bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechatronics: A Thread in the Mechanical Engineering Undergraduate Curriculum
Authors: Murray William R. , Garbini Joseph L. 
Published: January 2022

Abstract
Mechatronics is the synergistic combination of mechanical, electrical, and computer technologies in the design of complex products and processes. Recent rapid growth of mechatronics as an area of engineering has given rise to a significant demand for mechatronics engineers. At the university level, engineering programs have emerged that help meet this need by producing engineering graduates who are capable, well-rounded mechatronics designers.
One such program is the multi-course guided curriculum in mechatronics that is available to students in their senior year in the Mechanical Engineering Department at the University of Washington. Described in this paper are that mechatronics program as a whole, the curriculum into which it fits, the individual constituent courses, and our observations after offering this program for two years.
Discretizors and Interpolators for Five-Axis CNC Machines
Authors: Sarma Radha , Rao Aarthi 
Published: January 2022

Abstract
Discretization and interpolation of curves are two frequently adopted practices when machining complex curves using computer numerically controlled (CNC) machines. Both practices stem from the need to sample curves at discrete time intervals corresponding to the sampling period of the CNC machine. This paper proposes new techniques for discretization and interpolation that account for the change of tool orientations in five-axis machining. Firstly, the method for discretization proposed in this paper is based on sampling the curves such that specified contour, feedrate, and orientation errors are not exceeded. Secondly, the interpolator proposed in this paper will be able to avoid excessive angular velocities arising from sampling the curves based on the feedrate alone.
Stability and Control of Linear Motor Feed Drives for the End Milling Process
Authors: McNab Robert J. , Tsao Tsu-Chin 
Published: January 2022

Abstract
Linear motor direct drive actuators are implemented as feed drives for the end milling machining process. An H∞ optimal feedback controller is designed and analyzed for performance, stability, and robust stability. A simplified cutting process model is presented for use in system stability analysis. Because of uncertainty in the cutting process model and the multivariable nature of the system when cutting is taking place, a μ analysis approach is taken to establish stability boundaries for the machine parameters. Experimental results verifying the cutting process model, examining the feedback controller performance, and verifying the accuracy of the robust stability analysis are presented.
Open Architecture Based Framework in Integrated Precision Machining System
Authors: Lee Yoon , Dornfeld David A. , Wright Paul K. 
Published: January 2022

Abstract
This paper introduces a current effort in the application of an open architecture (OA) control system in precision machining at Berkeley’s Laboratory for Manufacturing Automation (LMA). In the first part of this paper, issues in precision machining relative to the application of OA control systems and a higher level framework for conceptualizing the integration of a precision manufacturing process using an existing OA manufacturing scheme is proposed. In the second part, the first level of implementation of an open architecture controller system on a single point diamond turning machine is presented.
Developments in Nonlinear Control System Synthesis Research
Authors: Garg Devendra P. 
Published: January 2022

Abstract
The control of nonlinear systems presents a particularly challenging problem for engineers since the dynamics of such systems is inherently complex. The principle of superposition does not hold, and the dynamic response is generally initial condition specific. In 1978, the ASME’s Dynamic Systems and Control Division had published a monograph entitled Nonlinear System Analysis and Synthesis: Vol. 1 - Fundamental Principles (Edited by J. Karl Hedrick and Henry M. Paynter), which consisted of five chapters. The titles and authors of the first four chapters, respectively, were Some Fundamental Principles of Nonlinear Systems by Andrew U. Meyer; Stability of Nonlinear Systems by Kumapati S. Narendra; Nonlinear System Response: Classical Techniques for Unforced Response by Henry M. Paynter; and Nonlinear System Response: Quasi-Linearization Methods by J. Karl Hedrick. The author of the present paper has had a long standing interest in the controller synthesis research [see, for example, References 01–08]. He was also the contributor of the fifth and final chapter entitled Nonlinear Controller Synthesis, in that monograph. A number of innovative approaches have been developed for controller synthesis since the publication of the ASME monograph, particularly under the sponsorship of National Science Foundation’s Dynamic Systems and Control Program. This paper traces some of the recent developments in the area of nonlinear control system synthesis. These developments are illustrated with a few specific examples of techniques advanced during the course of research sponsored by NSF.
A 2D Biomechanical Model of the Human Tongue
Authors: Payan Yohan 
Published: January 2022

