bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Powered Wireless Sensor for Risk Assessment: Characterization and Implementation
Authors: Aldawood Ghufran , Bardaweel Hamzeh
Published: February 2023

This article introduces an electromagnetic vibration energy harvester and sensor assembly that is interfaced with a monitoring app for risk assessment of dynamic structures. The stand-alone energy harvester subassembly is used to power an amplitude modulated (AM) radio transmitter and microcontroller circuitry that can wirelessly transmit vibration sensor data using a sensor subassembly. The dual-mass moving magnets of the electromagnetic energy harvester and sensor assembly incorporate a directed magnet by a diaphragm-like moving FR4 spring. The transmitted sensor values are streamed into a PC where signal processing of the data takes place. The designed app can identify the vibration frequency of the sensor with high precision with an error as low as 0.1%. The total energy consumed to transmit a sensor value is approximately 0.9 μJ at an operating voltage of 3 V and minimum operable acceleration of 0.7g [m/s2].
A Hierarchical Approach for the Verification and Validation of Tolerance Analysis Models
Authors: Schaechtl Paul , Schleich Benjamin , Wartzack Sandro
Published: February 2023

Established tolerance analysis methods are capable of predicting the effects of geometrical part variations on the quality of products and hence virtually assuring their functionality. However, assumptions and simplifications are often made, which can lead to decisive uncertainties. To omit a significant effect of these uncertainties on the overall model and on the obtained results, both a virtual assessment of the model as well as an experimental validation are necessary. The current state of the art still lacks suitable methods and metrics to reliably evaluate the results of tolerance analyses. In addition, an approach is needed to investigate and evaluate the effects of uncertainties within the analysis model on the overall model. The aim of this contribution is therefore to derive statements about the suitability and significance of methods and metrics of verification and validation for evaluating simulation models and their feasibility in the context of tolerance analysis. First, general methods and metrics for the evaluation of simulation results are presented. Subsequently, the most promising ones are customized in an unifying approach. The statistical tolerance analysis of a 3-D-printed non-assembly mechanism in motion serves as an explanatory example for highlighting the procedure and the current challenges and constraints. Finally, the findings are critically discussed and as a result, statements about the further need for action are presented.
Investigating the Design of a Soft Robot for Finger Rehabilitation
Authors: Glasgo Nina , Soohoo Mitchell , Han Yen-Lin
Published: February 2023

US National Health Interview Survey in 2018 found that 61 million adults aged 18 and over have disabilities. Physical rehabilitation is often prescribed to people with disabilities during their recovery process to regain their mobility. There are several rehabilitation robots available on the market. Some are made with rigid, stiff materials with limited flexibility and may be uncomfortable for patients to wear for an extended amount of time. Some recently developed rehabilitation robots are made with flexible materials like those found in living organisms, which are characterized as “soft robots”. Soft robots are generally made with polymers and actuated by pressurized gas inside of the polymer structure and potentially will be more comfortable to wear. Unlike most other soft robots with external tubes and pipes for fluid flows, in this paper, we are proposing a soft robot is actuated by heat. Our soft robot is designed by sealing a phase changing material (PCM) inside of several chambers made by polymer structure. When heat is applied, the PCM begins to change phase and the pressure inside the sealed chambers increases and expand the polymer structure to create a movement of the soft robot. In this study, we focus on constructing simulation models using ANSYS Fluent to examine the parameters relevant to our intended design. We also present a prototype to be tested in the future work.
Evaluation of a Cryogenic Air Supply As a Breathable Air Source for a Confined Space
Authors: Yan Lincan , Yantek Dave S. , DeGennaro Cory R. , Srednicki Justin R. , Yonkey Jeffrey A. , Lambie Brandin , Carr Jacob
Published: February 2023

A breathable air source is required for confined space such as an underground refuge alternative (RA) when it is occupied. To minimize the risk of suffocating, federal regulation requires that mechanisms be provided and procedures be included so that, within the refuge alternative, the oxygen concentration is maintained at levels between 18.5% and 23% for 96 hours. The regulation also requires that, during use of the RA, the concentration of carbon dioxide should not exceed 1%, and the concentration of carbon monoxide should not exceed 25 ppm.

The National Institute for Occupational Safety and Health (NIOSH) evaluated the cryogenic air supply’s ability to provide breathable air for a refuge alternative. A propane smoker was used to simulate human breathing by burning propane gas which will consume O2 and generate CO2 and H2O. The rate of propane burned at the smoker was controlled to represent the O2 consumption rate for the breathing of a certain number of people. Two 96-hour tests were conducted in a sealed shipping container, which was used as a surrogate for a refuge alternative. While burning propane gas to simulate human oxygen consumption, cryogenic air was provided to the shipping container to determine if the cryogenic air supply will keep the O2 level above 18.5% and CO2 level below 1% inside the shipping container as required by the federal regulations pertaining to refuge alternatives. Both 96-hour tests simulated the breathing of 21 persons. The first test used the oxygen consumption rate (1.32 cu ft of pure oxygen per hour per person) specified in federal regulations, while the second test used the oxygen consumption rate specified by [1] (0.67 cu ft of pure oxygen per hour per person).

