bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generative Design and Topology Optimization of Disk Brake Floating Carrier
Authors: Zefinetti Filippo Colombo , Regazzoni Daniele , Rossoni Marco 
Published: February 2021

Abstract
In the last past years, computer-aided technologies to improve existing products by widening the design space have been largely investigated. Topology optimization and generative design are two of the most representative technologies of such kind. This paper aims at investigating the use of generative design and topology optimization techniques to improve products whose design has not changed radically over the years. The product under investigation is a disk brake floating caliper that is the most common solution for commercial vehicles. In general, increasing the stiffness of the floating caliper while keeping its weight under control is desirable both from performance and fuel consumption point of view. The solution here proposed aims at exploiting two new ways to approach the engineering design process and evaluate which one is more suitable for problems of this kind. Starting from the original carrier shape, acquired with laser scanning, the two technologies have been applied on the same initial conditions. The initial design space volume corresponds to the acquired shape, the loads and the constraints for the simulation have been drawn reasonably to resemble the actual operating conditions. Keeping the input parameters constants, two different off-the-shelf software packages have been used to perform the computation and with the objective of maximizing the stiffness of the carrier while reducing its mass. The comparison and the improvements on the final designs have been drawn taken as reference to the original caliper.
Manufacturing of Porous Polydimethylsiloxane (PDMS) Plates Using Solvent Evaporation Induced Phase Separation Technique
Authors: Abshirini Mohammad , Altan M. Cengiz , Liu Yingtao , Saha Mrinal C. , Cummings Laura , Robison Thomas 
Published: February 2021

Abstract
This paper presents the fabrication and characterization of porous polydimethylsiloxane (PDMS) plates. The framework for obtaining porous PDMS is based on the solvent evaporation induced phase separation technique. A mixture of PDMS, water, and tetrahydrofuran (THF) with different concentrations is prepared. The three phases are stirred to reach a highly stable and viscous solution. The THF and water phases are evaporated during a curing cycle by applying a stepping heat treatment. The porous PDMS sheets with a wide range of pore sizes are fabricated by controlling the ratio of water to THF in the mixture. The confocal microscopy images are used to characterize the average pore size and the pore size distribution in the structures. Dogbone samples following the ASTM standard D412 are cut from the porous plates by utilizing a designed cutting die and mechanical press. The specimens are tested under tensile loading to evaluate the effect of the pore size on the mechanical properties of the porous structure. The results demonstrate the ability of the proposed solvent evaporation method to control the stiffness of the porous structure by changing the non-solvent to the solvent ratio in the mixture.
Low Cost Markerless Motion Capture Systems: A Comparison Between RGB Cameras and RGB-D Sensors
Authors: Vitali Andrea , Regazzoni Daniele , Rizzi Caterina , Lupi Giorgio 
Published: February 2021

Abstract
In the last years, the advent of low-cost markerless motion capture systems fostered their use in several research fields, such as healthcare and sport. Any system presents benefits and drawbacks that have to be considered to design a Mocap solution providing a proper motion acquisition for a specific context. In order to evaluate low-cost technology, this research work focuses on the evaluation of the accuracy of two categories of devices: the RGB active cameras and the RGB-D, or depth sensors devices. In particular, GoPro Hero 6 active cameras and Microsoft Kinect v2 devices have been selected as representative of the two categories. In particular, this work evaluates and compares the performances of the two systems used to track the position of human articulations. The two devices have been chosen among those available on the market after a state of the art has been completed. Before starting with the campaign of acquisition, the number of sensors and their layout have been designed to optimize the acquisition with both mark-less Mocap systems. Their comparison is based on a list of specific movements of upper and lower limbs. Each movement has been acquired simultaneously, to guarantee the same test conditions. The results have been organized, compared and discussed by evaluating performances and limitations of both solutions related to specific context of use. Conclusions highlight the best candidate technology.
Assessment of Elevator Risks and Code Requirements Associated With Slip, Trip and Fall Hazards
Authors: Bress Thomas , Kennedy Eugenia , Guttag Mark 
Published: February 2021

Abstract
In previous work, the hazards associated with elevator door closures were identified and analyzed. Using the National Electronic Injury Surveillance System (NEISS) database of the U.S. Consumer Product Safety Commission (CPSC), incidents associated with door strikes were identified between the years 1990 to 2017.
This current effort focuses on elevator slip, trip and fall hazards. The ASME A17.1 Safety Code for Elevators and Escalators requires that elevator systems be equipped with leveling devices to vertically align the car platform sill relative to the hoistway landing sill to attain a predetermined accuracy. Even with the leveling safety requirements, slip, trip and fall incidents for passengers exiting or entering elevators are known to occur. This paper will analyze elevator slip, trip and fall hazards using injury records from the NEISS database from 1990 to 2019. Relevant elevator incidents were extracted from this dataset through manual inspection of the text-based description fields of all elevator-related incident records found in the NEISS dataset from this time period. National projections of elevator incidents were then calculated from this extracted dataset and trended for the entire time period of 1990 through 2019. The age and sex distributions of these national projections were also analyzed. These projections and trends are then discussed in the context of ASME A17.1 requirements intended to mitigate the risks of injuries when entering or exiting an elevator.
Real-Time Prediction of Temperature Distribution in Additive Manufacturing Processes Based on Machine Learning
Authors: Bayat Sharareh , Mohseni Mohammad , Behnami Delaram , Abolmaesumi Purang 
Published: February 2021

