bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D Finite Element Assisted Numerical Simulation of Orbital Drilling Process of Ti6Al4V
Authors: Pervaiz Salman , Daneji Ali , Kannan Sathish 
Published: January 2020

Abstract
Drilling is one of most executed manufacturing operations to assist the assembling of different engineering components. In orbital drilling process, a milling tool is rotating along its own axis in combination with the spiral rotational movement. The rotation of tool about its own axis is with high rotational speed, but the spiral movement of tool is at low rotational speed. These rotational movements generate a hollow geometry when moved in combination. Orbital drilling process is emerging as a viable drilling process when burr formation has to be reduced from the metallic workpiece. It is gaining more popularity in the aerospace industry due to its ability to machine holes in difficult to cut alloys, composites and composite stacks. Major advantages of orbital drilling are linked with efficient chip evacuation, reduction in heat build-up and low thrust forces due to its intermittent cutting nature.
The cutting forces generated during the process can be taken as a significant output parameter that play a vital role towards the overall performance of the cutting process. Controlling the cutting forces under threshold value can improve the overall machining efficiency by limiting associated deflections, tool wear and energy consumption. The current paper aims to study the orbital drilling process using finite element (FE) assisted numerical methodology. The study will utilize different orbital drilling parameters such as spindle speed, orbit speed and axial feed rate, and explore their influence on the over all machining process.
Spatial Variations in Achilles Tendon Shear Wave Speed Using a Cost-Effective Method of Accelerometers
Authors: Salman Muhammad , Ge Conghui , Morris Clint 
Published: January 2020

Abstract
Currently there are no cost-effective ways to quantitatively measure the in-vivo mechanical properties of the Achilles tendon. Stiffness can be used as a measure of tone and mechanical integrity of both muscles and tendons. Stiffness of the Achilles tendon (AT) can be quantified by the speed of shear wave propagation. The speed of propagation can then be used to find the instantaneous shear modulus. Currently there are other methods such as Ultrasound (US) imaging and Magnetic Resonance Imaging (MRI) which are used clinically to determine the variations in stiffness of the AT. However, these methods require complex signal processing and experienced technicians. Moreover, US imaging technique is limited in measuring high shear wave speed values which are greater than 17 m/s. In this research, one-dimensional accelerometers were used to measure acceleration through the AT. Then a cross-correlation signal processing technique was used to convert acceleration to the velocity of shear wave propagation across the AT. This method could potentially evaluate the mechanical properties of both normal and damaged tendons. This process has proven to be a cost-effective and simple way to assess the stiffness of the AT. The modulus of elasticity (E) was found using the following relation: E = 3ρV2.
Investigating Density Functional Theory’s Effectiveness in Studying Metal-Organic Frameworks Structures
Authors: Roberts Kendric , Han Yen-Lin 
Published: January 2020

Abstract
In combatting human induced climate change, carbon capture provides the potential to more slowly ease away from the dependence on hydrocarbon fuel sources, while mitigating the amount of CO2 released into the atmosphere. One promising material to use is metal-organic frameworks (MOF’s). MOF’s offer an immense variety in potential exceptionally porous structures, a property important in separation. As a result of practical experimental measurements being expensive and time consuming, interest in accomplishing the same goal through modeling has also increased. Using density functional theory to optimize the approximate experimentally measured atomic geometries has been shown to have sufficient accuracy. A previous study by Nazarian et al. was performed to optimize structures on the CoRE MOF Database using a supercomputer. The purpose of this study was to attempt to replicate their work done with a single MOF using computational resources more commonly available. Furthermore, as time tends to be the limiting factor in conducting these studies, the use of a smearing function was adjusted for two optimizations to see if any considerable improvement on the efficiency of the optimizations could be made. Our results show both optimizations improved the bond length accuracy relative to the raw data compared with the optimization from Nazarian, et al. The optimization with a more present smearing effect was able to converge the electron field in roughly half the time, while still showing nearly the same results, except for slightly more variability in the bond lengths involving transition metals. Unfortunately, the improvement in bond length, did not correspond in consistent improvement of the larger cell defining metrics. This shows that either a different energy minimum was found or the relationship between the larger cell parameters, with the more local parameters such as bond length is too complex for the method to effectively solve.
The Potential of Solar Cooling Using a Medium Concentration Photovoltaic-Thermal System
Authors: Abdel-Mesih Bahy 
Published: January 2020