The test data shows that during both 96-hour tests, the oxygen level was maintained within a 21%–23% range, and the CO2 level was maintained below 1% (0.2%–0.45%). The information in this paper could be useful when applying a cryogenic air supply as a breathable air source for an underground refuge alternative or other confined space.
Coupling Smoothed Particle Hydrodynamics With Finite Element Method to Simulate Residual Stresses From Friction Stir Processing
Authors: Balusu Kranthi , Li Lei , Choi Kyoo Sil , Soulami Ayoub
Published: February 2023

Friction stir processing (FSP) is a solid-state material processing technique that locally modifies the microstructure but also induces undesirable residual stresses. A robust numerical model for the FSP can help in mitigating these residual stresses. Heat source models within a finite element method (FEM) framework suffer from inaccuracies. In contrast, smoothed particle hydrodynamics (SPH) model that explicitly captures the material flow near the tool and the associated heat generation is accurate. However, the computational expense of SPH simulations can be prohibitive. In this work, we propose a coupled SPH-FEM framework. SPH is used to accurately model the heat generation near the tool, which is then inserted into the FEM model as a heat source. To verify this proposed coupling approach, a test case is set up with typical FSP conditions, and it is modeled in both SPH and SPH-FEM. The temperature profiles were compared after the simulations had reached steady-state temperatures. The similarity of the temperature profiles from SPH-FEM and SPH validated the proposed coupling approach. This proposed approach achieves the accuracy of the SPH method while potentially retaining the low computational expense of FEM.
A Systematic Literature Review of Passive Energy Consumption Optimisation Strategies in Buildings and Their Selection Criteria
Authors: Balali Amirhossein , Yunusa-Kaltungo Akilu , Edwards Rodger
Published: February 2023

Buildings are essential to the development and sustainability of any society, due to the criticality of their residential, commercial and educational roles. However, the building sector has also been classified as highly energy-intensive, due to its ever-rising annual energy consumption trends. Buildings’ energy consumption rate is in fact expected to increase further over the coming years, due to current trends of global population growth. It is therefore imperative to deduce and implement strategies that would improve the sustainability of energy within the built environment. Taking advantage of passive energy consumption optimisation strategies is an apt alternative in this case. However, the procedure of selecting the best passive energy consumption optimisation strategy, including selection of the passive strategy itself, selection criteria and selection method, has been a challenge for buildings’ experts. The use of Multiple Criteria Decision Analysis (MCDA)/Multiple Criteria Decision-Making (MCDM) approaches have proven useful for aiding the selection of alternatives based on multiple criteria in numerous studies during recent years. However, there are several techniques within the MCDA/MCDM class of techniques, which make the selection process rather convoluted. Therefore, the overarching aim of the current study is to generate the most prevalent passive energy consumption optimisation strategies for buildings, the criteria for their selections and the corresponding MCDA/MCDM techniques that aided such selections. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Procedure for Performing Systematic Reviews (PPSR) were used to conduct the current systematic literature review (SLR). The SLR examined research articles that are domiciled within very popular databases such as Compendex, GEOBASE, GeoRef, Inspec, Web of Science (WoS) and Scopus, based on meticulously constructed keywords. It was observed that limited passive strategies, selection criteria and MCDM/MCDA techniques were considered in the investigated articles, making it a serious gap in the body of knowledge, which needs accurate consideration for future studies. For instance, it was observed that most studies focussed on particular passive strategies such as optimisation of insulation thickness and location, natural ventilation envelope, etc., while other strategies such as thermal bridge reduction, enhancing vapour tightness and natural daylighting are underrepresented. The results of the SLR are hereby provided and discussed in the current study.
Effect of Interleaved MWCNTs Buckypaper on the Mechanical Properties of Non-Crimp Carbon Fiber Composites
Authors: Jadhav Vishwas , Kelkar Ajit D.
Published: February 2023