Abstract
Simulation tools improve various aspects of the additive manufacturing process, however, they come with an undesirable computational time for real-world applications. Finite element analysis (FEA) that solves partial differential equations (PDE) presents promising capabilities in simple additive manufactured components as an expository problem. Yet, PDE-based solutions take significantly long CPU time due to a large number of timesteps required to simulate an additively manufactured part. With modern machine learning (ML) capabilities, a new shift towards integration of FEA and ML has been introduced, where ML algorithms emulate the behavior of the time-consuming PDE-solver for real-time analysis of PDE in a given application. In this paper, we present a deep learning (DL) model that can substitute the thermal analysis of the additive manufacturing process. The training data is obtained by sampling the established physical model’s behavior over different temperatures, cooling rates, and part’s geometries. The network architecture is composed of a Long Short-Term Memory (LSTM) to model the temporal sequence of deposition temperatures derived by PDEs. The reported R2 value on validations data is 97%, while the Mean Absolute Error (MAE) is 0.04. This paper compares the performance between the PDE and DL forecast for the thermal results. We show DL models are promising for simulation of the additive manufacturing process, and can be reliable alternatives for computationally-expensive FEM tools.
Bearing Fault Detection and Classification: A Framework Approach
Authors: Melgarejo Agudelo Carlos Fabián , Blanco Rodriguez John Jairo , Maradey Lázaro Jessica Gissella 
Published: February 2021

Abstract
Bearings are the major components in rotary machinery and very used in the industry. The time for bearing failures identification before interrupting operation or affecting product quality is the basis for most predictive maintenance programs. Taking readings, keeping history of failures and evaluating these results in the operation of rotating equipment on a regular basis, allows to detect possible failures before they become catastrophic. In this way, the damages or defects that are detected before a failure occurs, reduce the repair costs and the time that a rotating machine will be inactive. The bearing failures can generate losses due to machine downtime, unwanted vibration, noise and damage of other components, but if they are detected in time, repair costs and downtime are minimal.
This article shows in detail the different detection and classification techniques most used to identify bearing failures such as vibration analysis, artificial neural networks (i.e ANN), convolutional neural networks (i.e CNN) and support vector machine (i.e SVM) and the relevant features of each detection technique.
Numerical Modelling of Mineral-Slurry Like Flows in a 3D Lid-Driven Cavity Using a Finite Element Method Based Tool
Authors: Peralta Sergio , Córdova Jhon , Celis Cesar , Maza Danmer 
Published: February 2021

Abstract
A finite element method (FEM) based tool is used in this work to numerically modeling mineral-slurry like flows in a 3D lid-driven cavity. Accordingly, the context in which the referred FEM based tool is being developed is firstly emphasized. Both mathematical and numerical models utilized here are described next. A special emphasis is put on the flow governing equations and the particular FEM weighted residuals approach (Galerkin method) used to solve these equations. Since mineral-slurry flows both featuring relatively low flow velocities and containing large amounts of solid particles can be accounted for as laminar non-Newtonian flows, only laminar flows are discussed here. Indeed both Newtonian and non-Newtonian laminar flows are numerically studied using a 3D lid-driven cavity at two different Reynolds numbers. Two rheological models, power-law and Carreau-Yasuda, are utilized in the non-Newtonian flow simulations. When possible, the numerical results obtained here are compared with other numerical and experimental ones available in open literature. The associated averaged discrepancies from such comparisons are about 1%. The results obtained from the numerical simulations carried out here highlight the usefulness of the FEM based tool used in this work for realistically predicting the behavior of 3D Newtonian and non-Newtonian laminar flows. Multiphase turbulent flows including fluid-particle interaction models will be considered in future developments of this tool such to allow it properly representing the entire mineral-slurry transport phenomenon.
A New Electrode Design for Constant Volume Combustion Chamber
Authors: Shaffer James , Askari Omid 
Published: February 2021