Abstract
Using solar energy for space cooling is a very interesting concept that relies on several facts. First, both the solar gains and cooling loads or demand coincide with each other. The high insolation levels in summer increase indoor temperatures and accordingly increase the necessity for cooling to fulfill the comfort requirements of occupants. Second, in summer, the electric peak loads occur due to excess usage of electrically-driven air-conditioning systems. Third, there is a surplus of solar gains in solar systems designed for heating applications during the summer season. In this work, the author investigates the usage of the heat produced by a concentrated photovoltaic-thermal (CPVT) system for running an absorption chiller for cooling applications. The CPVT generator is a 22-suns linear Fresnel reflecting system. Water pipes run beneath the PV cells to cool them down, improving their efficiency, and thus simultaneously producing hot water. Different areas of the concentrator and configurations of storage tanks are looked at. TRNSYS simulation platform is used in this study. Results show great potential for a system that produces electricity, hot domestic water, and cooling effect.
Digital Twin in a Manufacturing Integrated System: Siemens TIA and PLM Case Study
Authors: Guerra-Zubiaga David A. , Bondar Alex , Escobedo Gilberto , Schumacher Arthur 
Published: January 2020

Abstract
The new industrial revolution called Industry 4.0 embraces diverse Digital Manufacturing Tools (DMT). Trying to improve Product Life-cycle Management (PLM), some companies are trying to implement DMT to create Digital Twins (DT). New Product Introduction (NPI) demands large effort in digitalization and virtual simulation through the PLM process. Sometimes a new product could be only the development of a single component and/or an entire manufacturing process including complex instruments and controls. In this direction, it is important to accelerate Manufacturing Integrated Systems (MIS) by improving the automation not only in the NPI, but also in the PLM. This paper integrates Siemens PLM software as DMT called Tecnomatix Process Simulate (TPS), Totally Integrated Automation (TIA) and PLCSIM advanced. The scope in the NPI is showing how a Digital Twin could help the MIS. The aim of this paper is to evaluate the interconnectivity of a small physical prototype with its virtually simulated clone to support the virtual commissioning for a NPI.
Two Methods for the Constitutive Modeling of TiB2/7050 Al Composites
Authors: Lin Kunyang , Wang Wenhu , Jiang Ruisong , Liu Xiaofen , Zhu Xiaoxiang , Zhang Zhanfei 
Published: January 2020

Abstract
In this paper, the Johnson-Cook constitutive model of in situ TiB2/7050 Al metal matrix composites determined by two different methods are compared. The commonly used quasi-static and dynamic compressive experiments are firstly conducted under the strain rate range of 10−3∼5000s−1 and temperature range of 20∼200 °C. The orthogonal cutting experiments are also used to calculate the JC model. The description ability of two models are evaluated by two statistical parameters: correlation coefficient and average absolute error. The results show that the JC model determined by the compression experiments performs better to describe the stress-strain behavior of in situ TiB2/7050 Al composites. Although the JC model from orthogonal cutting experiments can be used to simulate the cutting process, it cannot describe the flow stress behavior exactly during material deformation processes. For an accurate constitutive model of a material, the basic tensile or compression test is deemed necessary.
Synthesis and Deposition of Rutile TiO2 for Dye-Sensitized Solar Cell Applications
Authors: Teferi Blen , Schnupf Udo , Manseki Kazuhiro , Sugiura Takashi , Vafaei Saeid 
Published: January 2020