Carbon fiber reinforced with carbon-based nano-fillers is becoming popular for many applications due to its exceptional properties, such as high strength and stiffness. The matrix toughening is another way to improve the interlaminar fracture resistance. Short, micro, and nano-fillers are used for enhancing matrix properties. One of the challenges of using nanomaterials is that they get agglomerated due to the high aspect ratio and strong intermolecular and dipole-dipole interactions. To overcome the agglomeration problem, researchers have used interleaving sheets typically inserted at various locations through the thickness of the laminate. The present work uses 48 layers, symmetrically arranged of Non-Crimp Carbon fibers prepregs which were oven-cured to fabricate the composite laminates, with and without buckypaper at the midplane. Multi-Walled Carbon Nanotubes (MWCNTs) buckypapers with 45 gsm were used to fabricate nanoengineered composite laminate. Double cantilever beam (GIC), short beam shear strength, and flexural strength were performed as per ASTM 5528-13, 2344-M16, and 790-15 standards to analyze static and dynamic properties. Buckypaper incorporated laminates showed degraded mechanical properties; to enhance these, the lattice structures formed on the buckypaper and composite laminates were analyzed. The results indicate that the composite laminates fabricated using lattice buckypaper structure had better interlaminar strength than those without lattice grid buckypaper.
High Efficiency Manufacturing With a Smart Carbon Fiber End Effector
Authors: Chun Carrington , Guerra-Zubiaga David A. , Bailey Garrett , Bharadwaj Kathryn
Published: February 2023

Advanced industrial assembly lines often utilize large-scale robotic arms such as the Fanuc S 420-F. Such arms, and their end-effectors, are typically constructed from high-strength steel, which gives the systems superior rigidity at the cost of being very heavy. A new cutting-edge composite material, carbon fiber, offers the strength of steel at a fraction of the weight. To improve energy efficiency, this research project analyzed the feasibility of replacing the steel structure in an end-effector with a carbon-fiber composite, in addition to equipping the end effector with revolutionary ‘Smart’ technologies. Simulations performed in Siemens’ Process Simulate Tecnomatix module helped to inform mechanical energy computations for an arbitrary pick and place task and energy cost estimations were analyzed with the end-effector constructed from both steel and carbon fiber. The projected change in energy consumption for performing the pick and place task was then compared to determine the potential benefit of the carbon fiber substitution. In addition to the advanced material use, this research project also investigated the possibility of implementing ‘Smart’ technologies in the custom end effector design to further improve energy efficiency. The proposed smart technology would utilize machine vision to actively direct vacuum pressure to only the necessary suction cups in a pneumatic gripper array. Possible energy savings associated with the smart end effector design were analyzed. Simulation results for a simple pick and place operation showed that the Smart Carbon Fiber End Effector required only 2.22 Kilojoules of energy, compared to the 3.92 Kilojoules of energy needed for a Passive Steel Framed End Effector. Through creation and simulation with Digital Design Tools, the feasibility of combining advanced new structural materials with integrated intelligence was explored to create a revolutionary new end effector design that could reduce the energy consumption for a pick and place task.
Material Characterization of Phase Change Materials for Munitions Safety Applications
Authors: Foltynski Jacek , Franqui Jason , Vasiyschouk Andriy , Mudryy Ruslan , Blecker Kenneth
Published: February 2023

Ammunition packaging is a critical safety component throughout a munitions lifecycle. Packaged munitions are subjected to a series of harmonized Insensitive Munitions (IM) and Final Hazard Classification (FHC) tests that dictate limits on storage and transportation operations. System level IM tests include bullet and fragment impact, fast and slow heating and sympathetic detonations among others. The reaction severity of packaged ammunition to each external stimulus creates the basis for the final hazard classification. Detonations and explosions result in restrictive shipping and storage quantities. Benign reactions result in less restrictive final hazard classifications that allow for improved logistical efficiencies. Significant studies are being conducted to improve insensitivity and hazard classifications of legacy munitions without redesigning the ammunition or energetic material. This work investigates the integration of phase change materials (PCM) into munitions packaging to improve IM reactions during fast and slow heating. Both fast and slow heating are possible occurrences in the military ammunition lifecycle due to vehicle accidents, fuel spills or enemy actions. The materials in question are a solid, wax-like substance that begin to melt at a specific temperature. Once the PCM reaches it latent heat of fusion it acts as a heat sink that can absorb large amounts of energy. This property may help improve cook-off reactions of packaged ammunition that is exposed to an uncontrolled external heat source such as a fuel fire. Limiting and delaying heat transfer to extremely sensitive primary explosives and igniters may allow less sensitive components to burn out and prevent a detonation or explosion. Material testing was conducted to quantify the thermal characteristics of several PCM configurations. A legacy mortar package was selected as the test bed with a focus on the propulsion charge and its ignition train. A numerical model was utilized to identify potential designs for evaluation. Limited free volume created a challenge to fit enough PCM into the required areas needed to achieve the desired result. Full scale heating tests were conducted with an inert munition to collect system thermal data, including interactions of multiple layers of packaging materials. The PCM influenced the thermal response of the legacy packaging system as compared against baseline data. When used in specific locations and quantity for the packaging system in question, the PCM absorbs enough heat energy to show a measurable decrease in munition skin temperature at critical points of interest. The findings show that phase change materials may reduce reaction severity of legacy munitions by influencing heat transfer in designated areas. A robust and economical containment method for PCM is still required for munition applications.
Molecular Dynamics Analysis on the Degradation Mechanism of the Crystallinity and Strength of Grain Boundaries in Heat-Resistant Alloys Under Creep-Fatigue Loading at Elevated Temperature
Authors: Tezuka Shogo , Suzuki Ken
Published: February 2023