Abstract
This study aims to evaluate the impact of anatomical, morphological and biomechanical properties of one of the main articulator, namely the tongue, onto the kinematic properties of speech movements. For this, a 2D biomechanical Finite Element model of the tongue was developed. It integrates four extrinsic muscles and three intrinsic ones. This model is controled according to the Equilibrium Point Hypothesis, proposed by Feldman (1966, 1986). The deformations of the model are computed, in order to simulate Vowel-to-Vowel transitions. The articulatory patterns synthesized with this model are then compared to data collected on a male native speaker of French. Emphasis is put on the potential influence of biomechanical tongue properties on to measurable kinematic features.
Improving the Performance of a Geophone Through Capacitive Position Sensing and Feedback
Authors: Barzilai Aaron , VanZandt Tom , Kenny Tom 
Published: January 2022

Abstract
This paper reports on the improved performance of a geo-phone obtained by measuring the displacement of its proof mass capacitively rather than inductively and operating the sensor as a closed loop system. A measurement of the displacement of the proof mass rather than the velocity measurement made with a conventional geophone provides better low frequency performance. As a result, a geophone can be considered for use in a broader array of applications. A capacitive geophone can operate in either an open loop or closed loop mode. This paper describes a closed loop geophone system with a frequency response similar to the state of the art Streckeisen seismometers.
On-Line Identification of Model Parameters for a Liquid Fuel Film Present in the Induction System of a Gasoline Engine
Authors: He Chuan , Chalhoub Nabil G. 
Published: January 2022

Abstract
Optimal efficiency of the three-way catalytic converter can only be achieved if the air-to-fuel ratio (AFR) is kept at the stoichiometric level. However, large excursions of the AFR have been observed during transient operations of port injection engines. These excursions are induced by the intake manifold filling, fueling strategy, wall-wetting and sensor dynamics. Therefore, to have tight control over the AFR, both air and fuel flows in the induction system must be accurately known.
This work focuses on the fuel transport characteristics within the induction system. It considers a first order fuel film model whose parameters are constantly updated by an on-line system identification scheme. A nonlinear engine model used herein as a test bed to assess the performance of the identification algorithm. The digital simulation results demonstrate the capability of the proposed approach in enhancing the accuracy of the fuel puddle model.
Learning From Operating Experience at the Department of Energy
Authors: Rollow T. A. , Marchese A. R. , Day R. E. 
Published: January 2022

Abstract
The Office of Environment Safety and Health (EH) within the Department of Energy (DOE) has a program for the analysis of facility operations. Tools used in this study include measures of safety, called “performance indicators,” which reports occurrences, and the identification of underlying causes of both desirable and undesirable events, referred to as “lessons learned.” The overall goal of the study is the development and continual improvement of a comprehensive integrated safety management system.
Safety Factors Relating to Monitored Compactor Operating Parameters
Authors: Etherton J. R. , Moore P. H. , Harris J. R. , Zeng S. 
Published: January 2022

