bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive Spindle Balancing Using Magnetically Levitated Bearings
Authors: Barney Patrick , Lauffer James , Redmond James , Sullivan William , Petteys Rebecca 
Published: December 2021

Abstract
A technological break through for supporting rotating shafts is the active magnetic bearing (AMB). Active magnetic bearings offer some important advantages over conventional ball, roller or journal bearings such as reduced frictional drag, no physical contact in the bearing, no need for lubricants, compatibility with high vacuum and ultra-clean environments, and ability to control shaft position within the bearing. The disadvantages of the AMB system are the increased cost and complexity, reduced bearing stiffness and the need for a controller. Still, there are certain applications, such as high speed machining, biomedical devices, and gyroscopes, where the additional cost of an AMB system can be justified. The inherent actuator capabilities of the AMB offer the potential for active balancing of spindles and micro-shaping capabilities for machine tools. The work presented in this paper concentrates on an AMB test program that utilizes the actuator capability to dynamically balance a spindle. In this study, an unbalanced AMB spindle system was enhanced with an LMS (Least Mean Squares) algorithm combined with an existing PID (proportional, integral, differential) control. This enhanced controller significantly improved the concentricity of an intentionally unbalanced shaft. The study included dynamic system analysis, test validation, control design and simulation, as well as experimental implementation using a digital LMS controller.
Fuzzy Logic Semi-Active Vibration Control
Authors: Kim Sunghwan , Clark William W. 
Published: December 2021

Abstract
Fuzzy logic control is so-called artificial intelligence because control laws are designed by human decision, not by deterministic numerical calculations. This paper investigates the effectiveness of a fuzzy logic control method in vibration control with a semi-active MR fluid actuator. The system to be controlled is a simply supported beam to which is applied a persistent excitation. Numerical simulation and experimental tests are performed. Three semi-active control laws, one deterministic and two fuzzy-logic, were applied and compared on the basis of vibration control performance and energy consumption. These controllers are compared to the baseline fully-on control where the MR fluids are energized so that the actuator performs as a tuned passive damper. Simulation and experimental data were examined.
Three-Dimensional Microvascular Networks Fractal Structure: Potential for Tissue Characterization?
Authors: Craciunescu Oana , Das Shiva K. , Dewhirst Mark W. 
Published: December 2021

Abstract
It has been shown that the fractal dimension of 2D microvascular networks can discriminate between normal vs. tumor tissue (Gazit et al., 1995, 1997). We have determined the fractal characteristics of five 3D microvascular networks and conclude on the correlation between the computed fractal characteristics and the nature of the tissue of origin. The networks considered in the fractal analysis study were one rat tumor network (RT), one nude mouse tumor (NMT), one hamster skeletal muscle (HSM), one rat cremaster (RC), and one rat cerebral cortex (RCC). The networks were digitized in a 3D lattice starting from the known length, diameter and position of each segment in the network. The digitization process was performed such that the ratio between the initial occupation fraction of the vessels in the network and the occupation fraction after digitization is close to one. The resultant cubic lattices were analyzed using the concept of asymptotic fractals. The fractal dimension df, and the minimum path dimension dmin (that measures the tortuosity of the vessels) were determined for all the networks. Fractal behavior was noticed on length scales from 1–1.3 decades, dependent on the actual network size. The values obtained for the fractal dimension for the RT, NMT, RCC, RC and HSM microvascular networks are respectively, 2.6, 2.2, 2.29, 2.12 and 2.08. For the minimum dimension the values obtained are: 1.2, 1.1, 1.16, 1.1, and 1.1. By analyzing the available data, preliminary conclusions lead us to believe that a correlation between the fractal characteristics and tissue type might exist. Another important aspect is that the 3D RT microvascular network seems to have a percolation-like scaling which can be beneficial in monitoring the growing pattern using invasion percolation growth models. However, for general conclusions to be drawn, more networks have to be analyzed.
Osmotic Stress Initiates Intracellular Calcium Waves in Chondrocytes Through Extracellular Influx and the Inositol Phosphate Pathway
Authors: Erickson Geoffrey R. , Guilak Farshid 
Published: December 2021