In this study, we analyzed the degradation phenomena near grain boundaries that cause brittle intergranular cracking under high-temperature creep loading by molecular dynamics analysis of a bicrystal structure consisting of grains with different orientation. The results show that stress relaxation occurs even under uniaxial stress creep loading with a magnitude of 40% of the yield stress of the bicrystal structure. Furthermore, it was observed that the stress relaxation was accelerated by the combination of grain orientations of the grains constituting the bicrystal structure. This stress relaxation was caused by the activation of atomic diffusion around the grain boundary. In particular, when there is a difference in the elastic moduli of the two crystals forming the bicrystal structure, it was found that diffusion outside the grain boundary is activated. In the crystal with the lower elastic modulus, the diffusion of atoms from the grain boundary to the grain inside was found to occur significantly. Then, it was revealed that the significant decrease in atomic density around the grain boundary reduces the effective strength of the grain boundary and promotes grain boundary cracking due to the decrease in crystallinity around the grain boundary.
Design and Realization of a Double Telescopic Arm End Effector for Multi Format Cell Container Handling Inside of Incubators
Authors: Ameres Valentin , Kostner Ismael , Artmann Lucas , Lueth Tim C.
Published: February 2023

Cell cultivation in life science laboratories is very time consuming due to the increasing amount of required cell lines The process of cell cultivation includes several steps like seeding, renewing cell culture medium, microscopy of cells and checking environmental parameters like temperature, humidity and CO2 content of the ambient air. Control of environmental parameters for optimal growth conditions is achieved by placing cells inside closed incubators. Opening and closing, as well as moving cell containers manually in and out of incubators for microscopy or other tasks can be detrimental to environmental conditions inside the incubator as well as to cell growth in general. In the context of this work, the stem cell proliferation process including cell culture medium change and phase contrast microscopy is automated by an X-Z-portal robot located inside the incubator itself. The portal robot is vertically mounted in front of the incubator shelves. A novel robotic end effector is presented which has two individually controllable telescopic parallel arms mounted on top of a rotating base which enables handling of T75 and microplate cell cultivation containers as well as actuation of push to drain mechanisms and additional modules for cell culture medium change. The proposed end effector concept provides versatility while minimizing footprint and maximizing serviceable incubator shelf space.
Experimental Investigation of Evaporator and Condenser Placement Configuration for Oscillating Heat Pipes
Authors: Castro Osvaldo , Wolk Kieran , Furst Benjamin , Sunada Eric , Roberts Scott , Daimaru Takuro , Kuo Jim , Bellardo John
Published: February 2023

In this work, we explore two different Oscillating Heat Pipe (OHP) evaporator-condenser placement configurations, and investigate and quantify the effects on thermal performance. The proposed study focuses on two different OHP evaporator-condenser configurations with a change in adiabatic length.

One of the challenges in OHP literature is the variety of experiment setups, (e.g. varying condenser, evaporator, and adiabatic lengths, heat input) which makes it difficult to compare results directly. To quantitatively compare thermal performance, a (or a set of) standardized metric(s) must be used. Therefore, we define a standardizing metric to quantify OHP’s ability to conduct heat that can be used across multiple experiments and setups.

This study was conducted on an additively manufactured flat-plate AlSi10Mg OHP which has a channel diameter of 1.4 mm, 22 turns, and a plate size of 200 mm × 90 mm × 4 mm. Both the evaporator and condenser are rectangles with contact areas of 46 mm by 78 mm. The OHP was charged with R134a with a 45% filling ratio. In these tests, the location of the evaporator was fixed, while the placement of the condenser is varied such that the adiabatic length ranged between 4 mm to 94 mm. The condenser temperature was maintained between 10°C to 25°C and the heat input ranged between 20W to 50W.

The results showed that a reduction in adiabatic length increased the thermal conductivity. To quantify the thermal performance, the thermal conductivities of an empty and charged OHP were determined for each placement configuration, then a thermal conductivity ratio of charged and empty OHP can be determined to quantify the improved performance. For an adiabatic length of 4 mm, we observed that the OHP’s ability to conduct heat was 40 times more effective when compared to an empty OHP. It was also observed that the OHP’s ability to conduct heat was 9 times more effective when compared to an empty OHP for an adiabatic length of 94 mm. We conclude that the area outside the evaporator-condenser that is neither heated nor cooled, called the reservoir, significantly influenced the thermal performance. The OHP with a shorter adiabatic length increased the reservoir in the condenser region which showed higher thermal performance. In this placement configuration, the reservoir essentially acted as an extension of the condenser. This is a favorable condition where the subcooled liquid slugs re-enter the condenser section which affects heat transfer drastically. Thus, the placement of the evaporator-condenser will influence OHP performance due to the reservoir and warrants future work.
Development and Implementation of a High-Temperature FDM Machine for Additive Manufacturing of Thermoplastics
Authors: Billings Christopher , Saha Mrinal , Liu Yingtao
Published: February 2023

