bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring Invasive Insects Using Artificial Intelligence
Authors: Golan Aviad , Liao Yabin , McNeill Seth
Published: January 2025

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a significant pest for citrus growers in the U.S., due to its ability of transmitting the bacterium responsible for huanglongbing (HLB) disease among citrus trees. The traditional ACP monitoring and controlling methods are time-consuming and labor-intensive. Developing innovative methods to detect ACP and design intelligent traps could greatly enhance management of psyllid infestations and HLB transmission. Monitoring ACP calls between males and females provides an opportunity to detect ACP presence, lure males into traps, or disrupt communication by introducing synthetic calls that interfere with the male signals. This paper presents an artificial-intelligence-based method to detect and classify ACP calls leveraging the multi-resolution feature of the continuous wavelet transform (CWT) technique and the feature extraction and classification capability of deep learning neural networks (DLNN). This method successfully identifies calls with a high accuracy rate exceeding 93%.
Feasibility Study of Self-Lubricated Load Bearings’ Design Within Plug Sliding Door System on Railway Vehicles
Authors: Zhang Liangliang , Zhang Long , Sun Peng , Zhang Tao , Lu Hang , Chen Dongdong , Wu Lvxian , Yin Yanbo
Published: January 2025

The door system on modern railway vehicles is a crucial element in ensuring smooth operation and passenger safety. The current essential load-bearing components within the plug sliding door systems on urban rail vehicles are mainly constructed from metal materials. The imperative maintenance to ensure door safety and operational efficiency is recognized within the industry. During the maintenance of the metal load bearing, the repairers need to remove the old lubricant grease and apply a new one. This procedure increases the cost of the door system’s maintenance and poses the risk of environmental contamination. To address the above consequences, the car builder and the door supplier embark on an initiative to explore the feasibility of replacing these key metal components with non-metal alternatives. This change is aimed at potentially getting rid of the need for lubrication during a single vehicle overhaul period. This article underscores a strategic approach toward enhancing the reliability and cost-effectiveness of urban rail vehicle operations.
AI-Based Machine Condition Monitoring System
Authors: Morris Cameron , Chauhan Vedang , Panchal Sunny
Published: January 2025

This paper describes the approach for an AI-based machine condition monitoring system that utilizes machine learning (ML) and deep learning (DL) techniques to monitor and analyze the condition of machines in various industries. This system employs advanced algorithms and ML models to continuously collect data from sensors, such as vibration sensors, level sensors, and vision sensors, among others. By analyzing this data, the AI system can detect anomalies, predict potential failures, and provide valuable insights into the health and performance of the machines. To demonstrate the feasibility of the concept, the system has been created and implemented for a rotating bowl feeder, a common piece of machinery used for the orientation of parts. Parts ranging from small washers to long-length screws can be dropped into a bowl feeder to be oriented for the next process. As parts become larger and more complex, bowl feeders tend to have more difficulty feeding parts at a high rate (200 to 300 parts/min) and can experience jams. This issue can be compounded if an operator is working on other machinery and doesn’t notice a fault immediately. This paper focuses on using AI for bowl condition monitoring using an ultrasonic level sensor, vibration sensor, part counting sensor, and vision sensor.
Design and Analysis of an Custom Battery Pack Using Solar Energy for an Autonomous Vehicle
Authors: Fernandez Nathan , Lopez Alan , Nandikolla Vidya K.
Published: January 2025

The paper demonstrates the development of a custom lithium-ion battery pack with incorporation of a solar charging system. The design process includes: meeting the power requirements, incorporating a Battery Management System (BMS), Computational Fluid Dynamics (CFD) analysis, and a solar charging system. The Orion Jr 2 BMS and Orion Jr 2 software utility were used to manage the 50V (nominal), 14S8P, 18650 lithium-ion battery pack. CFD analysis was conducted and it was found that simulations from CFD analysis were ideal but deviated from experimental results as the battery pack was not well-balanced, which affected its performance. An electronic DC load was used as an EV emulator. Higher load values exacerbated the imbalance of the battery pack; a load of 8A (448W max) resulted in a maximum delta voltage value of roughly .8V between the cells near the end of the test compared with a value of .16V near the end of the 2A (112W max) test. This project enabled the deeper understanding of the wide range of multidisciplinary engineering topics required to evaluate the design and manufacturing of a safe custom battery pack that can be used for a small intelligent electric vehicle.
Tactile-Based Autonomous Cable Manipulation: Pose Estimation and Connector Verification
Authors: Rosette Marcus , Armstrong Triniti , Nave Keegan , Brown Jostan , DuFrene Kyle , Fitter Naomi , Davidson Joseph R.
Published: January 2025