Abstract
Recent NIOSH fatality investigations have shown that workers risk amputation and crush injury while attempting to clear jammed material from the loading chambers and feed chutes of operating baling and compacting equipment. A recent NIOSH study suggests that signals generated by strain gage transducers could be used to warn of impending jams. Strain gages placed at locations on the machine’s frame experiencing large deformations preceding jams would be used to trigger a visual or audible alarm. A system safety analysis using FaultrEASE software was conducted to describe the sources of variation in operating conditions that could confound the transducer response of the proposed safety device. Monitoring will require adequate signal conditioning to adjust for the effects of temperature differentials, vibration, electromagnetic interference, and other factors present in the indoor and outdoor operating environments typical for these machines.
An experimental study was also conducted. Readings were collected from strain gages bonded to an integral horizontal compactor container. Readings were taken once a day as the compactor was normally being filled. Independent variables included: gage site; gage length; relative amount of compactor fill; and gage orientation. The dependent variable was strain gage voltage response under normal compactor cycling. The strains that were indicated were clearly biaxial and dynamic. Varying gage length and location produced significantly different responses. Substantial changes in gage response were recorded as material volume increased in the container. Mechanical blocking of the platen and proper lockout/tagout should remain the primary control of hazardous energy to prevent baling-equipment-related amputation and crushing injury.
Passenger Rail Vehicle Dynamic Performance: Tests and Analysis Correlations
Authors: Samavedam Gopal , Gomes John , Warren Peter , Tsai Thomas 
Published: January 2022

Abstract
Passenger rail vehicles have to operate on a variety of track geometries: tangent, curved and spirals connecting tangents to constant radius curves. The maximum levels of vertical and lateral misalignment and the maximum amount of crosslevel variation that can be safely negotiated are important in safety evaluations.
The overall objective of this paper is to show that experimental characterization with detailed simulation can accurately predict the dynamic response of passenger rail vehicles in safe and unsafe operational regimes. The validation of the simulation tool is a part of the safety assessment methodology. Computer simulations of the vehicle dynamic response were formulated to incorporate the track flexibility.
Dominance Zone for J-A2 Characterization of Crack-Tip Fields and Size Requirements for Fracture Testing
Authors: Chao Yuh J. , Zhu X. K. 
Published: January 2022

Abstract
Using the J2 flow theory of plasticity and within the small-strain framework, full-field finite element solutions are obtained for both deep and shallow crack geometries of single edge notch bar under pure bending [SEN(B)] and central cracked panel in uniform tension [CC(T)]. These crack-tip stresses are compared with those in the HRR singularity fields and the J-A2 three-term asymptotic solutions at the same level of applied J. The comparison indicates that the size of the region dominated by the J-A2 three-term solution is much larger than that of the HRR field around the crack tip. Except for deep crack SEN(B) in low hardening material (e.g. n = 10 ) under fully plastic conditions, the numerical results near the crack tip in both SEN(B) and CC(T) match very well with the J-A2 three-term solutions in the area of interest 1 &lt; r / (J / σ0) &lt; 5 from well-contained to large scale plasticity. The implications of these results on the minimal specimen size requirements essential to a two-parameter fracture testing based on the J-A2 three-term asymptotic solution are then discussed.
Discrepancies Between High Temperature Fatigue Life Prediction Models
Authors: Moftakhar Abbas A. 
Published: January 2022

Abstract
One feature of creep fatigue data is the large amount of scatter present, even for test specimens taken from the same heat of material and tested under nominally identical conditions. This has led to considerable discrepancies between methods proposed during the last 40 years for fatigue life prediction of high temperature components. Presently, there is no general agreement on optimum approaches.
The inadequacy of the Manson-Coffin law for high temperature use is discussed. The frequency modified fatigue life model and the strain range partitioning method, two popular extensions of the Manson-Coffin law for high temperature use, are studied. Major differences in terms of mechanistic interpretations and mathematical formulations between these two models are investigated. Also, difficulties in the realistic application of these methods are studied and some simplified solutions are proposed.
The time-dependent damage rule of the ASME Boilerand Pressure Vessel Code is studied for its application to notched components and issues such as creep rupture under compressive stress, creep rupture time of notched components, and cyclic creep rupture curves vs. static creep rupture curves are discussed. Difficulties in the calculation of the time fraction term of this method are investigated for notched components and a simplified solution is proposed.
Theory of Box-Type Sandwich Shells With Dissimilar Facings Subjected to Thermomechanical Loads
Authors: Birman Victor , Simitses George J. 
Published: January 2022