In recent years, the reduction in the entry cost of additive manufacturing has allowed for a paradigm shift in research and development methodologies worldwide. Explicitly focusing on FDM-based manufacturing and its role in the e-design process, this technology has dramatically reduced the idea to market timeframe compared to traditional manufacturing. However, the most significant drawback to this change is that these technologies are currently limited to low load and thermally static applications based on the material capabilities of many FDM machines. The exception to this rule is the few machines capable of printing with materials such as ULTEM and PEEK with thermally controlled chambers to address the above problems. Unfortunately, these machines are generally out of reach for most due to their cost and proprietary materials and software. This paper will outline the development and construction of a printer capable of working with materials at 500 degrees centigrade by utilizing a water-cooled dual extrusion system. This system will be operating inside a closed chamber capable of holding temperatures constant at 100 degrees centigrade. The entire system was manufactured for only 4% of the cost of current market offerings. The printer is based on a market available platform that has been upgraded to include a direct drive water-cooled dual extrusion head. The chamber heating is handled by a 110-volt platform that pairs with secondary heaters to control the interior temperature. The entire motion system is enclosed to control thermal swings, and all electronics are exterior mounted and cloud-based for monitoring and operation. In addition, this printer allows the fabrication of designs that produce parts that are up to six times stronger, three times more heat resilient, and three times less water absorbent. The reduction in entry cost to work with engineering-grade thermoplastics will significantly increase the adoption rate of additive manufacturing in small businesses and design shops.
Selection of Industry 4.0 Competencies for Implementation in a New Mechanical Engineering Undergraduate Program
Authors: Muci-Küchler Karim H. , Emami Anahita , Jimenez Jesus
Published: February 2023

The implementation of Industry 4.0 tools and technologies in many companies coupled with the impact of those tools and technologies in the product design and development process is creating a demand for engineering graduates that have basic competencies (i.e., knowledge, skills, and abilities) related to Industry 4.0 when they join the workforce. This paper presents key Industry 4.0 competencies that were selected for a new mechanical engineering program at Texas State University. For each competency, the level in Bloom’s taxonomy that students are expected to attain at the time of graduation is defined taking into consideration that the implementation of Industry 4.0 tools and technologies is a multidisciplinary endeavor that involves professionals from different majors. The paper also provides information about the implementation plan that will be used to incorporate the competencies selected in the undergraduate curriculum.
Experimental Results for Large Particle Separation From Non-Newtonian Slurries Using Tapered Bump Arrays
Authors: Bamberger Judith Ann , Pease Leonard F. , Serkowski Jason E. , Minette Michael J. , Burns Carolyn A.
Published: February 2023

Lateral displacement arrays are useful for separating particles such as blood cells and sand from carrier fluids. These arrays consist of staggered posts, which allow smaller particles to follow streamlines and larger particles to flow around the posts and migrate to one side. This migration increases the particle concentration in one direction and depletes the particle concentration in the other direction allowing particle separation to occur.

Experiments were conducted to separate large particles in non-Newtonian yield stress slurries using tapered bump arrays. The non-Newtonian slurry used was composed of a bentonite kaolin blend with the inclusion of larger diameter particles. These experiments were conducted to evaluate the performance of particle separation using a tapered array of staggered posts as configured in a bump array for non-Newtonian yield stress slurries, an application that has not been explored experimentally. The results of these experiments are described. This information could be applied in industrial settings such as separation of particles from nuclear waste slurries including those to be processed at the Hanford site, where removing large particles from waste streams is important to processing.
Assessing Severity of Cyber-Attack Threats Against Cyber-Manufacturing Systems
Authors: Espinoza-Zelaya Carlos , Moon Young
Published: February 2023

The threats of cyber-attacks against Cyber-manufacturing systems (CMS) pose production manager with a unique challenge. The timing, target, severity of their occurrence is all uncertain and yet decisions need to be made in real time to ensure the achievement of production goals under their advent. This paper proposes a systemic approach to estimate threat severity in three different dimensions, (i) disruption potential, (ii) total economic impact, and (iii) non-tangible losses.