Abstract
The biophysical environment of the chondrocytes plays an important role in the health, turnover, and homeostasis of articular cartilage. Under normal physiologic loading, chondrocytes are exposed to a complex and diverse array of biophysical signals, including mechanical and osmotic stresses, fluid flow, and fluid pressures [4]. Due to the charged and hydrated nature of the extracellular matrix, mechanical compression causes exudation of interstitial fluid in cartilage, which alters the osmotic environment of the chondrocytes. Confocal microscopy studies have shown that chondrocytes lose or gain volume in response to tissue compression [4] or changes in extracellular osmolarity [3]. The active process of volume recovery subsequent to osmotic shock has been shown to initiate intracellular signaling cascades [2], which may in turn alter cellular metabolism [6]. Although the mechanisms of intracellular signaling in response to osmotic stress are not fully understood, it has been hypothesized that intracellular transients and oscillations of calcium ion (Ca2+) are involved. The objective of this study was to examine the hypothesis that osmotic stress initiates a transient increase in the concentration of intracellular calcium ion ([Ca2+]i), and to determine the mechanisms of Ca2+ mobilization in isolated chondrocytes exposed to hypo- and hyper-osmotic stress.
Exploration of an Animal Model for Hypertrophic Scar Formation
Authors: Sojka Erik S. , Balis Ulysses , Sheridan Robert , Fowler Alex 
Published: December 2021

Abstract
In this paper we investigate the possibility of creating an animal model for hypertrophic scar formation by grafting healthy split thickness human skin onto the backs of athymic nude mice and then burning the grafts. We were able to show that the human tissue grafts do remain stable over extended periods and prove that the human dermis does not get infiltrated by mouse tissue. By burning the grafts for ten seconds at 70°C we found that we could not reproduce results previously reported; but by changing the burn parameters we were able to produce regions of dermal disorder that may indicate the formation of hypertrophic scar. These results represent the first replication of positive results using this animal model since it was first proposed 10 years ago.
The Question of Thermal Waves in Heterogeneous and Biological Materials
Authors: Tilahun Muluken , Scott Elaine P. , Vick Brian 
Published: December 2021

Abstract
There have been two recent experimental studies that have sparked a renewed interest in thermal wave behavior at the macro-scale level. Both reported thermal relaxation times of 10 seconds or higher. However, no further experimental evidence of this behavior has been reported. Due to the extreme significance of these findings, the objectives of this study were to try to reproduce these earlier studies and offer an explanation for the outcome. These two previous studies were repeated following the experimental protocol provided in the studies as closely as practically possible. First, studies on heterogeneous materials were repeated using sand, an ion exchanger, and NaHC03. A second set of experiments was conducted on bologna. In both cases, the temperature response to a specified boundary condition was recorded. The results from the first set of experiments suggested that the thermal relaxation times presented in the previous study were actually the thermal lag expected from applying Fourier’s Law taking into account the uncertainty of the temperature sensor. In the second set of experiments, unlike the distinct jumps in temperature found previously, no indication of wave behavior was found. Here the explanation for the previous results was more difficult to ascertain. Possible explanations include problems with either the data acquisition system or the temperature sensors used.
A Simplified Model for Encapsulated Phase Change Material
Authors: Hayes Linda J. , Spieker Michael A. , Wissler Eugene H. , Colvin David P. 
Published: December 2021

Abstract
One of the emerging technologies of this decade is macroencapsulated phase change materials (PCM), which is being developed to provide significantly enhanced thermal management for coolants, textile fibers, foams, composites and coatings with applications to avionics, spacesuits, machine coolants, apparel, packaging, and agriculture (Kaska and Chen, 1985, Colvin and Mulligan 1989). The encapsulated PCM is embedded or suspended in a conductive media. The characteristics of the capsules, the phase change material and the conductive media can be designed so as to provide enhanced thermal management in a wide variety of applications. The traditional way to model this system is to take a macroscopic view of the entire system, to use a volume averaged value for the release of latent heat from the PCM and to incorporate this term into the standard heat conduction equation. We propose a simplified model which has its origins in flow in porous media. The system is modeled with two components, the underlying conductive material and the phase change capsules. The amount of latent heat released from the PCM capsules is determined by the local temperature in the capsules, which can differ from the temperature in the conducting media. This model closely represents the physical systems which are being modeled Numerical results using this model are compared to experimental data from a garment layer which is constructed using macroencapsulated PCM capsules.
Melt Spun Fibers Containing Microencapsulated Phase Change Material
Authors: Bryant Yvonne G. 
Published: December 2021

Abstract
MicroPCMs are successfully being incorporated into solution-spun acrylic fibers, significantly increasing their thermal energy storage capability. However, melt-spun fiber production far exceeds that of acrylic fiber. Thus, the commercial potential of melt-spun fibers and resulting fabrics with enhanced thermal energy storage capabilities is enormous for the apparel and industrial insulation markets. However, at melt spinning temperatures, i.e., at temperatures &gt; 200° C, microencapsulated phase change materials (microPCMs) lose their core material, which corrupts the melt spinning process. Before these materials can successfully be incorporated into melt spun fibers, microcapsules &lt; 10 microns in size must be available with a more stable wall structure. This paper will discuss the results of NSF sponsored Phase I and II Small Business Innovation Research (SBIR) grants that investigated PCM microcapsules for high temperature application, and describe their inclusion into melt-spun fibers.
Three-Dimensional Analyses of Single Rivet-Row Lap Joints — Part I: Elastic Response
Authors: Iyer K. , Rubin C. A. , Hahn G. T. 
Published: December 2021