Abstract
The purpose of this research was to produce semiconductor Rutile TiO2 films using a new deposition method on F-doped SnO2 (FTO) glasses i.e. nanofluid boiling method, using TiO2 nanoparticles. A low-temperature synthesis without using conventional hydrothermal methods was established to obtain the Rutile TiO2 nanoparticles with different size and shape under different temperatures. The crystalline TiO2 was separated from the reaction liquid by centrifugation and dried under ambient condition. The current boiling deposition of the TiO2 nanofluid was found to form porous semiconductor TiO2 nanoparticle films without cracks in the deposited TiO2 film. The obtained TiO2 films will be utilized as TiO2 photoanodes in dye-sensitized solar cells.
Anisotropic Deformation Behavior of Porous Polymeric Membranes Under Uni-Axial and Bi-Axial Loadings
Authors: Emori Kanako , Yonezu Akio , Nagakura Takumi , Miura Tatsuma 
Published: January 2020

Abstract
This study systematically investigates the uniaxial and biaxial tensile deformation behavior of polytetrafluoroethylene (PTFE) membranes which are used for water purification. The present PTFE membrane has micron size pores with open cell structure, and the pore is anisotropic shape. During the uniaxial tensile test, the membranes undergo elastic deformation and plastic deformation with strain rate sensitivity (i.e. time-dependent deformation behavior). In addition, it strongly demonstrates anisotropic deformation, i.e. deformation behavior is different along longitudinal direction and transverse ones. To clarify the microscopic deformation mechanism, in-situ SEM observation is carried out during tensile loading. It is found that the anisotropic deformation behavior appears due to the inherent pore structure. Next, to investigate deformation behavior under biaxial loading condition, small punch test using a spherical indenter is carried out. The membrane undergoes elastic and plastic deformations. Finally, crack nucleates around the indenter contact and indenter completely penetrates through the membrane. It is also found that the membrane demonstrates anisotropic out-of-plane deformation behavior. To clarify these mechanisms, FEM computation is carried out, such that experimental results of force-displacement curve and out-of-plane deformation behavior are compared with the computational ones. The present FEM model enables the prediction of the membrane’s deformation behavior under biaxial loading.
Study on Turning of Non-Axisymmetric Three-Dimensional Curved Surfaces
Authors: Nakagawa Kensuke , Mori Taichi , Morimoto Yoshitaka , Hayashi Akio , Kaneko Yoshiyuki , Suzuki Naohiko , Hirono Ryo 
Published: January 2020

Abstract
Conventional machining of complex parts having three-dimensional curved surfaces is done by two processes using a five-axis machining center and a grinding machine. Although these tools make it possible to machine a product with complicated profiles, the tool path is complex and the process is time consuming. Also, because the amount of movement accompanying the control of the tool position increases, the productivity decreases. Therefore, we developed a CNC lathe for high-speed and high-efficiency machining in a previous study. The NC positioning table on which the tool is mounted is synchronized with the rotation angle of the main spindle; thus, the developed CNC lathe can form a three-dimensional curved surface on a workpiece. However, the previous study did not evaluate the surface profile of a product created with the developed CNC lathe.
In this study, for the purpose of improving the contour accuracy of the machined workpiece, we propose a method for on-machine measurement and compensated machine tool position using the measurement result. The proposed on-machine measurement method is a non-contact method that employs a line laser displacement sensor. In the proposed method, the workpiece attached to the spindle of the CNC lathe is moved to a sensor reference position and measured. The measurement position is recorded in the NC machining program; thus, it is possible to adjust the tool position during machining to reduce the machining error by feeding the measurement results back to the machining program. Because machining is started in a state offset from the machining origin, the compensated machining can deal with both overcutting and undercutting of the workpiece. Testing of the proposed compensated method confirmed improvement in the desired profile accuracy.
Inverse Optimization of Design Parameters in a Hybrid Solar Pond System With External Heat Addition
Authors: Kumar Abhishek , Das Ranjan 
Published: January 2020

