bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulation of a Canadian Well With One Circumferential Row of Internal Vortex Generators
Authors: Kharoua Nabil , Semmari Hamza , Haroun Mehdi , Korichi Houssem , Islam Md 
Published: September 2022

Abstract
Canadian wells are used for heating and cooling in residential buildings, agriculture and industry. They rely on the quasi-stable underground temperature at a certain depth throughout the year. One way to enhance the performance of this type of heat exchangers, is to implement internal Vortex Generators (VGs). The VGs contribute in disrupting the thermal boundary layer, intensifying turbulence and increasing the heat transfer coefficient.
Series of numerical simulations, using ANSYS FLUENT, were conducted to mimic the variable seasonal operational conditions of Canadian Wells during the year. One circumferential row of parallelepiped Vortex Generators was implemented in a real U-shaped tube Canadian Well geometry. The yearly ground and underground temperatures were implemented as sinusoidal functions of time and depth. The VGs were placed immediately downstream of the first bend close to the inlet. The Reynolds number was in the range 14975–42785. The ambient conditions were considered for the city of Constantine (Algeria) at an altitude of 600m over the sea level.
The VGs yielded an improvement of up to 8% of the heat transfer coefficient for different Reynolds numbers. The bend, upstream of the VGs, and the wake, downstream of them, play a key role in affecting the heat transfer locally.
Numerical Investigation of a Rotating Double Compression Ramp Intake
Authors: Margha Lubna , Hamada Ahmed A. , Ahmed Othman , Eltaweel Ahmed 
Published: September 2022

Abstract
The intakes of air-breathing high-speed flying vehicles produce a large share of the thrust propulsion. Furthermore, the propulsion performance of these engines increases when the single ramp intake is replaced with a multiple-ramps intake. Many scholars numerically and experimentally studied the high-speed engine performance over static single and multiple compression ramps. However, the transient behavior of the flow during the rotation of the double compression ramp from a single ramp is not fully investigated. The present paper aims to numerically investigate the transient shock reflection phenomenon over a rotating double wedge. The problem will start with a 3-Mach number inviscid flow over a single wedge. Then, a portion of the wedge will be rotated upstream at a quite low trailing Mach number to avoid the significant lag effect in the shock waves system. This idea could be applied in the supersonic intake or extensionally in the hypersonic intake of scramjets with a somehow complex mechanism. Further, the length of the rotating portion of the wedge will be changed three times to study its effect on the shock system. The results show a high gain in the pressure due to the rotation of the wedge. Moreover, the wave angles were larger at the low chord ratio value of w2/wi = 0.25 than at the high values of w2/wi at the same second wedge rotating angle, θ2, resulting in a higher pressure distribution.
Aerodynamic Analysis of the Utility Truck With the Morphing Boom Equipment
Authors: Patel Parth Y. , Jannoi Thannathorn , Zou Wenhui , Vantsevich Vladimir , Koomullil Roy 
Published: September 2022

Abstract
Global climate change has affected the human race for decades. As a result, severe weather changes and more substantial hurricane impact have become a typical scenario. Utility trucks with the morphing boom equipment are the first responders to access these disaster areas in bad weather conditions and restore the damages caused by the disaster. The stability of the utility trucks while driving in a heavy wind scenario is an essential aspect for the safety of the rescue crew, and aerodynamic forces caused by the wind flow constitute a significant factor that influences the stability of the utility truck. In this paper, the aerodynamic performance of the utility truck is modeled using the incompressible unsteady Reynolds Averaged Navier Stokes (URANS) model. The Ahmed body, a well-recognized benchmark test case used by the computational fluid dynamics (CFD) community for the aerodynamic model validation of automobiles, is used to validate this aerodynamic model. The validated aerodynamic model investigates the impact of heavy wind on the utility truck with the morphing boom equipment. The visualization of the flow field around the utility truck with the force and moment coefficients at various side slip angles are presented in this paper.
Joining of Metal-Thermoplastic-Tube-Joints by Hydraulic Expansion
Authors: Weber Florian , Lehmenkühler Peter , Hahn Marlon , Tekkaya A. Erman 
Published: September 2022