Automating dexterous tasks such as cable manipulation using robots has proven technically challenging. While vision systems and specialty grippers are available, they often prove unreliable in occlusion-heavy settings typical of cable manipulation tasks like cable tracing or electrical connectivity tests, and they lack the versatility offered by universal grippers. In this paper, we present two contributions related to cable manipulation in manufacturing operations. First, we show an approach for cable pose estimation that uses only in-hand tactile data from fingertip 3D force-sensing tactile sensors. We created a custom gripper and experimental testbed to collect a dataset of tactile cable grasps. We then trained a Long Short-Term Memory (LSTM) network to predict local cable pose and curvature within the grasp. Our second contribution is a classifier that uses tactile data while pulling on a wire to predict whether the wire is correctly seated in its electrical connector. Cable-pull tests were conducted on a testbed with variable cable attachment strengths. This method of tactile perception may better enable autonomous cable routing and contribute to a less subjective standard for cable-pull tests compared to current practices.
AI-Driven Design and Fabrication of Customized Prosthetic Limbs Using Additive Manufacturing and Patient-Specific Optimization
Authors: Al Kharusi Moosa S. M. , Al Maawali Matasam , Al Owiemri Mohammed S. , Al Mushaifri Said , Al Maimani Sulaiman
Published: January 2025

This research paper presents the development of AI-driven design and fabrication of customized prosthetic limbs using additive manufacturing and patient-specific optimization. This innovative approach leverages advanced technologies including artificial intelligence (AI), machine learning, and 3D printing to tailor prosthetic limbs that not only meet but exceed the biomechanical and aesthetic needs of individuals. The study details the integration of high-density polyethylene (HDPE) reinforced with micro and nano-hydroxyapatite (HA) to enhance the mechanical properties and biocompatibility of prosthetics.

The methodology encompasses a comprehensive data collection phase using high-resolution imaging to capture detailed anatomical data. This data is processed using AI algorithms to optimize prosthetic designs, which are then brought to life through state-of-the-art additive manufacturing techniques. The prosthetics undergo rigorous mechanical testing according to ASME standards, with results validated via Finite Element Modeling (FEM) to ensure durability and reliability under physiological loads.

Key findings demonstrate that the inclusion of nano-HA in HDPE significantly improves the tensile strength and modulus, essential for supporting biomechanical functions. User feedback from initial trials underscores the enhanced comfort and functionality of the AI-customized prosthetics, highlighting significant improvements over traditional designs. This research not only advances the technological frontier of prosthetic design but also significantly contributes to personalized healthcare, offering patients prosthetics that are highly functional, aesthetically pleasing, and uniquely tailored to enhance their quality of life.
Toward Support-Free, Zero-Degree Overhang Additive Manufacturing Using a Wandering Center of Motion
Authors: Todd Brody A. , DeVries Levi D. , Kutzer Michael D. M.
Published: January 2025

In recent years, additive manufacturing (AM) has revolutionized traditional manufacturing processes by enabling complex geometries to be printed with enhanced design flexibility and reduced lead times. Current additive manufacturing processes utilize a planar, layer-by-layer deposition of materials ranging from plastics and ceramics to various composites and metals. While these traditional AM methods enable manufacturers to create made-to-order, functional parts, complex geometrical designs with large overhanging features often require sacrificial support structures to maintain material strength and integrity. This research aims to develop a method of AM that adheres to zero-overhang constraints and eliminates the support structure requirements for complex geometries. The proposed method leverages existing research on spherical layering and introduces a novel approach to AM involving a “wandering” remote center of motion (RCM). Using a wandering (i.e. dynamic) RCM, spherical layering techniques can be applied to more complex geometries, specifically geometries that are not within the set of ‘star-convex’ shapes. This paper introduces the wandering RCM method in 2D by developing an algorithm to define unique RCM positions for a given polygon. The goal is to decompose non-star convex polygons into multiple partitions of star-convex shapes, enabling the complete fill of a polygon using a 2D realization of spherical layering. This work leverages an extension to Chvátal’s Art Gallery Problem, using “guard” positions to define RCM positions within the part’s polygonal geometry. Results from 2D analysis demonstrate the feasibility of filling non-convex polygonal regions under a zero-overhang approach.
Gearbox Fault Diagnosis With Deep Learning Under Variable Operating Conditions
Authors: Kalay Onur Can , Karpat Fatih , Karpat Esin , Dirik Ahmet Emir , Ekwaro-Osire Stephen
Published: January 2025

The gearboxes are indispensable universal components to transfer power and handle precision functionalities in modern industry. Their health management is also essential to minimize workforce risks, increase the level of safety, and avoid machine breakdowns. From this standpoint, the present experimental research work developed a convolutional neural network-based method for diagnosing different levels of tooth root cracks (50%–100%) for spur gears. A series of vibration experiments were performed on a single-stage spur gearbox by employing tri-axial accelerometers under variable working conditions. The effects of different levels of tooth cracks on vibration amplitudes were also investigated within experiments. To address the impact of sensor location on the vibration responses of healthy and cracked spur gear pairs comparatively, a total of three sensor locations were determined and tested in the research work. Within the vibration experiments, the impact of two shaft speeds (300 rpm–600 rpm), three loading conditions (zero-load, 10%, and 20%), and three measurement axes (x, y, and z) on the vibrational amplitudes and fault recognition accuracy were evaluated. The findings showed that the proposed convolutional neural network model classified different root crack levels under variable operating conditions between the overall accuracies of 95.015% and 99.970%.
Analysis and Deconvolution of Atomic Force Microscopy Data From Particulate Nanocomposites Through Finite Element Analysis
Authors: Norkus Tyler , Yekani Fard Masoud , Westby Maximillian , Boutin William
Published: January 2025

