bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of Fatigue Damage in Aluminum Alloy Structures Using Nonlinear Ultrasonic Modulation
Authors: Yan Ling , Luo Lijia , Zhong Fengping , Zhao Zuming , Fan Jingjing , Huang Liuyi , Bao Shiyi , Mao Jianfeng 
Published: January 2022

Abstract
In this paper, a nonlinear ultrasonic modulation method is developed to detect early fatigue damage in aluminum alloy structures. Seven aluminum alloy specimens with different fatigue damage degrees are prepared by fatigue test. An experimental system is designed for performing nonlinear ultrasound modulation detection of fatigue damage in aluminum alloy specimens. A single piezoceramic transducer is used to emit two superposed sinusoidal waves with different ultrasonic frequencies. The higher frequency is chosen as a non-integer multiple of the lower frequency so as to be distinguished from super-harmonic responses. The dependencies of the nonlinear modulation response on the frequency and amplitude of excitation signals are explored to select appropriate signal excitation parameters. A nonlinear modulation index (NMI) is defined as the amplitude ratio of modulation responses and linear responses, which is used to evaluate fatigue damage of specimens. Experimental results indicate that the NMI increases monotonically with the degree of fatigue damage, and it can be used to quantify the accumulation of fatigue damage in specimens. The proposed nonlinear ultrasound modulation method facilitates the detection of fatigue damage and further assessment of the severity of the damage in aluminum alloy structures.
Virus Detection and Medical Diagnostics Student Projects for the Internet of Medical Things
Authors: Mauk Michael G. , Chiou Yunshun (Richard) , Tseng Tzu-Liang (Bill) 
Published: January 2022

Abstract
The importance of medical diagnostics, and specifically, tests for infectious agents such as viruses, is well recognized, and in fact, are a crucial component of efforts to control pandemics and mitigate their effects on public health. A long-established trend is the development of low-cost, easy-to-use point-of-care (POC) diagnostics to provide pervasive, timely testing independent of laboratories and other medical infrastructure. The technology of POC tests is widely accessible to engineering students, and there are many opportunities and avenues for innovation, including Smartphone-based platforms and integration with the Internet of Medical Things (IoMT). We discuss the design, demonstration, and testing of POC virus testing, including tests applicable to COVID-19, as Senior Design Projects for undergraduate mechanical, electrical, and manufacturing engineering majors.
Topology Optimization of Cracked Structures With Manufacturing Constraints
Authors: Habibian Anahita , Sohouli Abdolrasoul , Suleman Afzal 
Published: January 2022

Abstract
Topology optimization (TO) is a tool used in the design process to improve the structure’s performance, e.g. increasing the stiffness. However, the final topologies typically include complex shapes making them impractical or unrealizable from a fabrication point-of-view. This issue stems from the limitations that the currently available manufacturing methods have, such as milling. Hence, considering these limits as the manufacturing constraints into the optimization problem would shorten the post-processing time. Moreover, the existence of initial damage such as cracks is another common issue of engineering structures, resulting in unreliable topologies if neglected. These two challenges are the main motivations of this study. A projection method is utilized to restrict the range of solutions to a manufacturable design domain by projecting the design variable into a pseudo-density field. The main advantage of this approach is that the manufacturing restrictions are achieved naturally, without adding constraints to the TO problem, which leads to a straightforward calculation of sensitivities. This technique allows the designer to define, for instance, a minimum member size as well as a minimum hole size as geometrical constraints. In order to penalize the intermediate phases, the popular Solid Isotropic Material with Penalty method (SIMP) is employed. The Peri-dynamics theory is used to study the structure’s behaviour because of its ability to introduce discontinuities without requiring complicated mathematical expressions as opposed to its counterpart mesh-based approaches. The robustness of the proposed method is demonstrated through some compliance minimization problems.
In-Situ Scanning Electron Microscope Chemical Vapor Deposition as a Platform for Nanomanufacturing Insights
Authors: Koerner Gordon , Surya Ramakrishna , Palaniappan Kannappan , Calyam Prasad , Bunyak Filiz , Maschmann Matthew R. 
Published: January 2022