Abstract
To encounter current issues regarding climate change, the hybridization of structures with lighter, often dissimilar, materials is an essential cornerstone of lightweight design. The different mechanical behavior of these materials results in challenges in terms of joining. This paper utilizes the joining process by hydraulic expansion to manufacture tube-to-tube joints of aluminum alloy AA6060 T66 and thermoplastic polycarbonate (Lexan) at room temperature. In contrast to metals, elastic and plastic strains coexist in thermoplastics from the beginning of deformation. Based on the theory of linear elasticity, an equation was derived to calculate the fluid pressure that expands the polycarbonate up to a strain value where plastic strains start to increase significantly in comparison to elastic strains. Tensile tests of the joined tubes revealed that the transferable tensile load increased approximately exponentially with increasing plastic deformation of the polycarbonate. With ongoing plastic deformation, micro-cracks appeared and merged within the thermoplastic. The appearance of these so-called crazes had no negative influence on the transferable load within the range of applied fluid pressure.
One-Step 3D Printed Layers Along With xy-in Plane Directions for Enhanced Multifunctional Nanocomposites
Authors: Ravichandran Dharneedar , Song Kenan 
Published: September 2022

Abstract
Composite and hybrid materials displaying layered structures have broad applications in structural composites, fire retardant barriers, tissue scaffolds, and microelectronics. Inspired by biosystems, in this study, we explore the invention of a new 3D printing principle that can produce layered structures similar to those in trees, overcoming the bottleneck in additive manufacturing to include multi-materials. We use polyvinyl alcohol (PVA) and carbon nanotubes (CNTs) as material examples for producing alternating layers. With the unique 3D printing platform, Multiphase Direct Ink Writing (MDIW), the optimized dispersion quality and rheology behaviors allow the number of layers within an individual printing line to change between 4 and 512 layers. The mechanical tests consistently increased young’s modulus and ultimate tensile strength with decreased layer thickness and dispersion quality. The best-performed composites have 128 layers in one printing line, beyond which the dispersion of CNTs deteriorated due to aggregates. Due to the thin layer thickness, the improved composite mechanics relate to the closely packed CNTs and their alignment.
Moreover, we will also demonstrate this MDIW printing with different polymers (e.g., thermoplastic urethane and polylactic acid) and nanoparticles (e.g., iron oxide, carbon fibers) for mechanical enhancement and intelligent behaviors. This research demonstrated one new 3D printing method, MDIW, that can fabricate multilayered composites containing well-managed content in each layer. Our advanced manufacturing method is compatible with other materials and has potential use in batteries, supercapacitors, solar cells, regenerative medicine, and energetic systems requiring layered structures.
Characterization of Polylactic Acid Filament With Biodegradable Hemp Fiber Infused During Additive Manufacturing Process
Authors: Hanson Matthew , Yang Che-Hao 
Published: September 2022

Abstract
Fused Filament Fabrication (FFF) is one of the common methods among the Additive Manufacturing (AM) processes. In this study, hemp fiber, a sustainable, and fast degraded material introduced and mixed with fresh Polylactic Acid (PLA) filament with 3 wt%, 7.5 wt%, and 10 wt% to improve the drawbacks of pure PLA filament and sustain its required properties. The results from the fatigue testing of pure PLA, and various hemp-fiber infused PLA indicated that increasing the wt% content of a hemp fiber infused PLA specimen at a certain point does increase the ultimate bending stress as well as the overall fatigue life of a pure PLA specimen. The 10 wt% hemp fiber specimens provided a 7.32% increase in the mean ultimate flexural strength over pure PLA. The mean of Young’s modulus also increased by 10.65% for the 10 wt% hemp fiber specimen and by 23.05% for the 7.5 wt% hemp fiber specimen over PLA. The 10 wt% hemp fiber specimens also provided a 4.05% increase in fatigue life over PLA. The 3 wt% did not provide a significant improvement in the study. These findings provide insight into the AM processes and lead to the development of environment-friendly composites in the industries.
Micro-Architected Lattice-Based Mesh for Fiber Filters: A Novel Additive Manufacturing Architecture for Molded Fiber Tooling
Authors: Dominguez Jose , Gonzalez Paloma 
Published: September 2022