A model resilient testbed CMS is presented, which is a system with prevention, detection, redundancy, and recovery mechanisms implemented against cyber-attacks. We evaluate the potential threat by analyzing the state of production factors and the characteristics of the potential responses that the system has set in place. The severity of the attack cannot be defined in advance given that the level of disruption that can create is not an absolute value but rather dependent on the state of the system at it time of its occurrence. To address this uncertainty, we utilize an expected value equation in which we take the worst-case scenario and take actions to ensure the system remains resilient. Decisions are taken to minimize cost while ensuring the fulfillment of the production goals.
Design of Low-Level Hardware for a Multi-Layered Control Architecture
Authors: Kogelis Madeline , Fuge Zachary J. , Herron Connor W. , Kalita Bhaben , Leonessa Alexander
Published: February 2023

In this work, the low-level (LL) hardware for sensor collection, motor input, and networking with a high-level (HL) controller is presented for robot systems which utilize linear series elastic actuators (LSEAs) for joint actuation. In multi-joint robotic systems, LL controllers rely on sensor readings to control each joint and communicate the obtained information to the HL controller. This research outlines the hardware design of two printed circuit boards (PCBs), as well as the use of an EasyCAT PRO board for communication. An in-house sensor interface shield is designed as an extension of the TM4C123GXL TIVA microcontroller launchpad and another in-house shield connects to the AZBDC12A8 analog servo drive, or rather, the motor controller. These PCBs allow for sensor integration with circuits that route, filter, or manipulate data obtained from the sensors. The goal of the sensor interface shield is to interface between sensors and the microcontroller. The sensor board takes readings from a force sensor, absolute encoder, quadrature encoder, as well as adjusting the pulse-width modulation (PWM) signal that is sent to the motors. The main purpose of the motor shield is to supply power, route the PWM input, and filter the current output of the motor. The final designs for both the shields are built in the PCB design software Eagle. Overall, these boards will allow for better sensor integration for LL controllers which interface with LSEA driven multi-joint robotic systems.
Mechanical Design Upgrade of Kinematically Reconfigurable Humanoid, HART
Authors: Sohn Kiwon , Wisdom Jordaine , Sharpe Ethan , Robinson James , Tatoglu Akin
Published: February 2023

The continued development of HART (Human Assistive RoboT) is presented in this paper. HART has been designed and built by ART (Assistive Robot Team) in University of Hartford since 2017. To enable the robot to manipulate various control inputs of off-the-shelf vehicles with different sizes and structures in the market, HARTs mechanical design was focused on the achievement of kinematic re-scalability as its main technical design requirement. In this study, the mechanical design upgrade which can increase the robots power and dexterousness to control the steering wheel of the assigned vehicle is mainly described. For this, the third arm which is newly designed with passive joints and expendable links is built and added to HART. Next, HARTs new sensor head which is also redesigned for advancement of its perception capability is introduced in this paper. Lastly, the upgraded robot is tested and evaluated in human-centered environments which include both indoor and outdoor task spaces.
NES3: A Ship-Consensus Double-Layer Blockchain System in New Energy Ship Supervision Scenario
Authors: Yan Gang'ao , Xiao Youan , Wang Tengfei , Li Zhuo
Published: February 2023

As the world’s attention to environmental protection and carbon emissions continues to improve, the number of new energy vessels has increased, and the management requirements and pressure on new energy vessels are getting bigger. Due to the ships’ difficulty of network communication and its high cost, blockchain-based management systems usually do not make ships a part of the scope of consensus and become less certain reliable. To solve this problem, this paper proposes a New Energy Ship Supervision System (NES3) based on a double-layer blockchain, which incorporates ships into the consensus layer to enhance robustness. To ensure the authenticity of ship data, a simplified mesh blockchain is formed among ship nodes, in which only the block heads are synchronized by Simplified Random Grouping Consensus (SRGC) algorithm proposed in this paper. The node of the strong consensus layer is connected in the form of an alliance chain, using the real-time data of the ship to monitor ship status, using the group consensus results, data summary messages, and audit data uploaded by the weak consensus layer for cross-validation, and perform “post-clearing” mechanism, through which the system increases the cost of tampering with data, improves the enthusiasm of ship nodes, and promotes data security. Research shows that the system can ensure reliable data flow with low data volume in the scenario of high network delay and strong ship node dynamics and achieve effective ship supervision.
Dynamics of Periodic Sandwich Beams
Authors: Farzaneh Joubaneh Eshagh , Ma Jihong
Published: February 2023

Sandwich beams are commonly used in vibration absorption applications due to their inherent properties. To further mitigate vibration, metamaterials with periodic properties or periodic resonators are widely incorporated as composite cores to create phonon bandgaps in sandwich beams. However, the effect of periodicity in face sheets of the sandwich beam has been sporadically explored. This paper parametrically investigates the effect of the subunit cell size and different periodicity for top and bottom face sheets on opening bandgaps that can filter transverse and longitudinal waves individually or simultaneously. Structures can be protected from both transverse and longitudinal waves using such mechanisms by enhancing the coupling effect between transverse and longitudinal modes within sandwich structure.
Sliding Wear Behavior of Electron Beam Melted (EBM) Ti6Al4V
Authors: Bin Abdullah Mohammad Sayem , Mamidala Ramulu
Published: February 2023