Introducing nanoparticles into a polymer matrix can improve bulk material properties and fracture toughness while maintaining a low density. The beneficial properties of particle nanocomposites make them a focus for current research, with the intent of identifying and implementing improved manufacturing techniques and materials. One of the techniques that can be used to identify important material properties that impact the performance of nanocomposites is atomic force microscopy (AFM), which can provide detailed data on nanoscale features such as inclusions, changes in the elastic modulus, elasticity, and the presence of an interphase. However, complex nanoscale geometry can produce structural effects that complicate the analysis of AFM data. To aid in the deconvolution of AFM results, this study examines finite element models of AFM indentation onto a particle composite to identify the effects of inclusions, varying levels of confinement, probe size, and an interphase. Data from AFM analysis of carbon nanotubes (CNTs) placed within a thermoset epoxy matrix is used to generate and verify the finite element analysis (FEA). The Derjaguin-Muller-Toporov (DMT) contact mechanics model is used to extract material property data from the AFM and FEA force-displacement results.
Effect of Process Parameters on Mechanical Properties of the 3D Printed Silk-PLA Specimens Fabricated via Fused Deposition Modeling
Authors: Islam Razaul , Shahriar Saquib , Jiang Lai , Peng Xiaobo , Park Jaejong
Published: January 2025

Fused deposition modeling (FMD) is considered one of the most common additive manufacturing methods for creating prototypes and small functional parts. Many researchers have studied Polylactic acid (PLA), Polycarbonate (PC), and Acrylonitrile butadiene styrene (ABS) as a material for fused deposition modeling printing. Among them, Polylactic Acid (PLA) is considered one of the most popular thermoplastic materials due to its low cost and biodegradable properties. In this study, silk PLA material was used. In Fused deposition modeling (FMD), the selection of printing parameters plays a pivotal role in determining the overall quality and integrity of the 3D-printed products. These parameters significantly influence the quality and strength of 3-D printed products. This study investigates the mechanical properties of silk-PLA printed specimens under different printing conditions, such as layer thickness, nozzle temperature, and print speed. All the tensile specimens were tested using ASTM D638 to characterize Young’s modulus and ultimate tensile strength. The thickness of the layers of tensile specimens was set to 0.1 mm, 0.15 mm, and 0.2 mm. The temperatures of the nozzle used during printing varied from 200°C, 210°C, and 220°C, whereas print speeds of 100 mm/s, 120 mm/s, and 140 mm/s were considered. The other printing parameters were kept consistent for all specimens. The result indicates tensile strength generally increases with increasing temperature of the nozzle, up to 220°C; however, a decline was observed in the average Young’s modulus value when the thickness of the layer increased from 0.10 mm to 0.20 mm. According to the results of the ANOVA analysis, the interaction between layer thickness, nozzle temperature, and printing speed significantly affects the tensile strength and Young’s modulus of Silk-PLA. This study reveals that nozzle temperature is the most critical parameter regarding the ultimate tensile strength and Young’s modulus, providing crucial insights for optimizing 3D printing parameters.
Chance Constrained PDE-Constrained Optimal Design Strategies Under High-Dimensional Uncertainty
Authors: Singh Pratyush Kumar , Faghihi Danial
Published: January 2025

This study focuses on developing a computational framework for model-based design of the thermal insulation elements of net-zero buildings based on silica aerogel porous materials, ensuring they provide superinsulation while upholding structural integrity. This approach employs a multiphase continuum model, capturing the thermomechanical properties of the insulation component through a set of partial differential equations (PDE). The framework considers the uncertainty associated with both the physical parameters like elasticity and thermal conductivity for the solid and fluid phases, as well as the design parameter, which is the spatial distribution of the aerogel porosity over the domain of the component. The combination of spatially varying design and uncertainty parameters, along with their finite element discretization, results in a high dimensional PDE-constrained optimal design problem. A mean cost functional is implemented to achieve both target insulation performance and uncertainty reduction during the design process. To avoid stress concentration in the component, chance constraints are included in the optimization formulation, which ensures that the probability of a function that measures the difference between evaluated stress from the multiphase model and a critical threshold value lies within tolerance. A scalable method is introduced for solving PDE-constrained optimization under uncertainty that is both efficient and dimension-independent. For efficiency, this method exploits a second-order Taylor approximation of the design objective and chance constraint function, which solves a generalized eigenvalue problem. Combined with a gradient-based optimization built on Lagrangian formulation, it results in dimension-independent (scalable) computational costs. The numerical experiments on the design of thermal breaks of the buildings demonstrate that the proposed framework leads to a significant reduction in computational cost while preserving thermal insulation performance and avoiding mechanical failure due to stress concentration.
Theoretical and Numerical Analysis of the Log Law and the Richardson-Extrapolation for Numerical Accuracy Estimation
Authors: Epple Philipp , Fritsche Manuel
Published: January 2025