Abstract
Three-dimensional finite element analyses (FEA) of an elastic, single rivet-row, aluminum alloy lap joint are presented. The effects of rivet geometry (countersinking), rivet material and interfacial friction coefficient are examined. Interference and lateral clamping are not treated. Panels loaded in tension with vacant, tapered holes are also examined. Load transfer through the joint, the joint compliance, rivet-tilt, the local slips at rivet-panel and panel-panel interfaces, contact pressures and local stresses are evaluated. Relations between these features and the contact and bending driven stress concentration are clarified. The work shows that the stress concentration factor, rivet-panel slips, peak stresses, contact pressures and rivet deformation are all related, and increase with the severity of the countersink. Panel bending, rivet tilt and countersinking introduce large, out-of-plane stress gradients and shift the peak stresses to the interior surface of the countersunk panel. The results demonstrate the importance of out-of-plane distortions in accounting for the behavior of the riveted lap joints. Three opportunities are identified for improving lap joint performance without increasing the weight.
Two-State Conservation Integrals and Stress Singularities in Generic Wedges
Authors: Im Seyoung , Lee Yongwoo 
Published: December 2021

Abstract
The eigenvalues of Williams’ series expansion for generalized wedge problems, which include cracks, re-entrant corners, free edges, and cracks meeting with material interface, etc. are examined from the viewpoint of conservation laws like J-integral and M-integral. By use of the so-called two-state conservation laws or interaction energy, originally proposed by Eshelby and later treated by Chen and Shield, discussed is that the complementary pairs of eigenvalues exist in the J-integral sense and/or in the M-integral sense when these integrals are conserved. Similar results are shown to hold for the eigenvalues of three dimensional wedges.
Fatigue Behavior of Notched Resin Infusion Molded S2-Glass Twill Woven Composites
Authors: Kelkar Ajit D. , Chaphalkar Pramod 
Published: December 2021

Abstract
The present study provides the performance evaluation of 2 × 2 twill woven composite (S2-Glass and C-50 resin system) material for Integral Armor applications. The laminates were fabricated by using VARIM or RI (Vacuum Assisted Resin Infusion Molding). These components are expected to be under fatigue loading. Fatigue behavior of the unnotched and notched twill woven laminate is presented. Tension-Compression (R = −1) fatigue experiments were performed for both unnotched and notched panels. All the fatigue tests were performed at 1 Hz frequency. S-N diagram and stiffness degradation over the fatigue life of the specimen was obtained.
A Manufacturing Enterprise for Undergraduates, Phase I Report: Implementation
Authors: Carranti Frederick J. 
Published: December 2021

Abstract
An undergraduate course in the fundamentals of manufacturing processes has recently been redesigned to include a significant laboratory experience. Part of the motivation for this redesign was as a response to certain competency gaps in graduating engineers as identified by the Society of Manufacturing Engineers and by the industrial partners of the University. The nature of this laboratory experience prompts the students to participate in and manage an actual manufacturing enterprise. Many facets of a real company are explored including design, manufacturing, operations, accounting, purchasing, and marketing. The students are engaged in the design and production of a line of novelty items sold to the greater university community, and, in addition to product design, are also engaged in the design of all tooling and methods required for production. Due to the holistic nature of the experience, student enthusiasm and involvement are very high, and faculty endorsement has resulted in the course being named a required part of the curriculum for all future students in mechanical engineering. This paper describes the initial implementation of this course.
Mechatronics as a Capstone Design Course
Authors: Murray William R. , Garbini Joseph L. 
Published: December 2021

Abstract
Capstone design courses in engineering, which provide students the opportunity to tackle open-ended, real-world projects, are generally held in high regard as learning experiences. A relatively new and increasingly important component of engineering is the area of mechatronics. In this paper, we review the goals of capstone design courses and examine how well suited mechatronics projects are for use as projects in capstone design courses. Our experiences in using mechatronics projects in the senior-level capstone design course in the Department of Mechanical Engineering at the University of Washington are presented. From these experiences, we demonstrate that mechatronics projects are particulary well suited for use in capstone design.
Failure Analysis of a Shaft Belonging to a Ship Engine Speed Controller
Authors: Figueiredo Miguel V. , Oliveira Fernando M. , de Castro Paulo T. , Fernandes António A. 
Published: December 2021