The practicable application of electron beam melted (EBM) titanium parts requires acceptable mechanical, fatigue, and tribological properties. The current literature is still lacking enough investigations on the tribological properties of EBM titanium. This paper presents the preliminary results and analysis of the dry sliding behavior of electron beam melted (EBM) Ti6Al4V in as-built and machined conditions. To understand the dry sliding behavior at different built orientations, rotary abrasion tests have been conducted on EBM Ti6Al4V specimens built at three built orientations, i.e., 3°, 45°, and 90°. EBM fabricated Ti6Al4V specimens were subjected to rotary abrasion against alumina particles up to 4000 cycles. The mass removal was recorded. The wear tracks generated on Ti6Al4V specimens were inspected through scanning electron microscopy, optical microscopy, and optical 3D profiler. The wear-induced microstructure and hardness variation have been investigated. Experimental results show that the dry sliding wear behavior of EBM Ti6Al4V is influenced by built orientation due to process-induced surface asperities and hardness. Machining significantly increases wear resistance depending on built orientation, and offsets wear anisotropy. The wear mechanism is discussed as well.
Numerical Study of Erosion Wear on the Disc of a Butterfly Valve With Laminar Particle-Laden Flows in a Horizontal Pipeline
Authors: Ayala Orlando M. , Ayala Orlando F. , Villalba Ricardo
Published: February 2023

Butterfly valves are used in many processes where they mostly provide on-off control services. Many industrial processes involve fluid flows carrying particles through pipes where butterfly valves are installed. The presence of those particles produces unavoidable erosion on the valves and its study is of great importance. In this paper a numerical study of the erosion wear generated in the disc of a butterfly valve is presented. A laminar flow of water with solid particles was used. The particle-laden flow was allowed to interact following a oneway coupling. The particles felt the gravity force in the horizontal pipeline and when interacting with the pipe walls they were let to bounce right off. The gravitational effect has not been incorporated in previous studies of erosion wear in butterfly valves. To analyze how the particle-fluid interaction behavior and the gravitational force modify the erosion wear pattern, the particle Stokes number (St) and the dimensionless particle fall velocity (Sv) were varied. Without considering gravity (Sv = 0), the dimensionless erosion rates were found to reach their lowest values when St < 1. This was due to the fact that at those Stokes numbers the fluid controls the particle motion, and it moves them away from the disk when close to it. It was also found that at St >> 1 the erosion rates remain constant because the particles maintain their initial dynamics due to their higher inertia. It appears to be that the Stokes number value of one is a critical point. Similarly, when Sv is not zero, it was observed that the dimensionless particle fall velocity value of 10 appear to also be a critical point. For Sv << 10, the behavior of the impact velocity, impact angle and erosion rate were similar to the ones described of the previous study without gravity. For Sv ≥ 10, the behavior of the impact velocity, impact angle (and therefore the erosion rate) were affected by how the particles interacted with the pipe walls prior to reaching the butterfly valve disc. For very small values of St and very large values of Sv, the particles did not even reach the disc. The magnitudes of dimensionless impact velocity and impact angle have lower values at Sv < 10 and higher values at Sv > 10, thanks to the fact that gravity increased the particle velocity and forced them to bounce with the pipe before hitting the valve. For St∼1 and Sv > 10 the impact velocities and erosion rates present maximums, as a consequence of gravity transferring energy to particles as they bounce through the pipe, and to the high velocity flow near the center of the pipe that also added energy to the particles that approached it.
Investigation of the Leading-Edge Erosion of Wind Turbine Blades Using Multivariant Analysis Method
Authors: Alajmi Abdullah F. , Ramulu M.
Published: February 2023

With the vast development in the wind energy industry, new climates that might be considered harsh on wind turbines are being investigated. One such harsh climate is the desert and arid climate with the high frequency of sandstorm occurrences. During a sandstorm, sand particles of different sizes and shapes collide with wind turbine blades at different angles of attack and impact velocities, causing enormous damage, especially at the leading-edge area. The leading-edge erosion causes a drastic decrease in the turbine’s overall efficiency and, consequently, the amount of energy produced. In this paper, a multiple regression statistical study was conducted to investigate the effects of variables such as air pressure (consequently the particle impact velocity), erosion duration, and the angle of attack. These three variables were used to imitate the conditions during sandstorms closely. The outcome of the erosion process is measured in terms of mass loss and depth of erosion scars. The resulting damage from the erosion process was analyzed using the Analysis of Variables (ANOVA) method. It has been found that the angle of attack has a significant effect on the erosion behavior, with the most severe damage occurring at a 0° angle of attack for both the amount of mass loss and the depth of erosion scars, while the lowest amount of damage occurring at a 10° angle of attack. Similarly, increasing impact velocity and erosion duration caused the most severe damage, and these variables were used to characterize the behavior of the leading-edge erosion of wind turbine blades. Therefore, designers of wind farms in the desert must bear in mind that it is of extreme importance to study probability of sandstorms occurrence, their average duration, their occurrence frequency, and the particles’ velocity.
Entropy Generation Analysis on a Thermoelectric Generator in an Exhaust Automotive Line With Porous Media
Authors: Buonomo Bernardo , di Pasqua Anna , Manca Oronzio , Nappo Sergio
Published: February 2023