The flow over a backward-facing step is often used for benchmark studies in the field of computational fluid dynamics. In the present contribution, the backward-facing step model is used for analyzing the log law as well as the Richardson extrapolation for numerical accuracy estimation. First, the theory of the often-used log law is shown in detail. With the commercial solver ANSYS CFX different wall refinements are generated and solved and the theory of the log law is compared with the numerical results. The theory to the Richardson extrapolation is shown and validated by different mesh refinements for the backward-facing step model. This method as well as the results are shown and analyzed in detail.
Integration of Underground Heat Exchanger System With Solar Powered Cooling System in Residential Buildings
Authors: Menon Karthik , Ghaith Fadi A.
Published: January 2025

This paper aims to evaluate the integration of an underground heat exchanger with a single-effect absorption chiller along with solar parabolic trough collectors (PTC). The proposed sustainable system contributes to the reduction in CO2 emissions and lowers the energy consumption in residential buildings. The solar integrated cooling system is equipped with a bio-mass heater to provide space cooling during nighttime.

The proposed integrated system was modelled and simulated using TRNSYS. Parametric analysis was conducted to optimize the system’s performance by varying the size of system’s components such as collector area and the volume of the storage tank. The developed system was implemented in two case studies. One is a villa located in Dubai with a cooling load of 175.2 kW/m2 and another one is in located in Abu Dhabi with a cooling load of 376.6 kW/m2. A cost analysis was performed to check the feasibility of the proposed model. The model was validated with the existing literature and showed good match in terms of the gained useful energy.
Transitioning to a Green Hydrogen Economy: Perspective on South Africa
Authors: Oviroh Peter Ozaveshe , Oyinbo Sunday Temitope , Jen Tien Chien , Du Yanping
Published: January 2025

South Africa has significant potential for green hydrogen, and the government is now positioning itself for the transition to an economy based on green hydrogen utilization. However, some challenges require proper attention and addressable solutions to realize such an economy. For green hydrogen to be successful, it is necessary to have widespread and coordinated support throughout the whole value chain. The paper assesses future development, potential, pace, and implications for an environmentally friendly, energy-independent future with highlight in some of these areas.
Vibration Control of a Rigid-Body Inductrack Maglev System
Authors: Wang Ruiyang , Gao Hao , Yang Bingen
Published: January 2025

The Inductrack system, a magnetic levitation strategy based on permanent magnets, has been utilized in many engineering applications since it was envisioned in 1990s. To further implement such Maglev system in high-speed ground transportation, its dynamic behaviors and control methods should be comprehensively studied. Most previous investigations on this topic adopted the steady-state Inductrack model, which is notable but has limited consideration from a dynamics perspective. Recently, a transient model for a 2D, 3DOF Inductrack system has been available, which characterizes the nonlinear, time-varying, and motion-dependent couplings in transient scenarios. Dynamic analysis has shown that both vertical and pitch vibrations of the Maglev vehicle cannot be naturally damped out in most cases, necessitating a feedback control design in the Inductrack system. Presented in this paper is a control design approach for the rigid-body Inductrack system. Firstly, a state feedback linear controller is placed based on a linear reference model and tuned using linear quadratic integral optimal control theory. The linear controller computes the actuation force for each on-board active Halbach array. Secondly, a nonlinear mapping function is identified that outputs the active current density of each array as the control effort. As verified in the numerical examples, the vertical and pitch motions of the Inductrack vehicle can be effectively stabilized under various of traveling speed. Although only a 2D setup is considered, the modeling and control technique developed in this work are fully extendible to address more complicated scenarios.
Compliant Terrestrial Robot Development and Control System Design
Authors: Harms Trevor , Shin Minchul
Published: January 2025

The desired outcome of this paper is to develop sheet-based multi-legged self-folding robots and develop control systems to investigate the physical condition of highly uncertain terrain after its transformation on rough terrains. The robot uses smart material layers for morphing from sheets and locomotion without bulky power sources or accessory systems. The device will be generally applicable in various hard-to-reach regions in space. The research team designed a self-folding robot driven by heating, which consists of two material layers (polymer/metal). Also, multi-legged systems using ceramic smart material have a high driving force and large moving distance. The second task is to design the control system for the determination of space ground condition by analyzing vibrational signals generated by the impact of the pedal system. For future works, the system can recognize how changes in terrain materials and geometry of space impact forcing quantity disturbances.
Exploring Biophysical and Medical Engineering in Physics Education: A Practical Hands-On Approach to Digital Measurement
Authors: Grau Raphael , Düser Tobias
Published: January 2025