Abstract
The present paper outlines a theory of sandwich box-type composite shells designed to withstand a combination of thermal loading, internal pressure, torsional and axial loads. A cross section of the shell represents a rectangular box with curved cylindrical sections at the corners. The facings of the shell are dissimilar to maximize their efficiency, according to the loads acting on each facing. This approach enables a designer to optimize the structure by maximizing the load-carrying capacity or minimizing the weight. The formulation includes the following developments:
1. Global theory of a sandwich shell composed of rectangular and cylindrical sections. Equations of motion are formulated based on a first-order shear deformable version of Sanders’ shell theory.
2. Theory for local deformations and stresses in the facings. The facing is treated as a thin geometrically nonlinear plate or shell on an elastic foundation using von Karman’s approach. The elastic foundation represents a support provided by the opposite facing.
3. An outline of an enhanced micromechanical constitutive formulation based on the incorporation of the effect of the thermomechanical coupling on the material properties and temperature.
Bending Stress Reduction Through Mid-Plane Asymmetry in a Composite Sandwich Shell
Authors: Chen Zhaohui , Vinson Jack R. 
Published: January 2022

Abstract
For shell construction of complex shapes, loads such as a uniform internal pressure cause significant bending stresses which are added onto the membrane in-plane stresses that are produced. For these constructions, mid-plane asymmetry of the sandwich or laminate shell can be used effectively to minimize the bending stresses and deformations, due to the bending-stretching coupling effects of the asymmetric construction. As an example, a complex cylindrical shell is studied wherein flat sides are connected by circular comer 90° shell segments, a cross-section that can be effectively used for the fuselages of large transport aircraft.
Compressive Failure of Debonded Sandwich Beams
Authors: Avery John L. , Narayanan Manickam , Sankar Bhavani V. 
Published: January 2022

Abstract
Compression tests were performed on debonded sandwich beams made of graphite/epoxy face-sheets and aramid fiber honeycomb core. The sandwich beams were manufactured using a vacuum bagging process. The face-sheet and the sandwich beam were co-cured, thus the excess resin from the graphite/epoxy prepregs was used to bond the face-sheet and the core. Delamination between one of the face sheets and the core was introduced by using a Teflon® layer during the curing process. Axial compression tests were performed to determine the ultimate load carrying capacity of the debonded beams. Double Cantilever Beam tests were performed to determine the fracture toughness of the face-sheet/core interface. It was concluded that linear buckling analysis was inadequate for predicting the ultimate loads. A post-buckling analysis was carried out using a nonlinear plane finite element model of the sandwich beam. The ultimate loads predicted by the finite element model were reasonably good for specimens with long delaminations.
Hydrofoil Design and Optimization for Fast Ships
Authors: Besnard Eric , Schmitz Adeline , Kaups Kalle , Tzong George , Hefazi Hamid , Kural Orhan , Chen Hsun , Cebeci Tuncer 
Published: January 2022

Abstract
The paper presents a multi-disciplinary design/optimization method for the conceptual design of a hydrofoil based fast ship. The method is used to determine the maximum achievable lift-to-drag ratio (L/D) of an isolated foil-strut arrangement (hopefully greater than 50) at high transit speeds (greater than 75 knots) while lifting masses of 5,000 and 10,000 tons. First, the tools necessary for the study are presented. They comprise a panel method to compute three-dimensional flows around arbitrary configurations with a model for the free surface, a foil cross-section optimization tool, a strut cross-section design tool, and a structural analysis tool. The computational tools are then integrated into a multi-disciplinary design/optimization approach, which is applied to the design of single foil and biplane configurations. Results show that the goal of L/D = 50 is achievable for 75 knots (assuming that techniques can be developed for reducing the skin friction drag to a quarter of its nominal value) and, that for 90 knots, L/D ratios around 45 can be reached. The corresponding break horsepower requirements for 10,000 tons are around 130 khp and less than 200 khp, respectively.
Modeling of a Magnetorheological Fluid Damper Using Coaxial Cylinder Analysis
Authors: Falah Abdulazim H. , Clark William W. , Phule Pradeep P. 
Published: January 2022