Abstract
External heat supply to solar ponds from various types of solar collectors is a feasible alternative that significantly enhances its performance. In this work, various design parameters in a hybrid solar pond with external heat addition from Evacuated Tube Solar Collector (ETSC) are evaluated using an inverse approach. A forward model based on heat balance equations is solved for various zones of the solar pond to predict temperatures attained by its storage zone under a given climatic condition. Bryant and Colbeck’s relation is used to account for the diminution of the solar radiation as it travels from upper layers of the solar pond to its bottom layers. The relevant differential equations are solved using a Runge-Kutta fourth order scheme. The component of heat addition from ETSC is added to the forward model in the storage zone’s equation. Heat added from ETSC is considered proportional to the fraction of the aperture area to the pond’s base area, the thermal efficiency of ETSC and global solar radiation incident on ETSC. Both the forward model of the solar pond and combined solar pond and ETSC model were validated with previous experimental and numerical studies available in the literature for El Paso, USA, and Melbourne, Australia. An inverse model based on genetic algorithm is proposed for evaluating the set of geometrical parameters of ETSC and solar pond in order to derive a required performance from the combined solar pond-ETSC system.
Influence of Input Image Configurations on Output of a Convolutional Neural Network to Detect Cerebral Aneurysms
Authors: Watanabe Kazuhiro , Anzai Hitomi , Juchler Norman , Hirsch Sven , Bijlenga Philippe , Ohta Makoto 
Published: January 2020

Abstract
Rupture of cerebral aneurysms is the main cause of subarachnoid hemorrhage, which can have devastating effects on quality of life. The identification and assessment of unruptured aneurysms from medical images is therefore of significant clinical relevance.
In recent years, the availability of clinical imaging data has rapidly increased, which calls for computer assisted detection (CAD) systems. Previous studies have shown that CAD systems based on convolutional neural networks (CNN) can help to detect cerebral aneurysms from magnetic resonance angiographies (MRAs). However, these CAD systems require large datasets of annotated medical images. Thus, more efficient tools for processing and categorizing medical imaging data are required.
Previous studies of CNN-based classification for medical images used various patch configurations of input data. These studies showed that classification accuracy was affected by the patch size or image representation. Thus, we hypothesize that the accuracy of CADs to detect cerebral aneurysms can be improved by adjusting the configuration of the input patches.
In the present study, we performed CNN-based medical imaging classification for varying input data configurations to examine the relationship between classification accuracy and data configuration.
3D Assembly Model Matching Based on Motion Features and Shape Distribution
Authors: Baoning Ji , Yuan Li , Jie Zhang , Jianfeng Yu 
Published: January 2020

Abstract
Assembly retrieval is a significant technology to reuse the abundant design knowledge embedded in the products. However, the existing assembly retrieval methods are still lacking and the research on this topic is needed. It is found that the motion features of the internal mechanism in the assembly model are closely related to its mechanical function, which is significant for mechanism motion design, assembly simulation, etc. So we propose an approach for assembly matching by motion and shape features. First, assembly model are decomposed into separate kinematic components according to analyzing its motion structure. Then, we take geometric information of kinematic component as a vertex, and kinematic pair between components is taken as an edge to construct graph-based assembly descriptor, which contains motion features of the assembly. Afterwards, Ullmann algorithm is introduced to match the input descriptor with the assemblies in the library, and the maximum subgraph of them is solved so as to estimate the similarity. In case study, some experiments have been carried out, and the results have shown the feasibility of the method proposed in this paper and demonstrated the practical value in engineering.
Real-Time Assembly Recognition Based on the Similarity Between Spatial Increment and Part Model
Authors: Pang Jiazhen , Li Yuan , Zhang Jie , Yu Jianfeng 
Published: January 2020