Digital measurement technology plays a crucial role in both everyday life and professional contexts. In Germany, the education plan emphasizes the importance of students engaging in digital measurement experiments within Science, Technology, Engineering and Mathematics (STEM) subjects, such as physics. These experiments involve documenting, processing, discussing, and graphically representing measurement results. However, the cost of commercially available measurement packages — comprising sensors, circuits, software, and data storage — can be prohibitive for schools. As a result, some schools only allow teachers to operate them during frontal instruction. Additionally, the acquisition and processing of sensory data often occur within sealed black boxes. To address these challenges, the open-source project Data Acquisition for Physics Education with Raspberry Pi (PhyPiDAQ) introduces a cost-effective, universally applicable data acquisition system. It empowers students to actively construct measurement circuits and explore the fascinating world of digital measurement technology. Current studies show that students identifying as female are significantly underrepresented in STEM disciplines, while interdisciplinary vocational training and degree programs related to social sciences and medicine are particularly popular among people identifying as female. Therefore, this paper presents medical technology and biophysical use cases for PhyPiDAQ, such as an ECG built by students themselves, and explains the didactic framework.
Teaching Modeling and Vibrations Fundamentals With a Compliant Quasi-Zero Stiffness Mechanism and Virtual Lab Simulations
Authors: Simpson Sawyer , Gorman Joey , Dinh Peter , Schwenck Lucas , Tekes Coskun , Utschig Tristan , Tekes Ayse
Published: January 2025

Learning mathematical modeling of dynamical systems and mechanical vibrations has significant challenges due to the abstract and mathematically complex nature of these subjects. The complexity is compounded when students lack a strong foundation in mathematics and dynamics, presenting a challenge for instructors. It is well-known that hands-on learning can significantly enhance student understanding by linking theory with its practical application. This study introduces the design of low-cost laboratory equipment complemented with its virtual lab simulations. The developed apparatus consists of a compliant parallel arm mechanism with four fixed-free compliant links and a primary mass-compliant link mechanism, the latter augmented with horizontally attached, initially preloaded beams serving as quazi zero stiffness (QZS) springs. The compliant parallel arm mechanism is actuated by a linear actuator, and the displacement of two masses are recorded via laser displacement sensors. The horizontal beams, preloaded using a screw-nut set to maintain same deformation, are central to the mechanism’s design. The lab equipment is 3D printed from polylactic acid (PLA). The virtual lab of the hands-on equipment is also created in MATLAB Simscape as a GUI program to allow students to change the geometric dimensions and material properties of the flexible beams as well as the input force including its amplitude and frequency.
Linking Early Robust Design With Quantitative Methods for Enhanced Industrial Applications
Authors: Li Jiahang , Long Yiming , Döllken Markus , Zhang Yizhe , Wu Guangqiang , Matthiesen Sven
Published: January 2025

Robust Design (RD) in the early design stages has a critical impact on product development costs. However, the application of the early RD methods in the industry is limited, as they cannot be easily integrated into standard development processes. In order to effectively use qualitative early RD methods in the development process of industrial products, a link to the quantitative methods in the development process is needed, which is currently lacking. To address this gap, this paper investigates the application of an early RD method with the Embodiment Function Relation and Tolerance (EFRT) model in an industrial context, focusing on the development of the centrifugal pendulum vibration absorber that is widely used in vehicle drivetrain system. The insights gained from the qualitative modeling are then linked to a quantitative simulation model in the software Matlab/Simulink. The results of the EFRT model and the simulation are compatible and can be effectively linked to improve the robustness evaluation of industrial products. With this link, early RD methods could be better integrated into the development process of industrial products, and therefore provide more benefits to engineering practice.
A Comparative Analysis on the Effect of Hydrogen Addition on Combustion Behavior of Methane, Ethanol, and Ammonia
Authors: Roy Shrabanti
Published: January 2025

To reduce the harmful emissions from energy generation efficient use of the available sources of fuel is vital. In this current work hydrogen dilution with methane, ethanol, and ammonia is considered to comparatively study the effect of these fuel blend on combustion characteristics. Each of these fuels are potential sources of energy with certain limitations either in efficiency or emission quality. The mixture composition of 20-80, 50-50, and 90-10 percent hydrogen with methane, ethanol, and ammonia is considered for the comparison. Laminar burning speed (LBS), and ignition delay time (IDT) are calculated numerically for the comparative analysis of these three fuel blends. To predict the influence of hydrogen on emission quality, change of species concentration with temperature is calculated. The IDT is calculated at stoichiometric condition, 1100–1900 K temperature and 10 atm pressure. The initial temperature of 400 K and 0.6 to 1.4 equivalence ratio is used for LBS calculations. With the help of sensitivity analysis, the effect of mixture on important reaction is studied. The concentration changes of CO, CO2, NO, and NO2 is compared between various hydrogen blends of different fuel.
Comparative Analysis of Vortex Field Measurement Around MHK Turbine Blades Using PIV and CFD Techniques
Authors: Hafdaoui Amin , Tanaka Shin , Doan Minh N. , Obi Shinnosuke
Published: January 2025