Abstract
Promising developments have shown the untapped potential of additive manufacturing (AM) for fabricating molded fiber molds (MFM), a critical piece for the molded fiber industry. This work builds upon AM implementations, presenting a novel application of micro-architected lattice structure to construct fiber filtering meshes attached to drainage channels, all combined in an “Integrated Mold.” Current AM approaches have failed to build low-cost and high lifespan tools. Instead, their design approach imitates the existing MFM structure, covering a base-shaped structure with a mesh. The main disadvantage of this method is the trade-off between water drainage and stiffness.
Lattice materials have shown the capability of building porous structures with high stiffness, strength-to-weight ratio, fatigue tolerance, and the capacity to control the flow of fluids. The methodology presented in this research defines a new approach for MFM design that provides a broader range of porosity and enhances water drainage capabilities without affecting structural performance. As a result, it retrieves enhanced control over the physical properties of MFM.
The studies presented in this paper show the functionality of lattice structures as filters for solid particles. Moreover, it offers an immediate application of this technology. The tools developed in this research have validated their capability to withstand more than a hundred cycles as tooling for MFP, proving their functionality for prototyping stages. This result seeks to accelerate the expansion of an industry that capitalizes on locally abundant, biodegradable, and recyclable raw materials.
Support Vector Machines for Classification of Direct Energy Deposition Standoff Distance for Improved Process Control
Authors: Alexander Zoe , DeVol Nathan , Emig Molly , Saleeby Kyle , Feldhausen Thomas , Kurfess Thomas , Fu Katherine , Saldana Christopher 
Published: September 2022

Abstract
A critical factor in the implementation of direct energy deposition is the ability to maintain the standoff distance between the nozzle and the build surface, as this influences powder capture efficiency and overall part quality. Due to process-related variations, layer height may vary, causing unintended variation in standoff distance and poor build quality. While prior work has utilized contact probing to qualify standoff distance during processing, in situ methods for qualification of standoff distance are of major interest. The present work seeks to understand efficacy of image-based methods for classifying standoff distance variation in real-time using support vector machines (SVMs). It was hypothesized that the size of the melt pool and the amount of spatter will have significant correlations with deviations in the standoff distance; thus, SVMs were used on a dataset that is comprised of morphological features of melt pool size and image entropy. The SVM model was used to classify melt pool images into categories according to standoff distance variation from nominal. K-folds cross validation was used to find the optimal hyperparameters for the SVM model. To understand the impact of the selected features on the classification performance and inference speed, multiple models were trained with differing numbers of included features. Results for classification score, inference time, and image preprocessing/feature extraction from these data are reported. The present results show that the SVM model was able to predict the standoff distance classification with an accuracy of 97 percent and a speed of 0.122 s per image, making it a viable solution for real-time control of standoff distance.
Mechanical Profile and 3D Printability of Cellular Structures
Authors: Rastegarzadeh Sina , Muthusamy Samuel , Huang Jida 
Published: September 2022

Abstract
Microstructures are critical elements for mechanical metamaterials design and fabrication. Tailoring the internal microscale structural pattern can achieve a much broader range of bulk properties than the constituent materials, thus enabling the metamaterial design with extraordinary properties. Studying the mechanical properties and fabricability of microstructures is critical for understanding metamaterials’ structural design and macroscale performances. This paper categorizes the commonly designed microstructures into two main classes: deterministic implicit function-based and stochastic nature-based designing strategies. The mechanical properties and 3D printability of typical instances within the two classes are studied and experimentally analyzed. Specifically, we investigate the macroscale mechanical properties (e.g., Young’s modulus, shear modulus, bulk modulus, percentage of anisotropy) of microstructures defined with triply periodic minimal surfaces (TPMS), Fourier series-based functions (FSFs), Gaussian random filed-based (GRF), and Voronoi-based microstructures. Asymptotic homogenization is exploited herein to study the macroscale properties of different microstructures, and the manufacturability of the structures is experimentally analyzed and validated on an FDM printer. We summarize the mechanical profiles and manufacturability of these microstructures defined by various principles. The resulting mechanical profiles and manufacturability of microstructures provide a reasonable basis for establishing a microstructure database and shed light on the on-demand structural units generation for metamaterial design and fabrication.
Roll to Roll Manufacturing and In-Line Imaging and Characterization of Functional Films
Authors: Glassmaker Nicholas , Mi Ye , Cakmak Mukerrem , Shakouri Ali 
Published: September 2022