In the present paper, an entropy generation analysis on a 2D steady state problem in convective regime of an aluminum foam partially and totally filled channel with an external TEG element is solved in numerical way. The channel has a length of 272 mm and a height equal to 60 mm; instead, the TEG is characterized by a length equal to 65 mm and by a thickness of 8.5 mm. The numerical analyses are accomplished with the assumption of the local thermal equilibrium (LTE) model in order to consider the metal foam presence. The working fluid is exhaust gas characterized by the same properties of the air in correspondence to the TEG upper surface temperature. The TEG is considered as a solid component characterized by an internal energy generation. The thermophysical properties are assumed temperature independent. Ansys-Fluent code is employed in order to resolve the governing equations for exhaust gas, metal foam and TEG. Different exhaust gas mass flow rates on the inlet section are assumed. Several thicknesses of aluminum foam values are employed. The porous media are characterized by a porosity from 0.90 to 0.978 and number of pores per inch (PPI) equal to 5, 10, 20, 40. Results are given in terms of global entropy generations related to the thermal and viscous effects.
Design and Optimization of a Single DOF Anthropomorphic Gait Rehabilitation Device With Passive Branch Chain
Authors: Wang Xiaoyu , Han Xu , Song Ci , Zhao Ping , Cai Mei
Published: February 2023

In this paper, a single degree of freedom (DOF) anthropomorphic gait rehabilitation mechanism with passive branch chain is proposed and optimized. First, the dimension parameters of the mechanism are designed. Taking the normal gait trajectory as the target, 1-DOF Watt-I six-bar mechanism driven by a uniform motor is adopted as the motion executer, and its path synthesis is carried out. Then, the lightweight design of the lower limb rehabilitation mechanism is implemented. A three-dimensional design model of the six-bar linkage is established, which is imported into ANSYS Workbench for static force analysis and topology optimization. Then, a 2-DOF passive chain is designed and imposed into the mechanism for a better dynamic and kinematic performance. In the end, a prototype of the 1-DOF six-bar gait rehab device with passive chain is built, and experiments are conducted using motion capture system to obtain the trajectory. The results show that the optimized mechanism can well simulate the motion of normal human gait trajectory, which verifies the effectiveness of the mechanism and the optimization method.
Characterization of 3D Printed Single Filament Carbon Fiber Epoxy Composite
Authors: Mondal Anirban , Saha Mrinal , Maity Kuntal , Altan M. Cengiz , Liu Yingtao
Published: February 2023

The conventional composite fabrication processes, such as hand lay-up, autoclave, vacuum-assisted resin transfer molding, and filament winding, hinder the prospect of future development and application due to expensive mold fabrication, limited part geometries, and lack of repeatability. An extrusion-based additive manufacturing technique, such as direct-ink-writing (DIW), undermines the limitation of conventional manufacturing processes, which opens up the horizon of multi-material parts fabrication cost-effectively. This research investigates 3D printed single filament printing and characterization under tensile loading. In 3D printing, a single filament representative volume element (RVE), which upon stacking a series of RVE layer-by-layer in sequence, forms a 3D object. Thus, the deformation behavior of a single filament and the load transfer mechanisms to neighboring filament through the interface plays a critical role. An adequate understanding of single filament’s failure mechanisms and the contribution of interfaces in a 3D printed multi-filament object is yet to be understood. This research extensively focuses on developing a fundamental understanding of the behavior of a 3D printed single filament under tensile loading. The DIW ink composite sample comprises milled carbon fibers, two-part epoxy resin, silica fillers, and plastic additives.
Nonlinear Dynamics of a Planar Mechanism With Cam and Clearance
Authors: Yousuf Louay S. , Marghitu Dan B.
Published: February 2023

A planar mechanism with three moving links is connected to a cam. The investigation of the dynamic simulation of crank arm and connecting rod in the existence of clearance in cam follower system is studied against cam speeds. Nonlinear response for crank arm, connecting rod, and roller follower is simulated at various clearances and various cam speeds. Nonlinear dynamic tool are used to quantify local Lyapunov exponent. The periodicity of nonlinear response is detected using phase-plane diagram, power density function, and Poincare’ map. Solidworks program is needed in the simulation of point linear displacement. The impact and friction are considered in SolidWorks based on the value of sliding contact velocity and kinetic coefficient of friction. The impact of coefficient of restitution is investigated between the cam and the follower and between the follower and its guides. The trend of the nonlinear response of the crank arm and the connecting rod are discussed.