Cross-flow turbines have been recently re-discovered in the fields of wind and tidal energy thanks to the high power density they can provide when arranged in arrays. In this paper, we investigate the mechanism of torque generation and maintenance of a pair of miniature Marine Hydrokinetic Turbines via Particle Image Velocimetry, providing new insights on the influence of vortex shedding onto the lift generation process. The velocity field around the blades was measured for two different tip speed ratios and across various configurations of the devices, to then evaluate the forces involved by performing a momentum balance over moving control volumes. Our findings suggest that a lift force was first generated, in line with the airfoil theory, by the flow acceleration on the inner surface of the blade, and was subsequently maintained after the onset of dynamic stall by the low pressure associated with a leading-edge vortex. Furthermore, increases in tip speed ratio and blockage effect were observed to positively impact vortex strength and torque production. The results were compared with two-dimensional CFD studies for the purpose of validating the control volume method for torque estimation, as well as discussing and quantifying the 3D effect.
Active Piezoelectric Metastructures: Relationship of Bandgap Formation With Unit Cell Number and Modal Behaviour
Authors: Kaczmarek Marcin B. , Gupta Vivek , HosseinNia S. Hassan
Published: January 2025

Elastic piezoelectric metastructures with actively implemented resonators offer an opportunity for novel vibration attenuation solutions, thanks to the possibility of creating bandgaps at low frequencies, their tuneability and compactness. We focus on metastructures with sensors and actuators, where the resonators are implemented using feedback control techniques, an alternative to commonly used shunt circuits. For bandgap creation in finite structures, unit-cell-based dispersion analysis is unsuitable since it lacks information on modal behaviour. As an alternative, a modal analysis approach can be used to calculate the frequency range of a locally resonant bandgap in closed form using the assumption of an infinite number of transducers of infinitesimal length distributed along the structure. The predictions obtained using this approach are accurate if a sufficiently high number of transducers is used, and the number required increases with the increasing target frequency. Despite the recent developments in the field, it remains to be seen what the sufficient number is in a specific situation. In this paper, we show that for low-frequency bandgaps in cantilevers, the minimal number of transducers is equal to the number of the dominant vibration mode at the targeted range of frequencies. Increasing the number of transducers above this value increases the vibration attenuation in the bandgap region but does not result in its widening. The result is demonstrated using numerical analysis.
Material, Torque, and Structural Study of a Foldable Robotic Arm for Aerial Drones
Authors: Bingham Kyler , Zakrevski Christopher , Deemyad Taher
Published: January 2025

The paper discusses the integration of foldable robotic arms into unmanned aerial vehicles (UAVs), particularly focusing on their application in precision agriculture for fruit picking. The design process, from conceptualization to 3D modeling, ensures the arm’s functionality while minimizing interference with the drone’s flight dynamics. Material selection, emphasizing the balance between strength and weight, favors Onyx, a nylon blend reinforced with carbon fiber, and the honeycomb infill pattern for its exceptional mechanical properties. Torque analysis confirms the arm’s manageable impact on UAV stability. The research underscores the potential of foldable robotic arms to enhance UAV capabilities in various tasks, offering insights into their broader applicability beyond agriculture. It contributes to UAV design and robotics by addressing challenges in integrating functional accessories, emphasizing the importance of material selection and structural design in optimizing UAV performance.
Advanced Material Selection and Design Strategies for Optimized Robotic Systems
Authors: Bingham Kyler C. , Sourani Yancheshmeh Sara , Vaidya Greesh , Ebrahimpour Arya , Deemyad Taher
Published: January 2025

Efficient lightweight structures with high strength are crucial across engineering disciplines, often drawing inspiration from natural patterns. However, traditional manufacturing methods struggle to replicate their intricate geometries. The rise of additive manufacturing offers a promising solution by enabling the fabrication of complex structures previously deemed impractical. In this study, we investigate nine natural-inspired patterns using SolidWorks for design and analysis. Mechanical properties of Nylon carbon fiber 12 as one of the materials well-known for having a high weight-to-strength ratio are derived from experimental tensile tests. The results have been compared with traditional materials like aluminum and steel, along with two common 3D printing materials. Through this comparative analysis, we assess the potential of additive manufacturing for creating lightweight yet robust structures. Practical applications, such as the frame of an aerial drone and the top plate for an autonomous ground vehicle chassis, are considered. The findings shed light on additive manufacturing’s role in advancing structural engineering across various applications, offering insights into its feasibility and benefits over conventional manufacturing methods.
Nonlinear Vibration and Bifurcations of a Bending-Twisting Rotor System
Authors: Chen Yuanhao , Chen Bin , Wang Xinya , Xu Yeyin , Wang Tieyan
Published: January 2025

In this paper, a nonlinear dynamic system of a bending-twisting rotor is studied. Analytical prediction of nonlinear vibrations in such a nonlinear dynamic system are presented from the implicit mapping method. Bifurcations on vibration evolution are obtained and the stability of the corresponding vibrations are discussed by eigenvalue analysis. Period-doubling bifurcations occur when the rotating frequency varies where subharmonic vibrations emerge. The discrete Poincare displacements and velocities of periodic vibrations exhibit the motion complexity and give good scenarios of the bifurcations. Illustrations are given for comparison of the analytical and numerical results of nonlinear vibrations. The obtained results can be used to design and control the bending-twisting rotor with environmental noise.
Performance Tests for 3-D Pulsating Heat Pipe Heat Exchanger Under the Horizontal Orientation
Authors: Cheng Po-Shen , Wong Shwin-Chung , Wu Shih-Kuo
Published: January 2025