Abstract
The current method of achieving center chamber ignition in the Plasma Combustion Research Laboratory’s (PCRL) Constant Volume Combustion Chamber (CVCC) utilizes either a standard or modified spark plug. The standard spark plug achieves a representation of side wall ignition (similar to a combustion engine) while modified sparkplugs have an extended electrode to allow for a center camber ignition. Two of these modified spark plugs are placed on both sides of the chamber and can effectively seal and isolate the chamber from the electrode. However, the process of welding electrode material to the spark plug is time consuming and requires a large number of modified electrodes to effectively test multiple different spark gap sizes. Also, the process of cleaning the electrode after experimentation shortens the electrode over time with no method of compensation other than creating a new electrode. The new electrode design aims to reduce the structural weakness by removing the welded joint as well as allowing for linear adjustment between testing while remaining firm during testing. The new design presented utilizes high-temperature epoxy, ceramic and grafoil seals to make adjustments easy and precise. The design was analyzed, prior to building and testing, based on the stress induced from the sealant, the total rated voltage, the rated temperature, and the fracture stress of the ceramic material. The stress induced in the electrode device was analyzed with FEA and the results were found to be within the limits of the material in terms of the compressive and fracture strength. The maximum voltage was found to be around 30 kV. The design is tested with 3 different electrode sizes where the largest electrode of 1.3 mm (0.05 in) has the same diameter as the current experimental set up. Two smaller electrodes 1 mm and 0.5 mm (0.04 in and 0.02 in) are tested as well to show the range and capabilities of the new system. The voltage and current data of the new and old system are compared and are found to be statistically similar within a 90 percent confidence level. The new electrodes is also compared to the previous system in terms of electrical resistance, the peak power each system can provide to the plasma, the visual shape and duration of the plasma through high speed photography. The range of operation for a successful design includes pressures from 20 mTorr to 40 atm, temperatures up to 280 C, and voltages up to 25 kV.
Development of Educational Mobile Soccer Platform Teaching Mechanical Design and Fabrication for Mechanical Engineering
Authors: Lee Hyun Jae , Sim Yu seop , Park Hwi Jin , Park Hoon Min , Yi Hak 
Published: February 2021

Abstract
The mobile platform is an attractive educational tool that has brought to myriad effective benefits for a variety of the application fields. Furthermore, application of the mobile platform to engineering education has greatly assisted the engineering students’ firsthand experiences in college. However, most of the robotics classes offered today are concentrating on mechatronics and software education. For the advancement, this paper develops the mobile platform for the effective curriculum in teaching design and fabrication of robots in the house. The design of the proposed mobile platform bases on the knowledge of the majors subject from mechanical engineering. Through the dynamic simulation, the possibility of an introduction of the developed platform to robotics education is verified. Dynamic simulation experiments with the maximum velocity and acceleration of this system are carried out to check the application for educational purposes. As a final step, components of the platform are fabricated and assembled.
Numerical Study of the Effects of Confined Airfoils Usage in High Bypass Ratio Turbofan Engines
Authors: Aguilar Rene , Celis Cesar , Pontes Marcio 
Published: February 2021

Abstract
Turbofan engines are the main power plants used in the commercial airline industry. Increasing the bypass ratio (BPR) in turbofan engines enhances their propulsive efficiency and reduces both noise and harmful gas emissions. Over the years the aero engine industry has devoted huge efforts and enormous amounts of money to improve turbofans’ propulsive efficiency through the increase of their BPR. Based on the current technology however, there is a practical limit to how much BPR can be increased before significant penalties associated with increased both engine weight and nacelle drag erode the benefits. This work numerically studies thus the benefits of using confined airfoils in the engine bypass flow region to counteract the turbofan engine weight and alleviate the efforts over the aircraft wing structure. Accordingly, a description of the proposed engine-airfoils arrangement, relative dimensions and airfoils adequate placement inside the engine bypass duct is initially presented. Two different flight conditions, take-off and cruise, are numerically assessed next using computational fluid dynamics (CFD) based approaches to characterize the particular bypass flow behavior. The numerical work includes the study of engine configurations similar to those used in long-range aircraft. A structured multi-domain mesh, in conjunction with both Reynolds-average Navier Stokes (RANS) and steady-state mixing planes approaches, are used in the numerical model utilized. The main results indicate that using confined airfoils produces substantial lift respect to the engine weight. Engine weight reductions of up to 23% are observed because of the use of confined airfoils in the engines bypass ducts.
Investigating the Design and Manufacture of PneuNet Actuators As a Prosthetic Tongue for Mimicking Human Deglutition
Authors: Araya Francis Darmont , Radhakrishnan Pradeep 
Published: February 2021

