bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Topology and Finite Element Shape Optimizations in the Design of a Pusher for a Crimp Machine
Authors: Krishna Murali M. R. 
Published: January 2022

Abstract
Topology and shape optimization techniques have been applied in combination to design a pusher for a crimp machine. Preliminary topology optimization directed us to do sizing optimization. Topology optimization was again applied to a plate version of the pusher to find out the best form of cut out to reduce its weight further. Shape optimization was then used to find the optimum size of this cut out. The results were verified with solid finite element analysis. In conclusion, both weight and stresses have been brought down drastically. Thus the concept of using both topology and shape optimization has been proved to work successfully with pusher design.
Radiated Noise From a Clamped Circular Plate-Shaft System
Authors: Park Chan Il , Grosh Karl 
Published: January 2022

Abstract
In this paper, a model problem for helical gear system dynamics is studied. The model problem consists of a shaft coupled to a plate through a bearing stiffness. Gear forces are modeled as a longitudinal excitation of the shaft which in turn drives the gear housing through the bearing. In this study, the shaft is modeled as a rod, while the bearing is modeled as a spring only supporting longitudinal forces. The gear housing is modeled as a clamped circular plate. Transfer functions from the shaft to the circular plate are analytically derived, using a spectral method along with four pole parameters. Finally, radiated noise is computed, using the acoustic relations due to plate surface vibration.
Yield Function for Porous Metals With High Pressure Gas Pores
Authors: Ahmed Shatil S. , Alam M. K. , Gunasekera J. 
Published: January 2022

Abstract
To reduce weight while maintaining high specific strength, Structural Porous Metals (SPM) are being developed. These materials are alloys containing an inert gas at very high pressures in distributed pores. The pores of gas are incorporated into the SPM during processing. Since the pores are closed at high pressures, the material can be processed by standard methods such as rolling or forging without collapsing the gas pores. This paper deals with the determination of the yield stress of these structural porous metals. The yield function is calculated by calculating the energy needed to deform the material to the yield point. In the case of SPM, the yield function must include the work needed to deform the gas pores as the material yields. The energy of deformation for the gas in the pores is evaluated according to the ideal gas law. The result of the analysis is then compared with classic yield functions for monolithic alloys.
The Effect of Annealing, Overheating, and a Sintered Porous Coating Thermal Treatments on the Fatigue Properties of Ti-6.0wt.%Al-4.0wt.%V ELI Alloy Plate Specimens
Authors: Fragomeni James M. 
Published: January 2022

Abstract
The primary objective of this investigation was to determine the effect on the mechanical and fatigue properties induced by sintering powder on Ti-6wt.%Al-4wt.%V ELI (Extra Low Interstitial) alloy substrates as compared to annealing, and overheating thermal treatments. Fatigue tests were conducted using a variable speed plate fatigue machine on various specimens in the different thermally-treated conditions so that a comparison study of the fatigue characteristics could be performed. The heat treatments, which included as-annealed, as-overheated, and sintered porous-coated, were performed on the plate fatigue specimens prior to testing in the variable speed fatigue plate machine. A comparison study of the fatigue results/properties of the samples subjected to the three thermal treatments revealed that the annealed specimens exhibited superior fatigue resistance as compared to the as-overheated and porous-coated samples. However, a substantial decrease in the fatigue resistance of the porous coated sintered to the as-overheated thermal treatment was not evidenced. It was determined that the decrease in the fatigue resistance of the as-overheated, as compared to the annealed heat treatment, was a result of an increase in the macroscopic grain size. Furthermore, for the porous-coated specimens, it was determined that the presence of stress concentrations at the surface irregularities of the sintered bond sites resulted in the decrease fatigue resistance. It was found, from optical metallography on the sintered porous-coated samples, that microscopic fatigue cracks originated at the necked regions of both the particle-substrate interface and the particle-particle interface. From these findings it was determined that the fatigue cracks at the particle-substrate interface contributed to the ultimate fatigue failure of the sintered porous-coated plate fatigue specimens.
Design of Experiments Procedure to Optimize Feedrate in Wire Electrical Discharge Machining
Authors: Billatos Samir B. , Ricci Gregory M. 
Published: January 2022