Waste heat recovery greatly reduces energy consumption by recapturing the wasted energy generated during industrial processes. An efficient air-to-air PHPHX system for waste heat recovery was established, in which up to three sets of PHPHX unit could be accommodated. Each fin-integrated PHPHX unit was modified from commercial products, involving total thirty-six 6 mm tubes arranged into three connected layers that a single charge suffices. Water with a filling ratio of 50% acted as the working fluid. Under the horizontal orientation, the three connected tube layers provide a cross-layered flowing behavior, beneficial to pulsation incitation. Since gravity still existed in the depth direction, the liquid slug trains continued to flow back to the evaporator section in the lower tube layer after being pushed upward by nucleate boiling. The pulsation was stably sustained at THI ≥ 55 °C by the endless up and down circulation. The maximum effectiveness for horizontal waste heat recovery was 0.46, merely 5–7% lower than the vertical operation. However, in the PHPHX with three independent tube layers, only the unbalanced vapor pressure with randomness and uncertainty dominated the movement of liquid slug trains. The evaporator section commonly stayed in the state of dry-out until THI = 80 °C that a tottering pulsation motion appeared with a maximum effectiveness less than 0.4. The present study validates the merit and practicality of the multiply connected tube layer design and extends the application from the vertical to the horizontal orientation.
Study of the Performance of Compressor Stations With Gas Turbines When Operating With Mixtures of Hydrogen and Natural Gas
Authors: Fajardo Juan , Barreto Deibys , Yabrudy Daniel , Rangel Richard , Garcia Samira , Sanjuan Marco
Published: January 2025

Researchers are addressing challenges transitioning from natural gas to hydrogen, particularly in transportation and compression. This study evaluates the performance of a gas turbine compression system that compresses gaseous fuel, focusing on a SolarTurbines TAURUS 60 gas turbine with an output power of 5740 kW and nominal efficiency of 32 %. The 12-stage Solar C33 compressor achieves a maximum total head of 257 kJ/kg and an isentropic efficiency above 80%. Energetic, exergetic, and exergoeconomic analyses were conducted for various hydrogen/natural gas mixtures. The results indicate a reduction in CO2 emissions of 187.5 kg per ton of fuel processed with every 10% increase in hydrogen content. Furthermore, setting the oxygen percentage in turbine exhaust gases at 14% and increasing the hydrogen content by 50% reduced the air and fuel requirements by approximately 15%. The Turbine-Air Compressor Work Ratio decreased with higher hydrogen fractions, enhancing the compression train energy efficiency from 6.28% to 27.21%. Exergy analysis revealed decreased total exergy destruction and increased exergetic efficiencies with increasing hydrogen percentage, except for the combustion chamber and gas turbine. Exergoeconomic analysis indicated an increase in the specific cost of gas with higher hydrogen fractions, reaching $20.56/Gj for 100% hydrogen.
Influence of Exhaust Gas Recirculation in Biomass Combustion
Authors: Castro Carlos , Teixeira José , Ferreira Manuel , Fraga Lelis
Published: January 2025

The implementation of an Exhaust Gas Recirculation System (EGRS) into a prototype 20kW domestic pellet boiler was studied. The boiler’s power, primary and secondary slit ratio and grate area were fixed, and the excess was adjusted to the three throttle positions studied. Several parameters were measured, including the fuel bed temperature at different heights and some exhaust gas species as: carbon monoxide (CO), carbon dioxide (CO2) and oxygen (N2). The tests were conducted always with the goal to reduce the CO as this implies and increase in the combustion efficiency. The results show that with the opening of the EGRS throttle from 0 to 100% the fuel bed temperature decreased in 13% at 5mm, 2% at 15 mm, 22% at 25 mm and 14% at 60 mm of heigh. Regarding the gas species, form the EGRS throttle fully closed to fully open, the CO2 increased 4%, while the O2 and CO decreased 12% and 32% respectively.
Efficient Autonomous Navigation for GPS-Free Mobile Robots: A VFH-Based Approach Integrated With ROS-Based SLAM
Authors: Tereda Amanuel , Yi Sun , Li Xingguang
Published: January 2025