Abstract
While the physical properties of carbon nanotubes (CNTs) are often superior to conventional engineering materials, their widespread adoption into many applications is limited by scaling the properties of individual CNTs to macroscale CNT assemblies known as CNT forests. The self-assembly mechanics of CNT forests that determine their morphology and ensemble properties remain poorly understood. Few experimental techniques exist to characterize and observe the growth and self-assembly processes in situ. Here we introduce the use of in-situ scanning electron microscope (SEM) synthesis based on chemical vapor deposition (CVD) processing. In this preliminary report, we share best practices for in-situ SEM CVD processing and initial CNT forest synthesis results. Image analysis techniques are developed to identify and track the movement of catalyst nanoparticles during synthesis conditions. Finally, a perspective is provided in which in-situ SEM observations represent one component of a larger system in which numerical simulation, machine learning, and digital control of experiments reduces the role of humans and human error in the exploration of CNT forest process-structure-property relationships.
Design of a Horizontal Axis Wind Turbine for a Venusian Environment
Authors: Garza Zacharias , Pan Kevin , Izaguirre Anthony , Loza Saul , Serrano Jonathan , Lopez Oscar , Kuo Jim , Sauder Jonathan 
Published: January 2022

Abstract
The atmosphere of Venus is 96% carbon dioxide and contains clouds of sulfur dioxide and sulfuric acid, with surface temperatures in excess of 470°C and pressures 92 times that of Earth. These extreme environmental conditions make planetary exploration difficult, as modern electronics cannot survive for prolonged periods of time. Photovoltaics, a conventional power generation method for Mars rovers, are inefficient on the planet’s surface due to the dense cloud cover and harsh environment. The NASA – JPL Hybrid Automaton Rover Venus proposes using a mechanical wind energy harvester to further explore the Venusian surface. At the proposed landing site, the surface wind speeds range from 0.3 to 1.3 m/s with an average wind speed of 0.6 m/s. These wind speeds, combined with the high density of Venusian air, results in promising potential for power generation. The power goal for the proposed wind harvester is 9W at the average wind speed of 0.6 m/s. A horizontal axis wind turbine (HAWT) is used to avoid dynamic stall experienced by vertical axis wind turbines at low wind speeds.
In the HAWT, existing airfoil profiles were evaluated and chosen using an iterative design process. The blade designs were analyzed using blade element momentum theory (BEM) to predict and improve turbine performance. Testing was performed in water, as the greater fluid density allowed for testing at a lower speed than in air to better simulate Venus surface conditions.
The preliminary water testing was carried out to characterize turbine performance. In this process, a 3D printed PLA 1:4 scale turbine was placed in an open-channel pool with flow supplied through a pump. The turbine was a fixed 2.3 m distance away from the inlet of the flow. The flow speed, turbine rotational speed, and torque produced were recorded. The results yielded turbine efficiencies between 7.7% and 46.1%. These results exceeded design expectations at the designed TSR, where an efficiency of 40% was to be expected.
Based on the preliminary results, modifications are being made to the water testbed to improve the testing process as well as more accurately simulate conditions on the surface of Venus. The collected data and the aforementioned design tools are used to improve the current turbine design.
Physicochemical Characterization of the Rejected Waste From the Mechanical and Biological Treatment of Municipal Solid Waste
Authors: Oliveira Victor , Castro Fernando , Teixeira Jose Carlos , Araujo Jorge , Ribeiro Andre , Carvalho Joana , Vilarinho Maria Cândida 
Published: January 2022

