating requirements of buildings, primarily space heating and hot water heating. Large institutional and commercial buildings use considerable amounts of energy to provide space heating and hot water, most of which comes from large-scale district heating systems powered by fossil fuels. There is therefore potential for emission reduction in institutional and commercial buildings using clean and renewable energy. This study investigates the use of high-temperature heat pumps in a high-temperature district heating system for a University Campus. The considered heat pump system meets 51 MWth of heating demand. The heat pump is coupled to a geothermal borehole 2 km in depth whose performance is modeled using CMG software for thermal reservoir modeling to improve its performance. The performance of the heat pump system using R134a is compared with that of environmentally friendly refrigerants, including R1233zd(E), R1366mzz(Z), R1234ze(Z), Butene, ammonia, R1224yd(Z), and RE245CB2. Results show that the cascade system yields higher average COPs regardless of the refrigerant due to lower compressor energy inputs. Results further show that using refrigerant R1233zd(E) in both system stages produces the best performance, with an average COP of approximately 3.0. Furthermore, for the building energy loads considered, high flow rates between 500 m3/h to 6000 m3/h are needed to meet the entire heating demand depending on the temperature difference between the inlet and outlet temperatures of the geothermal heat transfer fluid.
Solar Trackers Using Spherical Mechanisms
Authors: Sivarapu Aditya Krishna , Zhou Hong 
Published: February 2024

Abstract
The power harvesting from a solar panel is maximized when its face is perpendicular to the solar ray. In order for a solar panel to face the sun during the daytime, its orientation has to be adjusted by a solar tracker. There are two relative motions between earth and sun. Compared with its daily east to west rotation, sun’s south-north movement is much smaller. If only sun’s east-west relative motion is considered for developing solar trackers, mechanisms with single degree of freedom can be adopted. If the orientation of a solar tracker with single degree of freedom is adjusted seasonally or monthly to cover sun’s small south-north relative movement, the solar tracker can effectively fulfill its solar tracking function. Single-axis solar trackers commonly consume less power to operate than their two-axis counterparts and cost less to fabricate and maintain, which brings their solar tracking merits. This research is on single-axis solar tracking mechanisms that are based on four-bar mechanisms. Because of their simple structure, high reliability, and easy maintenance, four-bar mechanisms have been extensively employed for various applications that include solar tracking. Four-bar solar tracking mechanisms currently have room for further improvement. The difficulties facing them include limited solar tracking motion, high solar tracking power consumption, and lacking self-locking function. Surmounting these difficulties makes designing four-bar solar tracking mechanisms challenging. Four-bar solar tracking mechanisms can be planar 4R, planar 3R1P, spherical four-bar mechanisms. Each of the three types has its unique solar tracking features. In this research, the performances of these four-bar solar tracking mechanisms are analyzed, simulated and compared with the motivation of improving them. The research results are tried to provide some guidelines for developing and promoting four-bar solar trackers.