Abstract
The number of Total Glossectomy cases in the United States is seeing an increasing trend as per the Nationwide Inpatient Sample Database. Patients, who have undergone such aggressive surgical procedures, have extensive limitations performing basic oral functions such as swallowing (deglutition), eating and speaking. Current rehabilitation prostheses do little in restoring the functionality of the original tongue. This is true especially in deglutition, which is necessary to transfer a bolus to the esophagus. Such patients need advanced prosthetic devices and through this research, investigations into potential solutions for prosthetic tongues to aid in deglutition were carried out. Different designs were considered and based on a decision matrix, PneuNets (pneumatic networks) were adopted as the foundational basis for generating prosthetic tongue designs. Several prototypes were fabricated that used the Fused Filament Deposition process for producing the mold and silicone Eco-flex 00-30 for producing the mechanism. The resulting mechanism was powered using a pneumatic input and kinematic data was collected. Details from literature review, design iterations, simulations, validation processes, manufacturing challenges and conclusions will be discussed in depth in this paper.
Comparison of Epoxy Coating Degradations Under Impingement Flow and Stationary Immersion
Authors: Vedadi Amin , Parvej M. Subbir , Wang Xinnan , Wang Yechun 
Published: February 2021

Abstract
Offshore wind turbines are considered as a reliable source of electricity generation. However, due to the large cost of the construction and installation of offshore wind turbines, most wind turbines are designed to operate for more than 20 years. One of the biggest issues which causes a severe damage to the construction of wind turbines is the existence of a very corrosive environment including large mechanical loads applied to the construction by the waves and the high concentration of salt and other chemicals in the sea water. The construction of offshore wind turbine can be divided into four main regions based on the types of exposure to the water and the corrosive environment, including submerged zone, tidal zone, splash zone, and atmospheric zone. In this study, experiments were conducted to compare the impact of impingement flow of 3.5 w.t.% NaCl solution on the epoxy coating samples to the exposure of the same type of samples to a stationary 3.5 w.t.% NaCl solution. Those two exposure conditions correspond to the environments at the top and the bottom part of the submerged zone of offshore wind turbines respectively. Electrochemical Impedance Spectroscopy (EIS) method was used to monitor the degradation of organic coatings. The surface roughness was measured by Atomic Force Microscope (AFM). The roughness of the coated surfaces before and after the exposure was compared. For the two different flow conditions, i.e. impingement flow and stationary immersion, significant differences have been discovered from the EIS results and AFM results. We observed a more severe degradation in the epoxy coatings in impingement flow, and a rougher surface is formed for coating samples subjected to impingement flow.
Tribology and Electrochemical Corrosion Properties of TiC Thin Film Coatings Grown by RF Magnetron Sputtering
Authors: Olayinka Abegunde , Esther Akinlabi , Philip Oladijo 
Published: February 2021

Abstract
Titanium alloys have found application in many sectors and are regarded as one of the most valuable materials of the 21st century. Although titanium alloys have many promising properties, the tribo-corrosion properties still happen to be a limiting factor. In this research study, radio frequency (RF) magnetron sputtering was used to deposit refractory ceramic (TiC) thin films coatings on the surface of titanium alloys in order to enhance and improve the wear and corrosion resistance properties. Different combinations of the sputtering process parameters were used for the deposition process. The varied sputtering process parameters were RF Power, sputtering time, and temperature. The macroscratch, microscratch (adhesion test) and, corrosion properties of the coatings were investigated using the pin on-disk wear test, micro-scratch tribometer, and electrochemical potentiostat, respectively. The results show improvement in the wear and corrosion properties of the coated samples. The results also revealed the influence of the sputtering process parameters on the evolving wear and corrosion properties of the coated samples. Scanning electron microscope (SEM) was used to capture the wear scar and analyses the failure mode of the coatings.
Design and Experimental Evaluation of Mosquito-Inspired Needle Structure in Soft Materials
Authors: Gidde Sai Teja Reddy , Hutapea Parsaoran 
Published: February 2021

Abstract
Insects steer their stingers effortlessly to a specific target and release their venom in a certain path through the skin with minimal pain. These unique traits inspire the idea to develop bioinspired needles to reduce the insertion forces and to decrease the needle path deviation (deflection) for improved targeting accuracy. Our approach in this work focus on the design of mosquito-inspired needle and evaluation of the needle performance using vibration during tissue insertion. The mosquito-inspired needle design specifically consists of maxilla-shaped and labrum-tip design. The insertion force was measured using a force sensor, which was fixed at the needle end to measure the uniaxial force of needles. The applied vibration on the needle was measured along linear axis using piezoelectric actuator with a frequency of 150 Hz and an amplitude of 5μm. The needle was inserted at a constant speed by attaching the needle to a motorized linear stage. It was observed that the insertion forces of the proposed needle design with vibration showed a reduction by 27% compared to that of a conventional needle. This reduction in insertion force means that there is decrease in tissue gel phantom damage and it was also observed that needle bending has reduced due to reduction in bending stiffness of the tissue phantom. Furthermore, the needle insertion tests in real tissues (bovine kidney) considering the proposed needle geometry and vibration will be studied in future work to understand the bioinspired needle-tissue interactions.