Abstract
Mechanical and Biological Treatment units (MBT), are a key element in the management of municipal solid waste as they are the preferred route for minimization of the amount of waste delivered to landfills. However, taking into account the waste received by the MBT’s, it is observed that a significant part is sent to controlled landfills without any kind of valorization. Within this framework, a characterization of the rejected waste produced in one of these facilities was carried out in order to assess their potential for energy recovery. The rejected waste is composed by different fractions, namely paper, textiles, plastic films, hard plastics, glass, metal, organic matter and undifferentiated waste. In the present work the rejected waste from a MTB unit is sorted into different classes and each one is fully characterized and assessed as an energy source. For the physicochemical characterization of different residues the following tests were performed: weight loss at 105 °C, elemental analysis, the determination of the heating value, thermogravimetric analysis and FTIR spectroscopy. Considering the potential for energetic recovery of the different fractions, only paper, textiles, hard plastics and plastic films were characterized because of the high moisture content of organic material. According to the results, there is a great variability of the physical-chemical properties within the various samples, both in composition and moisture. Most notably the polymer based residues (hard plastics and plastic films) show a heating value that compares favorably with both traditional biomasses and fossil fuels. Therefore, providing their acceptance in terms of toxicity, they can provide a valuable source of energy and contribute to the reduction of waste delivered to landfills.
A Study on Degradation of Lithium-Ion Batteries for In Aircraft Applications
Authors: Alhadri Muapper , Zakri Waleed , Esmaeeli Roja , Farhad Siamak 
Published: January 2022

Abstract
Some lithium-ion batteries (LIBs) applications are mobile and stationary energy storage systems such as electric vehicles (full electric, hybrid and plug-in hybrid), different types of aircraft, and renewable energy technologies. LIBs can play a tremendous role in replacing the considerable dependence of nations on fossil fuels due to the high storage energy density of renewable energy alternatives. They also have a high cost associated with the material costs, as well as the other manufacturing costs. The environmental impact of manufacturing and disposing lithium-ion batteries has triggered actions to reduce the resulting impact by recycling batteries.
Degradation of LIBs is always a concern for any application. To predict the life of cells correctly, it is more efficient to cover all mechanisms leading to capacity-fade or resistance growth. This study discusses the degradation rate of a LIB at two stages of life for both first- and second-uses. Empirical models can be used to measure capacity-fade, resulting from the battery degradation. The duty-cycle of the commercial LIB for a typical passenger aircraft, such as the Bombardier CRJ200, was obtained. For this purpose, the velocity and altitude of the aircraft were monitored during a typical flight, and the instantaneous mechanical power of the aircraft was obtained by modeling. Then, the duty-cycle of a LIB cell in the battery pack was yielded. The life prediction of the LIB in electrical energy storage for aircraft was studied. Although many studies have been done to evaluate performance and durability of LIB cells and packs for vehicle applications, there are very few studies of the application of LIBs in electric and hybrid aircraft. The degradation rate of the battery for a typical lightweight passenger aircraft with a flight range of less than 1000 km was then presented by using an empirical modeling method. The results showed that the A123 battery (20 Ah) degraded after 6 months at 45°C and 80% State of charge (SOC) and after 1.8 years at 45°C and 80% depth of discharge (DOD) by assuming that the battery should be retired when the rate of degradation reaches 15% of its nominal capacity. It was found that a retired first-use LIB cell is durable enough to be utilized in many second-use applications which can have lots of environmental benefits. Several items related to second use of LIBs will be discussed in this paper.
Influence of Instantaneous and Delayed Overlaps on Surface Topography and Wettability of a Femtosecond Laser Textured Surface
Authors: Siddiquie Reshma Y. , Bathe Ravi , Agrawal Amit , Joshi Suhas S. 
Published: January 2022

Abstract
Surface topography modifications using an ultra-short laser is a well-known technique to tune surface characteristics like hydrophobicity, anti-biofouling, anti-icing, enhanced lubrication, and several others. Understanding correlations between surface topography and laser parameters can help generate textures for many useful applications. In this work, the influence of instantaneous and delayed pulse overlap along with the effect of fluence on the femtosecond laser textured surface was investigated. The result shows that, an increase in 10 J/cm2 accumulated fluence can cause a 43% rise in oxygen level on surfaces, with the increase pulse overlap, an increase in the surface roughness (Sa) (0.08 to 0.2 μm) as well as height of the pillars (5–10 μm) was observed. A decrease in surface roughness was observed with a change in line overlap. Other results shows that the spacing between the lines can be increased with a decrease in the line overlap. At the lower pulse overlap, individual pulses were observed with diameter of 5 μm. In addition, the profiles of the microstructures also varied with laser parameters. Sharper pillars were observed at low value of fluence (4.78 J/cm2), whereas with an increase of 10% in pulse overlap along the scan direction, the height of the pillar increased by 5 μm. Larger burr formation and higher surface roughness Sa were observed on stainless steel substrates as compared to that of on Ti6Al4V substrates.
Preliminary Design and Experimental Studies of a Compliant Knee Joint for Pediatric Above Knee Amputees
Authors: Pitre Sahil , Curtin Bryan , Pena Paul , Rouse Ciaphus , Joseph Emma , Hooper Joshua , Tekes Ayse 
Published: January 2022