Abstract
Roll-to-roll manufacturing is a promising platform to produce low cost, high quality electrical components and sensors for Internet of Things (IoT) applications. Within the roll-to-roll laboratories at Purdue University, a range of processes and machines have been developed to: 1) print patterns of conductive and sensing materials for use in electronic sensors, 2) cast films precisely with integrated functional materials, and 3) monitor quality of the printing and casting processes in-line in real time. A major development is the custom-designed and built Maxwell coating machine, which has enabled substantial quality improvements in slot-die coatings, as demonstrated by precise in-line thickness monitoring and imaging. As an illustrative example, we will show how we converted a design for a printed ion-selective electrode from a batch process to a roll-to-roll process. In-line process monitoring of coating thickness allowed us to identify high variability in the coating thickness due to an interaction between underlying printed electrodes and the drying process. By modifying the drying process, we demonstrated a substantial improvement as evidenced by the same in-line measurement technique. The overall process integrates several existing machines and processes in a novel way to create functional parts continuously, with data on individual parts gathered in real time.
Polymer Filament Extrusion Using LDPE Waste Polymer: Effect of Processing Temperature
Authors: Devra Rajdeep Singh , Srivastava Nishkarsh , Vadali Madhu , Arora Amit 
Published: September 2022

Abstract
Low-density polyethylene (LDPE) is a soft thermoplastic with extensive application as a packing material such as plastic bags, dispensing bottles, milk pouches, etc. Many LDPE bags are used and dumped in landfills every year, leading to millions of tons of persistent waste. In addition, the recycling of LDPE is of no commercial interest due to its low stiffness, poor mechanical properties, and limited commercial application. In the current work, we attempt to recycle milk pouches made of LDPE to create polymer filaments for fused deposition modeling (FDM), thereby adding value to waste plastic by converting it into high-value 3D printer filament. This research examines the feasibility of reclamation of waste LDPE milk pouches as filament for 3D printers and studies the changes in filament’s chemical and mechanical properties when produced at different temperatures. The waste milk pouches are cleaned thoroughly, shredded, and extruded using a single screw extruder at three nozzle temperatures, i.e., 150°C, 180°C, 210°C. The extruded specimens are analyzed using an optical microscope and scanning electron microscope (SEM) for surface texture. The effect of change in process temperature on flow behaviors is also studied by integrating a current sensor and an encoder. Fourier transform infrared spectroscopy (FTIR) analysis is performed on the filaments and the used LDPE milk pouches to compare the chemical bondings of the polymer. The mechanical properties of the extruded filaments are examined using dynamic mechanical analysis (DMA). The morphological analysis, chemical characterization, and mechanical characterization of prepared filaments are presented. The results show that the chemical bondings are intact after extrusion at all the temperatures examined in this work. The surface texture and the mechanical properties are better at higher temperatures owing to better fluidity and are more suitable for fused deposition modeling. Thus, it is possible to valorize waste LDPE milk pouches by transforming them into filaments for 3D printing.
Additive Manufacturing of Novel Beam Lattice Metamaterials With Hollow Cross-Sections Towards High Stiffness/Strength-to-Weight Ratio
Authors: Kobir Md Humaun , Liu Xin , Yang Yiran , Jiang Fang 
Published: September 2022