Abstract
Wire Electro-Discharge Machining (WEDM) is a material removal process that incorporates heat generation through electrical energy and mechanical movement to produce finished designs in electrically conductive workpieces. The WEDM workcenter used in this research is a JAPAX 4G. The unit uses nozzles to guide the wire and apply the dielectric fluid to the workpiece. The wire is the conductive electrode and the dielectric fluid produces a localized ionized field between the workpiece and the wire. The dielectric fluid also, clears the debris and cools the wire. The most common problem in WEDM is the optimization of cycle times. The amount of time needed to produce a finished part determines the profitability of the workcenter. Industry is continually searching for procedures to decrease cycle times and increase profit. This research uses a design of experiments (DOE) method to optimize the WEDM process.
The key parameters of the WEDM process are modified during the DOE trials. The results are applied to produce an optimal machining condition. The three conditions: Manufacturers Settings, E-Chip Settings, and Optimized Settings are used to produce the rough-cut of three identical designs. The rough-cut is the first pass to produce a finished workpiece. It is during this pass that material removal rate and the risk of wire rupture are the greatest. The overall cycle time is mainly impacted by the time required to perform the rough-cut. The three designs produced are examined for surface finish. The key parameter settings that are used during the rough-cut must not produce a surface finish that requires the addition of cutting passes to produce the final design. Also, the risk of wire rupture during the rough-cut must be acceptable. If wire rupture were to occur during the rough-cut then all benefits of increased speed are lost.
Potential of Porous Microcellular Polymers in Biomaterials Research
Authors: Kumar Vipin 
Published: January 2022

Abstract
Many different materials, both polymers and metals, are used in various applications inside the human body, such as pacemakers, hip joints, heart valves, tooth implants, lenses, drainage shunts, etc. Although the materials undergo extensive evaluation for ‘biocompatibility’, the definition for which continues to evolve, the body seldom welcomes the foreign matter. It has been found that regardless of the type of man-made material, the body builds a wall around it, and encapsulates it with a fibrous material. Thus, the material is basically rejected by the live cells. This phenomenon is responsible for a variety of complications including infections that are sometimes fatal, and prevents or prolongs proper healing.
Dielectric Characteristics of a Relaxor 0.9PMN-0.1PT Synthesized With Hot and Cold Pressing
Authors: Tang F. , Chinkhota M. , Brown W. D. , Wang J. T. , Lian K. 
Published: January 2022

Abstract
Two different processing methods were employed, hot pressing and cold pressing for fabricating Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ceramic bulk samples, which could be used in the applications of electromechanical actuators in smart material system and structures. The dielectric constant, dielectric loss of these samples versus frequency and temperature were measured and analyzed.
Modeling Nonlinearities in Piezoceramics Associated With Polarization Switchings
Authors: Fotinich Yevgeniy , Carman Gregory P. 
Published: January 2022

Abstract
Piezoelectric materials exhibit nonlinear behavior when subjected to large electric fields. This strong nonlinear material behavior is induced by polarization switching (i.e., change of the polarization direction). In this paper, a nonlinear finite element code for a coupled electro-mechanical problem is presented to model polarization switchings. An isoparametric plane strain four-node element with nodal displacements and voltage as degrees of freedom is used to approximate the geometry. The element incorporates two types of polarization switching: 90° and 180°, where electric flux is used as a switching criterion. Three cases are studied in this paper: a partially electroded specimen simulating 180° polarization switching, a fully electroded specimen simulating 90° switching and a plate containing a void. The analytical results are compared with experimental data obtained from a Moiré interferometer. Comparison between experimental data and theoretical results indicates reasonable agreement between the two suggesting that the correct physics is incorporated in the analytical model.
Development of a Low Frequency High Stroke Proof Mass Actuator With Composite Members
Authors: Dunn Barry , Paine Jeff 
Published: January 2022

Abstract
A design study and hardware evaluation was performed on the use of piezoelectric transducers in an innovative flexure mechanism based actuator to provide control forces for low frequency applications. The specific design concept involves the use of a hybrid composite/solid-state flexure mechanism to create a proof mass actuator (PMA). The new actuator merges the benefits of solid-state piezoelectric actuator technology with low stiffness, composite material, fatigue resistant kinematic elements and low friction sapphire bearings. The novel use of low stiffness composite materials was used to provide greater stroke levels than a pre-existing flexure-based solid-state actuator design giving larger output forces in a similarly sized package. The flexible curved composite components allow a lower natural frequency and therefore higher output forces at lower frequencies. The use of synthetic bearings for the composite arm provides an effective reduction in the resonant frequency of the device. This is due to the change in the composite arm’s boundary conditions from a quasi fixed-fixed to a pinned-pinned condition. The use of different mechanism geometries showed that the construction of the composite arm allows the response of the PMA to be tailored for different operational ranges. The new technology discussed herein is a step ahead of current actuation systems because it combines the attributes discussed above into a mechanism that yields reliable, simple to implement actuation.
Analysis and Control of Mesoscale Actuator Systems
Authors: Kiely Edward , Washington Gregory , Song Jun-Kyung 
Published: January 2022