Abstract
This study presents a passive, self-actuated, 3D printed compliant knee joint for children in developing regions to decrease the overall expense of above knee prosthesis as well as increase the ease to print multiple prosthesis during their growing cycle. A single piece designed five-bar mechanism is proposed to provide adequate human-like gait instead of the traditional pegleg gait provided in previous rigid models. This gait is achieved through the use of both compliant links as well a novel 3D printed approach which is more accustomed to children because of the mechanism’s lightweight. In addition to the compliant knee joint, a compliant ankle possessing a flexure hinge placed at the toe is also designed to provide required bending during the gait cycle. The approach of using a fully passive knee joint enables to limit the weight of the prosthesis to create less of a burden to children and by isolating the need to utilize motors. A test bench consisted of a rack-pinion, two parallel rods, supports, and two servo motors are fabricated to experiment the performance of the knee joint. While the test bench is 3D printed using polylactic acid (PLA), the compliant knee joint is 3D printed in thermoplastic polyurethane (TPU) to emulate the gestures of a real human leg. Simulations are performed in Matlab Simscape to validate that the proposed knee joint mimics the human knee and desired angles.
Stress Analysis of Additive Manufactured Lightweight Spur Gears
Authors: Yılmaz Tufan Gürkan , Kalay Onur Can , Karpat Fatih , Ekwaro-Osire Stephen 
Published: January 2022

Abstract
Additive manufacturing processes (AMP) have grown and spread in the last twenty years. Additive manufacturing methods, which were first used for plastic materials, are now increasingly finding a place in metals. With these methods, more lightweight component designs which cannot be generated with traditional methods can be manufactured. With the spreading of electric drive vehicles, weight reduction is becoming more important since weight is primarily responsible for energy consumption. There is a one-stage gear system in electric vehicles in general. For this reason, the subject of reducing the mass of gears is gaining importance. The weight reduction can be achieved with holes and slots on the gear body for involute spur gears or reducing gear web thickness. Several optimization methods can be used for this aim. Another way is to use light materials for the gear body, while steel material is used in the tooth-rim region. Carbon fiber composites are preferred for this purpose. However, using adhesives to join steel and carbon fiber reinforced plastics may cause problems in different environmental conditions. On the other side, parts are generated with single material with AMP methods. In this study, involute spur gears with different designs convenient for generation by AMP are created in a 3D CAD program. The involute tooth region is defined as design space. The effects of different designs on root stress and tooth stiffness are investigated by finite element analyses. For this purpose, the mathematical modeling of involute spur gear is set to get points of a tooth based on Litvin’s approach in MATLAB. A point cloud code is obtained and imported to the 3D CAD program. After that, three teeth 3D finite element spur gear models are generated. Static analyses are conducted in ANSYS. Meshing force is implemented on the highest point single tooth contact line. Root stress value is the most important reason for tooth root fatigue, one of the most common failure modes of involute spur gears. Tooth deflection and stiffness are significant parameters for the dynamic behavior of involute spur gears. The tooth stiffness affects mesh stiffness and transmission error which are the primary source of gear whine. For these reasons, tooth root stress and tooth deflection values should be determined for different gear designs.
In this study, stress analyses of additive manufactured gears are conducted with the finite element method. The effect of shell thickness, infill radius, and infill stiffener on tooth root stress and deformation is recorded. According to the results, shell thickness is the most effective parameter on the root stress and deformation. It is followed by infill orientation angle and infill radius, respectively.
Tribological Evaluation of a High-Performance Composite Coating
Authors: Renner Peter , Gharib Mohamed , Liang Hong 
Published: January 2022