Simultaneous Localization and Mapping (SLAM) is an autonomous localization technique used for mobile robots without GPS. Since autonomous localization relies on pre-existing maps, to use SLAM with the Robotic Operating System (ROS), a map of the surroundings must first be created, and a controller can then use the initial map. The first mapping procedure is mostly carried out manually, with human intervention. When operating manually, the person operating the robot is responsible for avoiding obstacles and moving the robot to different sections of the space to create a full map of the entire environment. The mapping process, if done manually, is time demanding, and often not feasible. To solve this constraint, which is to construct a map of the environment autonomously without human involvement while avoiding obstacles, the Vector Field Histogram (VFH) technique is implemented in this study by integrating it with SLAM. VFH is a real-time motion planning approach in robotics that uses a statistical representation of the robot’s surroundings known as the histogram grid, to place a strong emphasis on handling modeling errors and sensor uncertainty. Furthermore, using range sensor values, the VFH algorithm determines a robot’s obstacle-free driving directions. Aside from its real-time obstacle avoidance function, the VFH method is enhanced in this study to collaborate with SLAM to create maps and reduce localization complexity. While generating maps, the VFH approach uses a two-step data-reduction procedure to calculate the appropriate vehicle control directives. The robot’s temporary location is used to generate a one-dimensional polar histogram, which is the first stage of the histogram grid reduction process. The polar obstacle density in a given direction is represented by a value in each sector of the polar histogram. In the second stage, the robot’s steering is oriented in the direction of the most appropriate sector, which the algorithm determines from all the polar histogram sectors with a low polar obstacle density. Following that, further algorithms, such as Rapidly Exploring Random Tree (RRT) and A*, can be used to plan autonomous pathways using the map provided by VFH. In order to put the concept into practice, MATLAB and ROS are used together in collaboration to autonomously and simultaneously map the environment and localize the robot. The combination of MATLAB and ROS provides many advantages because of their extensive feature set and ability to integrate with each other. Finally, a simulation and a real-time robot are utilized to analyze and validate the study’s findings.
Determination of the Effect of Lifting Load Edge Radius on a Wire Mesh Sling
Authors: VanName Joshua M. , Rahman A. H. M. E.
Published: January 2025

Lifting equipment can have a diminished capacity when the lifting force reacts against an edge of a load that is not sized appropriately. The purpose of this work was to determine the influence of varying edge radius sizes on the lifting capacity of wire mesh slings; this research objective directly targets scenarios where wire mesh slings are used in a basket hitch around a load with edges and direct contact is made between the edges and the sling. Unlike for other forms of lifting slings, little information exists for the specific use of wire mesh slings on loads with edges. The existing guidelines and recommendations for this topic will be summarized for the other types of slings which will reveal the motivation to pursue this research for wire mesh lifting equipment. For this work, wire mesh slings were experimentally tested to destruction and explicit dynamics simulations were performed in ANSYS to supplement the experimental tests. The experimental results show that up to a 33.6% reduction in load bearing capacity may occur when using a wire mesh sling in a basket configuration around a load with edges; however, the sharp edges deformed during the experimental testing. ANSYS simulations show that up to a 37.8% reduction may occur when the edge is defined as a rigid body with no deformation. A 5.2% error was achieved between the maximum straight pull, or vertical hitch, sample of the control group and the simulated straight pull test. Lastly, a 4.2% absolute error was found between the maximum percent reduction in load bearing capacity between the experimental and simulation results.
Examination of the Effect of Equipment Nozzle Load on Metal Compensators Using Solid Mechanics and FEM
Authors: Magesh Agraja , Ganesan Umamagesh , Sekar Arasu , Sundararajan Raji
Published: January 2025

This is a comprehensive study on the effect of equipment nozzle load on the metal compensator (also known as the expansion joint or bellows) utilizing the principles of solid mechanics and the Finite Element Method (FEM). Metal bellows-type joints/compensators are flexible components of the equipment or piping system that can accommodate thermal expansion, vibration, and movement. The ability to accommodate movement within the piping/equipment system is vital for ensuring its efficiency and safety. These expansion joints facilitate the necessary flexibility and mitigate the risk of potential damage or failure in equipment/piping design. The metal compensators are strategically positioned to address displacement challenges within the system, facilitating movement while maintaining stability. This study focuses on the force and moments generated by equipment nozzle load, which is crucial for the compensator’s functionality. When branch lines or nozzles are installed or present in proximity to thin-walled metal bellows-type expansion joints, they produce multidirectional loads and moments. The intricate design necessitates Finite Element Analysis (FEA) to assess the deflection and its stresses at different locations of the expansion joint. Torsion, or twisting, applies a rotational force to the joint, which must be minimized or eliminated. When these forces generate torsional moments on the expansion joint, it is necessary to employ accessories that effectively isolate the metal bellows from such effects, as these joints are not designed to accommodate substantial torsional loads. By employing such hardware, the expansion joint can perform its intended purpose of absorbing axial, lateral, and angular movements within the piping system, contributing to its overall reliability and performance. Solid mechanics concepts were utilized to convert these forces and moments into axial, lateral, and angular movements. FEM analysis employing ANSYS Tools further evaluated these movements, with the obtained data integrated into the fatigue evaluation process. The study also identifies torsional loads from sustained and occasional equipment loads, implementing effective restraint hardware to isolate the compensator and maintain shear stress within allowable limits. These methodologies provide valuable insights into the behavior of metal expansion joint assemblies under such conditions/equipment, allowing for the determination of maximum deflection caused by the resultant force and moment of the nozzle load.