Abstract
A great deal of literature exists on the modeling and control of piezoelectric materials used as microscale actuators. These actuators take advantage of the converse piezoelectric effect to produce deflections on the order of tens of several microns. Typical applications include active noise control, active vibration control, platform actuation, and many others. Recently the design of mesoscale actuators (deflections from 1 mm – 15 mm) has been a topic of study for many researchers. This study deals with the design and control of a mesoscale actuator comprised of stacked piezoelectric Rainbow wafers. The advantages of using piezoelectric materials for actuation include low power usage, fast response times, accurate displacement, and low cost. However, these advantages do not come without a tradeoff. The effects of hysteresis and creep, while apparent in traditional microscale piezoelectric actuators, are magnified with the increased deflection of these new actuators. Because of this fact, control of the actuator – plant system becomes more difficult. In addition, the uniform manufacture of uniformly spherical Rainbows is difficult, introducing the problem of inconsistent behavior among individual Rainbows. Although numerous, these problems can be overcome by employing various dynamic control techniques. The work in this study presents and experimentally verifies a model of a Rainbow actuator based on shell theory. The system is then controlled using both classical and intelligent control techniques. In addition hardware and circuitry issues are explored.
The Effect of Model Uncertainty on Magnetorheological Fluid Damper Based Systems Under Feedback Linearization Control
Authors: Marathe Sameer S. , Wang K. W. , Gandhi Farhan 
Published: January 2022

Abstract
This paper is concerned with the effects of magnetorheological (MR) fluid damper model uncertainties on system stability, when local feedback linearization schemes are utilized. The objectives of the research are to characterize such effects, and develop a robust control law for given uncertainty bounds. First, deterministic functions are used to represent the possible deviations between the actual MR damper force and the force predicted by the model. Limit cycle behavior is predicted using the Describing Function Method and parameters influencing the limit cycle characteristics are identified. An effort is then made to derive the worst-case model deviation, given the bounds on the possible model uncertainties. Based on such results and the limit cycle analysis, a robust feedback linearization controller is synthesized to eliminate the limit cycle instability.
A Bi-Axial Active Boring Tool for Chatter Mitigation
Authors: Redmond James M. , Barney Patrick S. 
Published: January 2022

Abstract
This paper summarizes results of metal cutting tests using an actively damped boring bar to suppress regenerative chatter. PZT stack actuators were integrated into a commercially available two-inch diameter boring bar to suppress bending vibrations. Since the modified tool requires no specialized mounting hardware, it can be readily mounted on a variety of machines. A cutting test using the prototype bar to remove metal from a hardened steel workpiece verifies that the actively damped tool yields significant vibration reduction and improved surface finish as compared to the open-loop case. In addition, the overall performance of the prototype bar is compared to that of an unmodified bar of pristine geometry, revealing that a significant enlargement of the stable machining envelope is obtained through application of feedback control.
Analysis of Active Doubly Curved Antenna Structures
Authors: Yoon Hwan-Sik , Washington Gregory 
Published: January 2022

Abstract
Recently, aperture antennas that have the ability to change their reflector shape through the usage of piezoelectric actuators have been studied. The results show that those antennas can exhibit beam steering and beam shaping in the far-field. However, the previous studies have been confined to cylindrical shape antennas. This study examines the use of “doubly curved” antenna structures to achieve better performance in controlling an antenna’s coverage area. The spherical antenna is modeled as a shallow spherical shell with a small hole at the apex for mounting. Following Reissener’s approach, a stress function is introduced and two governing equations are derived in terms of the stress function and the axial deflection. Next, the amount of deflections are evaluated from the calculated stress function and the axial deflection. As actuators, four PZT strip actuators are attached along the meridians separated by 90 degrees respectively. The force developed by the actuators are expanded in Fourier series and fed into the governing equations as boundary conditions at the outer edge. Finally, the Deflection vs. Applied Voltage is calculated analytically and its effect on the far-field radiation is given.
An Investigation of Delaminated Smart Composite Plates for Damage Detection
Authors: Chattopadhyay Aditi , Dragomir-Daescu Dan , Nam Chang-ho 
Published: January 2022

Abstract
A refined modeling technique is developed to analyze the effect of delamination on a composite plate with piezoelectric actuators. The analysis uses a refined displacement field, which carefully accounts for both the presence of delamination and distributed actuators. The effect of delamination is investigated under both static and dynamic conditions. The analysis is implemented using the finite element method. Numerical results presented indicate the significant changes in mechanical parameters due to a small delamination. These results can be useful for on line damage detection.
3D Computational and Experimental Fluid Dynamics Analysis for the Automotive Catalytic Converter
Authors: Fu Xiaodong , Lambert David W. , McLaren George S. , Treacy David R. , Then Paul M. 
Published: January 2022