Abstract
The fracture of a shaft belonging to the speed controller of a ship’s engine is presented. An over-speed situation occurred as a result of the fracture of this shaft, which led to severe damage to the engine.
The failure examination concentrated first on the study of the available evidence, which included the analysis of the shaft’s material and fracture surface.
The shaft’s material was studied as concerns chemical composition, mechanical properties and micrographic structure. The fracture surface was studied using scanning electron microscopy. Several different destructive laboratory tests were conducted on the material, in order to obtain fracture surfaces which could be used for comparison purposes, and thus help to identify the cause of the fracture.
The next step of the failure analysis consisted of a stress analysis of the shaft under service conditions.
A probable scenario for the failure was proposed, which helped the interested parties to reach an agreement concerning responsibilities for the failure. It was found that the shaft material presented low notch toughness. The stress levels at the time of the accident imply that it is unlikely that the fracture was due to fatigue. The probable cause of the failure was sudden blockage of the shaft.
Prediction of Looper Response in the Hot Strip Finishing Mill
Authors: Hsu Yuan-Liang , Cheng Chi-Cheng , Wen San-Lan 
Published: December 2021

Abstract
The looper system, located midway between adjacent stands, is a mechanical levitation device commonly applied on modern hot strip mills. In order to fully understand factors affecting the looper’s behavior and predict its motion during rolling processes, a comprehensively mathematical simulation model of the looper control system for a hot strip tandem mill is developed. The simulator includes three system modules: the looper regulator module, the looper dynamics module, and the mass flow module. Simulation results demonstrate good compatibility with position measurement of real rolling processes. Looper responses under circumstances of different original strip lengths and a varying roller speed are specifically examined. Based on this looper simulator, valuable information can be easily obtained for possible improvements on rolling processes in the future.
Manufacturing Process Optimization With Artificial Neural Networks
Authors: Sihn Wilfried , Schmidt Thomas 
Published: December 2021

Abstract
Today’s manufacturing methods are caught between the growing need for quality, high process safety, minimal manufacturing costs, and short manufacturing times. In order to meet these demands, process setting parameters have to be selected carefully with close attention being paid to quality needs. For such optimization it is necessary to represent the processes in a model. Due to the enormous complexity of many processes and the high number of influencing parameters, however, conventional approaches to modeling and optimization are no longer sufficient. This article shows how the application of neural networks for process modeling can simplify these highly complex interdependences so that both process and quality parameters can be assessed before or during processing. By connecting them with corresponding cost models, it is possible to optimize processes with the help of evolutionary algorithms. Using different manufacturing processes as examples, the authors demonstrate how process modeling can be optimized using neural networks and evolutionary algorithms.
A 3-D Closed-Form Cutting Force Model for End Milling With Application to Sculptured Surface Milling
Authors: Lee T. S. , Farahati R. , Lin Y. J. 
Published: December 2021

Abstract
A comprehensive, 3D mathematical model of desired/optimal cutting force for end milling of free-form surfaces is proposed in this paper. The closed-form predictive model is developed based on a perceptive cutting approach resulting in a cutting force model having a comprehensive set of essential cutting parameters. In particular, the normal rake angle usually missing in most existing models of the same sort is included in the developed model. The model also enables quantitative analyses of the effect of any parameters on the cutting performance of the tool, providing a guideline to improving the tool performance. Since the axial depth of cut varies with time when milling sculptured surface parts, an innovative axial depth of cut estimation scheme is proposed for the generation of 3-D cutting forces. This estimation scheme improves the practicality of most existing predictive cutting force model for milling in which the major attention has been focused on planar milling surface generation. In addition, the proposed model takes the rake surface on the flute of mills as an osculating plane to yield 3-D cutting force expressions with only two steps. This approach greatly reduces the time-consuming mathematical work normally required for obtaining the cutting force expressions. A series of milling simulations for machining free-form parts under scenario cutting conditions have been performed to verify the effectiveness of the proposed cutting force model. The simulation results demonstrate accurate estimating capability of the proposed method for the axial depth of cut estimation. The cutting force responses from the simulation exhibit the same trends as what can be obtained using the empirical mechanic’s model referenced in the literature. Finally, through the simulation results it is also learned that designing a tool with a combination of different helix angles having cutting force signatures similar to that of the single helix angle counterparts is particularly advantageous.
Application of an Internally Consistent Material Model to Determine the Effect of Tool Edge Geometry in Orthogonal Machining
Authors: Schimmel Roy J. , Endres William J. , Stevenson Robin 
Published: December 2021

Abstract
It is well known that the edge geometry of a cutting tool affects the forces measured in metal cutting. Two experimental methods have been suggested in the past to extract the ploughing (non-cutting) component from the (total) measured force; 1) the extrapolation approach and 2) the dwell force technique. This study reports the behavior of zinc during orthogonal machining, using tools of controlled edge radius. It was determined that application of neither the extrapolation nor dwell approaches yielded a material response that is consistent with the known behavior of zinc. Further analysis shows that the edge geometry modifies the shear zone of the material and thereby modifies the forces. When analyzed this way, the measured force data yield the expected material response without requiring recourse to an additional ploughing component.