Abstract
Manual work is a weak link within the intelligent manufacturing, however, it plays an important role in the highly customized and multi-variety assembling. Assisted by intelligent assembling technology such as augmented reality, a manual worker can integrate into the cyber-physics system to improve efficiency and reduce errors, which is of great engineering significance in the assembling field of industry 4.0. Assembly recognition is the initial part of progress analysis and it has predictable changing progress stages which can be matched with the digital model for recognition constraints. Therefore, based on the similarity between spatial increment information and part model, a real-time assembly recognition method is proposed in this paper. Firstly, the depth images from the multi-camera system were used to capture the assembling scene. Then, compared with the previous assembling scene, the spatial incremental information was used to quantitatively represent the assembled part. The spatial increment information and digital model are described with distance distribution. Finally, based on Earth mover’s distance algorithm, the matching between the spatial increment information and the part model indicates the part which had been assembled to realize the real-time assembly recognition. In the case study, an assembling process for 3D printing assembly which corresponded with the digital model was used to approve the feasibility of the real-time assembly recognition method.
Coordinated Motion Planning of Legged Mobile Manipulator for Tracking the Given End-Effector’s Trajectory
Authors: Bhavanibhatla Kondalarao , Suresh-Fazeela Sulthan , Pratihar Dilip Kumar 
Published: January 2020

Abstract
In this paper, a novel algorithm is presented to achieve the coordinated motion planning of a Legged Mobile Manipulator (LMM) for tracking the given end-effector’s trajectory. LMM robotic system can be obtained by mounting a manipulator on the top of a multi-legged platform for achieving the capabilities of both manipulation and mobility. To exploit the advantages of these capabilities, the manipulator should be able to accomplish the task, while the hexapod platform moves simultaneously. In the presented approach, the whole-body motion planning is achieved in two steps. In the first step, the robotic system is assumed to be a mobile manipulator, in which the manipulator has two additional translational degrees of freedom at the base. The redundancy of this robotic system is solved by treating it as an optimization problem. Then, in the second step, the omnidirectional motion of the legged platform is achieved with a combination of straight forward and crab motions. The proposed algorithm is tested through a numerical simulation in MATLAB and then, validated on a virtual model of the robot using multibody dynamic simulation software, MSC ADAMS. Multiple trajectories of the end-effector have been tested and the results show that the proposed algorithm accomplishes the given task successfully by providing a singularity-free whole-body motion.
Elimination of Sommerfeld Effect in Non-Ideal Systems Using Dry Friction
Authors: Chakraborty Pratyaya , Chakraborty Goutam , Bhattacharyya Ranjan 
Published: January 2020

Abstract
Most of the power sources of mechanical systems can only deliver limited amount of power. Due to this insufficiency of power, often the system fails to achieve a smooth passage through resonance. For example, a non-ideal DC motor driven vibrating system with viscous damping often gets stuck near resonance speed of the system as a large amount of supplied power is utilized to oscillate the system which causes a scarcity of power for the motor speed to go past the resonance condition. However, most of the available power can be used to rotate the motor shaft if somehow the oscillating motion is arrested or minimized. In this paper, a study of a non-ideal DC motor driven mechanical system with dry friction is presented. The response of the system under stick phase, as given by the Karnopp model of friction is found and subsequently, a nonslip operating condition is obtained analytically. With the help of numerical results, the obtained nonslip condition is verified for different voltage inputs. A smooth variation of rotational speed of the motor shaft is numerically achieved without being affected by the Sommerfeld Effect.
Influence of Timestep and Mesh Sizes on Numerical Simulations of Boundary Value Problem Model of Electrostatically Actuated MEMS Resonators
Authors: Beatriz Julio , Caruntu Dumitru I. 
Published: January 2020

Abstract
This paper deals with the effects of mesh size and time step on the numerical simulations using bvp4c, a Matlab Boundary Value Problem solver, on the time response of electrostatically actuated MEMS resonators. These results are compared to the reduced order model as well as the method of multiple scales to test how accurate these results are at lower amplitudes. The refinement of mesh size leads to more accurate results to a certain extent, as it eventually reaches a convergence. It should be said that the larger the mesh size, the longer the calculations take. A similar result occurs with timestep size. The smaller the timestep the more accurate the results. However, the CPU time increases significantly. However, beyond a certain timestep, any smaller time step would not yield any noticeable differences. Thus it can be said convergence has been reached.