Abstract
This research presents a new coating on a metal substrate. A carbon steel substrate was used to apply Ni-SiC coatings of various ratios. Wear tests were performed on the coatings and substrate using a linearly reciprocating tribometer with a E52100 carbon steel counterpart. Scratch tests were performed with the same instrument using a tungsten carbide scratch tip. The addition of the coating was found to greatly improve the mechanical properties of the substrate. During experiments studying wear, an E52100 carbon steel ball counterpart was used and its damage was analyzed. This ball showed signs of wear while the coating surfaces showed no sign of abrasion but with only visible adhesive wear. Similarly, scratch tests showed far less material removal in the coating than substrate, showing greatly improved scratch resistance. Additionally, scratch coefficient of friction measured during these tests showed the addition of the coating decreased coefficient of friction to as low as 0.25 compared to the 0.4 of the substrate. The combination of these properties shows that this coating and application method is useful in a wide range of industries.
Effect of Pressure and Temperature on the Performance of Argyrodite Li6PS5Cl0.5Br0.5 Electrolyte for All-Solid-State Lithium Battery
Authors: Dunham Joshua , Frisone Dominic , Amiriyan Mahdi , Hassan Eman , Feng Hu Jung , Farahati Rashid , Farhad Siamak 
Published: January 2022

Abstract
Solid state electrolytes are promising materials for use in lithium-ion batteries for applications in electric vehicles and aircraft. One of the most promising solid electrolytes are the Argyrodite materials, Li6PS5X(X = Cl, Br, I). Among Argyrodites, Li6PS5Cl0.5Br0.5 crystalline material has high ionic conductivity, good processability and excellent electrochemical stability. It is reported in literature that the pelletization pressure and operating pressure and temperature significantly affect the ionic conductivity of argyrodite electrolytes and the cell performance. The focus of this paper is on Li6PS5Cl0.5Br0.5, a crystalline electrolyte material, and the goals are to systematically investigate effects of the pelletization pressure and operating pressure and temperature on the ionic conductivity of this material. The results of this study help to understand the range of pelletization, and operating pressures of all-solid-state lithium sulfur batteries made with Li6PS5Cl0.5Br0.5 crystalline electrolyte material.
Design and Testing of 3D Printed Tissue Scaffolds With Directionally Tunable Stiffness
Authors: Masud Abdullah Al , Arefin Amit M. E. , Chyu Ming-Chien , Egan Paul F. 
Published: January 2022

Abstract
Design and fabrication of beam-based lattices using 3D printing technology have enabled the development of biomedical implants with mechanically efficient scaffolds. For instance, bone tissue scaffolds are engineered implants that could benefit from multi-directional stiffness tuning in relation to the complex loadings of the body. Here, we introduce beam-based lattices with height-adjustable BC-Tetra unit cell designs with different configurations for tuning the elastic modulus along different loading axes. The BC-Tetra unit cell has a tetragonal organization with a square base and adjustable height. Unit cells were designed with a beam diameter of 0.8 mm, porosities of approximately 50% and 70%, and varied unit cell heights for each porosity. Lattices were built during the stereolithography process with E-Shell 600 material that is a biocompatible methacrylic acid-based polymer. Mechanical compression experiments were conducted to investigate the effects of varied BC-Tetra unit cell designs on the longitudinal and transverse elastic moduli of the lattice structures. Mechanical compression testing indicates that the longitudinal elastic modulus of the structures increases with the unit cell height, whereas the transverse elastic modulus decreases. Thus, the adjustment of unit cell height allows tailoring of elastic modulus in multiple directions to ensure implants can adjust the host bone loading while mitigating stress shielding. These results contribute to better design decisions for 3D printed lattice structures with specified mechanical properties that provide new dimensions for biomedical implant design.