Abstract
This paper presents the modeling and experimental testing of a magnetorheological (MR) fluid damper. The damper consists of a main cylinder and piston rod that pushes MR fluid through a very small clearance between the piston and the sidewalls of the cylinder. Magnetic coils are wrapped around the outside of the cylinder to create the magnetic field. The damper model is developed based on analysis of the fluid flow through the annulus between the coaxial piston and cylinder. Newtonian and Bingham shear flow mechanisms are used in the model, which is validated through experimental testing.
Parametric Analysis of Thermally Enhanced BGA Reliability Using a Finite-Volume-Weighted Averaging Technique
Authors: Cheng Hsien-Chie , Chiang Kuo-Ning , Chen Chao-Kuang 
Published: January 2022

Abstract
As the eager demand for high power-handling capability in smaller packages, thermally enhanced BGA (TEBGA) packages provide a very attractive solution in improving the poor thermal performance problems of conventional over molded plastic BGA packages. In this study, with solder joint reliability in concern during the initial package design stage, an engineering empirical approach using a finite-volume-weighted averaging technique is applied for characterizing the strain concentration field around the corners of solder joints due to a dramatic geometry/material change. Furthermore, a parametric finite element analysis is performed over number of geometry/material design parameters to investigate the dependence on the fatigue lives of the thermally loaded solder joint in a typical TEBGA assembly. Through the parametric design together with a rational characterization of the fatigue lives of the solder joints, the reliability characteristics of the thermally enhanced BGA package can then be effectively identified.
Analysis of Process Yield in Low Cost Flip Chip on Board Assembly Processes
Authors: Thorpe Ryan , McGovern Lawrence P. , Baldwin Daniel F. 
Published: January 2022

Abstract
As a concept to achieve high throughput low cost flip chip on board (FCOB) assembly, a process development activity has been undertaken implementing next generation flip chip processing based on large area underfill printing, integrated chip placement and underfill flow, and simultaneous solder interconnect reflow and underfill cure. The goals are to demonstrate feasibility of no flow underfill materials and the high throughput flip chip process, identify the critical process variables affecting yield, and analyze the effects of the process on different underfill materials. Reported in this work is the assembly of a series of test vehicles to assess process yield and process defects. The test vehicles were assembled by dispensing a controlled mass of underfill material on the chip site, followed by alignment and placement of the chip onto the substrate pads, inducing a compression type underfill flow. Next, the assemblies were reflowed in a commercial reflow oven in an air atmosphere to simultaneously form the solder interconnects and cure the underfill. A series of designed experiments identified the critical process variables to be underfill mass, reflow profile, placement velocity, and underfill type. Of particular interest was the fact that different underfill materials exhibited an affinity for unique reflow profiles to minimize process defects.
Automatic Warpage Measurement of Advanced Packages by Optical Method
Authors: He Xiaoyuan , Dai Jiabin , Liu Sheng 
Published: January 2022

Abstract
Optical techniques provide non-contact, full field measurement for the shape and deformation induced thermally mechanically. In this paper, a new portable projected grating moiré system, recently designed and built for component level warpage measurement, is presented and demonstrated. The system is coupled with an environmental chamber for real time measurement during thermal loading. Within a 50 mm square range, a few microns shape and out of plane deformation can be resolved with a standard CCD camera. An imaging analysis software is developed for automatic deformation measurement. Results on a plastic BGA (ball grid array) are reported. This new technique allows precision measurement of warpage, providing valuable information on packaging reliability, manufacturing process, and modeling validation.