Abstract
Numerical and experimental fluid dynamics analysis has been performed for the automotive catalytic converter under isothermal condition focusing on two primary problems of catalytic converters: (1) the low conversion efficiency; (2) high pressure drop. The K-ε turbulent model based on the eddy viscosity model combined with the fluid flow model in porous media was used as the physical governing equations. The numerical results agreed with the experimental data obtained by LDV and hot wire anemometer. Some insights and optimization design concepts obtained in the present work provide valuable information to the converter designer.
Experimental Determination of the Viscous and Inertial Coefficients in Highly Porous Metal/Ceramic Foams
Authors: Jones Stanley T. , Sommer Martin , Rios-Forscht Alexander , Catton Ivan 
Published: January 2022

Abstract
An experimental program has been conducted to characterize the behavior of a series of highly porous, reticulated metal/ceramic foams composed of silicon carbide. Using information from the manufacturer, an expression was developed by which the volumetric porosity was determined. The range of porosities investigated was 0.72 to 0.90 for most materials investigated.
Flow experiments were conducted to determine the pressure loss as a function of the pore Reynolds number. By implementing a form of the Kozeny-Carman equation for viscous pressure loss, the specific surface area was determined from low flow rate measurements. Air was blown through a 2” diameter circular cylinder of porous media of varying lengths. The mass flow rate and pressure difference were measured under steady flow conditions. Based upon a Reynolds-Forchheimer representation of the pressure loss, these measurements allowed for determination of the viscous and inertial pressure loss coefficients. Based upon these results, a series of expressions for the Fanning friction factor as a function of pore Reynolds number are proposed for this class of porous media.
Parallel Computing Issues in a Particle-Continuum Model for Two-Phase Flows
Authors: Sigurgeirsson Hersir 
Published: January 2022

Abstract
We describe a model for two-phase flows where droplets are considered as point particles interacting with the flow, in which they are embedded, and each other. The particles interact with the flow through interchange of mass, momentum, and energy, and with each other through collisions. We investigate algorithms for computer implementation of the model using appropriate data structures to efficiently detect and handle collisions between particles, and to stably and accurately describe the particle-continuum interaction. Parallel implementation of the model poses several challenging problems, such as load balancing the particle portion of the computation and sharing data between the continuum and particle parts. We address these issues through experiments on an SGI Origin2000 and develop some simple models of computational cost.
Parallel Algorithm for the Solution of High Order Discretization of Elliptic PDEs
Authors: Mateescu Gabriel , Ribbens Calvin J. 
Published: January 2022

Abstract
We present a parallel preconditioned-GMRES algorithm for solving second-order elliptic PDEs defined on rectangular domains with Dirichlet and Neumann boundary conditions, and discretized with piecewise Hermite bicubics. The parallel performance of the algorithm is assessed by way of numerical experiments.
An Efficient Finite Element Method for the Representation of Fluid Structure Interaction in Large Structural Transient Dynamic Analyses
Authors: Harkness Alexander W. , Schwirian Richard E. 
Published: January 2022

Abstract
A finite element model method was developed to evaluate fluid structure interaction between core support structures and reactor coolant during rapid Loss Of Coolant Accident (LOCA) conditions in Pressurized Water Reactors (PWR’s). The hydraulic behavior of the reactor coolant was modeled using a series of contained fluid elements linked to the structural elements using linear constraint equations. An advantage of this method is the significant reduction in the number of contained fluid elements required to accurately represent the fluid structure interaction. A large volume of fluid may be modeled by a single contained fluid element without compromising detail in the finite element representation of the structure. This three-dimensional finite element method represents an expansion of the two-dimensional methods presented by Riddell and Schwirian (1983).
To provide verification of the method, finite element analysis results produced for a benchmark analysis were compared directly to a series of hydraulic pressure pulse tests performed previously. The typical hydraulic pulse evaluated had a pressure ranging from 0 to 1200 psig with a duration of less than 40 msec. Good agreement was observed between test and analysis results.
Standardized Geometry Rules for Fluid Flow Analysis Software Applications
Authors: Wilson Roger D. 
Published: January 2022

Abstract
Standardized geometry protocol software is needed for use in conjunction with hydraulic analysis software.
Hydraulic models are used to analyze and solve steady-state and transient problems in many systems.
The owner of such systems often faces the need to utilize less rigorous modeling and problem solving techniques. This is due the high cost of having to repeatedly develop a geometric model of the same system for different hydraulic software applications because of different rules and criteria governing system modeling.
Instead a geometry model of such systems using a standard convention should be developed. All programs would recognize and be compatible with the standard. Such standardization would benefit both the owner and the software manufacturers.
Conceptual ideas about the standardized geometry protocol software are presented.
The protocol software sponsor must be a large organization such as ASME or EPRI to manage the effort through its development.