Abstract
Metamaterials have emerged as a group of promising materials with potential applications in a wide range of industries such as aerospace and automobile, owing to their unconventional properties. The state-of-the-art suggests that lattice metamaterials offer lightweight structures while ensuring good mechanical properties, and hollow lattices can be leveraged to achieve ultra-lightweight metamaterials to further broaden the application horizons. In this research, hollow cross-sections are designed for lattice-based metamaterials in order to achieve a high stiffness/strength-to-weight ratio. The Mechanics of Structure Genome method is adopted to perform the beam cross-section analysis, leading to three cross-sections studied including solid, elliptical, and rectangular cross-sections. The designed metamaterials with hollow cross-sections have complex structures and therefore they are fabricated using the Selective Laser Sintering process. The compressive tests suggest that metamaterials with hollow cross-sections have a higher stiffness-to-weight ratio of 25% to 30% in comparison with solid cross-sections. In addition, hollow lattice metamaterials demonstrate better energy absorption capability compared to solid lattices of the same density, which is a critical characteristic to avoid catastrophic mechanical failure. It is observed from the compressive tests that the nodes in the unit cells tend to break first, indicating possible future research to further enhance the strength of hollow lattice metamaterials.
Pre-Crosslinked Hybrid Hydrogels for 3D Bio-Printing Process: Rheological Analysis
Authors: Tuladhar Slesha , Nelson Cartwright , Habib Md Ahasan 
Published: September 2022

Abstract
Bioprinting for regenerative medicine has been gaining a lot of popularity in today’s world. Despite being one of the rigorously studied fields, there are still several challenges yet to be solved. Geometric fidelity and mechanical complexities stand as roadblocks when it comes to the printability of the customized scaffolds. Exploring the rheological properties of the compositions helps us understand the physical and mechanical properties of the biomaterials which are closely tied to the printability of the filament and eventually, geometric fidelity of the scaffolds. To ensure the structural integrity of the scaffolds, viscosity enhancers such as Carboxymethyl Cellulose (CMC) and crosslinkers like CaCl2 and CaSO4 were used. These crosslinkers can be used before (pre-crosslinking) and after (post-crosslinking) the extrusion of considered compositions to investigate and compare the outcome. To do this, mixtures of Carboxymethyl Cellulose (CMC, viscosity enhancer), Alginate, and CaCl2 and CaSO4 (crosslinkers) were prepared at various concentrations maintaining minimum solid content (≤ 8%). Each composition was subjected to a set of rheological tests like Flow curve for shear thinning behavior, three-point thixotropic for recovery rate, amplitude test for gelation point, and frequency tests. This research thoroughly investigates compositions when they are introduced to crosslinkers and viscosity enhancers which can be crucial for 3D printing world.
Robot Trajectory Generation for Multi-Axis Wire Arc Additive Manufacturing
Authors: Bhatt Prahar M. , McNulty Zachary , Gupta Satyandra K. 
Published: September 2022

Abstract
Metal additive manufacturing technology that uses arc welding technology to deposit material is called wire arc additive manufacturing. Robotic manipulators that have a large workspace to size ratio are used to enable wire arc additive manufacturing. Wire arc additive manufacturing is gaining popularity due to the fast build time achieved by the high material deposition rates. It can build large-scale parts at a faster speed compared to other metal additive manufacturing processes. Utilizing a tilting build platform along with a robotic manipulator referred to as a multi-axis setup can enhance the capability of wire arc additive manufacturing. It will allow the setup to build complex supportless geometries that are not possible otherwise. However, maintaining a constant layer height while performing multi-axis wire arc additive manufacturing is challenging due to the forces involved in the process. This paper presents a new sensor-based two-step process along with the tool trajectory generation for maintaining constant layer height while performing multi-axis wire arc additive manufacturing. As the first step, we regulate the tool trajectory velocity to minimize the variation in the layer height. In the second step, we develop a sensor-based intervention scheme to fix the variation in the layer height by introducing additional height compensation layers. Finally, we test our approach by building a few parts, including a tool for the composite layup process.