bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monte Carlo Simulation of a Partially Submerged Compliant Structure
Authors: Adrezin Ronald S. , Benaroya Haym 
Published: January 2022

Abstract
The response of a single-tendon tension leg platform subjected to stochastic wave and current loading is presented with a planar motion assumption. The tension leg platform will oscillate about its vertical position due to ocean waves. Current will cause a tension leg platform to oscillate about an offset position rather than its vertical position. This offset in the surge direction has a corresponding set down, the lowering of the hull in the heave direction, which increases the buoyancy forces. This results in a higher tension in the tendons than if the tendon and hull were in a vertical position. In prior papers the equations of motion and forcing functions were fully developed. The tendon and hull are both assumed to be cylindrical and therefore Morison’s equation was applied. In this paper, a Monte Carlo simulation was performed on the drag and inertia coefficients in Morison’s equation. A uniform random distribution of coefficients was selected from 0.6 to 2.0 for each coefficient. Twenty computer simulations were implemented for each coefficient. The response showed that the offset position and the amplitude are both dependent on the drag coefficient. The surge of the hull shows a maximum offset approximately three times greater for the coefficient that resulted in the maximum displacement than the minimum. The response did not show a significant dependence on the inertia co-efficient, however, this is not necessarily true for unsteady current, large hull and tendon diameters, ocean wave frequencies greater than 1 radian/second, and low current velocity.
A Solid-Fluid Coupling Computing Method for Design High Speed Spindle Cooling System
Authors: Liu D. S. , Lee T. C. 
Published: January 2022

Abstract
High speed spindle is the key component for high precision machine center. The optimum design of spindle cooling system have to achieve to avoid the high heat produce by the build-in motor that can make great damage to the spindle bearing systems. This paper presents a new solid-fluid coupling computing method for design high speed spindle cooling system. Energy equation has been formed for a control volume within the cooling channel to described the heat absorbing by the coolant moving in a constant speed. Finite different method is applied to solve temperature rising in the coolant and coupled with a 3-D finite element structure heat transfer program which can solve temperature distribution due to heat produce from build-in motor. An experimental testing setup is using to verify this solid-fluid coupled program. The numerical results agree well with experimental data. The effectiveness of straight heat-pipe-type cooling system and helical heat-pipe-type cooling system are compared by applied this methodology. The numerical methods developed in this research can offer the spindle designer a new tool to improve spindle cooling system design.
Designing Machine Tools to Minimize Life Cycle Cost
Authors: Carter Michael F. 
Published: January 2022

Abstract
This paper describes a methodology used in the design of manufacturing machines to minimize life cycle cost. Life cycle costs include design, construction, installation, planned maintenance, repair, disposal and lost production caused by breakdowns. Studies have suggested that maintenance accounts for half of life cycle cost, and the primary focus of this methodology is to reduce repair and maintenance costs. This methodology has on average resulted in a 10 percent savings in capital investment, a 50 percent reduction in lifetime maintenance costs and a significant improvement in up-time.
Design for Quality Approach to Improve Surface Roughness in Milling Operations
Authors: Abdou G. , Basaly N. A. 
Published: January 2022

Abstract
Tooling related malfunction is of particular concern, since tooling condition can cause loss of dimensional part accuracy and loss of the required surface finish. Out of specifications surface parameters will often be confined to less than quality making features and hence affect manufacturability. There is an eminent need for a methodology that enables process designers to evaluate and improve the quality manufacturability of the milling process before machining. This paper describes a methodology of design for quality manufacturability that enables product designers to evaluate, quantify and improve surface roughness in the design stage for milling operations. Different experiments have been conducted to measure cutting forces and surface roughness parameters under dry cutting conditions. The relationships between different operating parameters to the cutting force and surface roughness parameters were examined through extensive experimental work. Different relationships have been developed between five surface roughness parameters and three operating parameters. Further analysis has been conducted on the cutting force pattern: seasonal pattern, nonlinear trend and peak. The results generated from the study are very important for the parameters’ design of manufacturability for the milling operation. The basis for the design for quality is a set of common classes of quality defects (errors), and a set of factors that influence the occurrence of the less quality. The concept of quality errors and the derivation of the index matrix are presented.
A Stress and Relative Density Dependent Dynamic Compliance Spectra Model of the Creep Response of Microcellular Polycarbonate
Authors: Armstrong William D. , Kumar Vipin 
Published: January 2022

Abstract
The present paper reports a new stress and relative density dependent discrete dynamic compliance spectra method which may be used to model the creep behavior of nonlinear viscoelastic microcellular materials. Comparisons between model calculations and experimental measurements show that the model exhibits excellent quantitative agreement at all experimental stress-relative density states. A designer may use the present method to predict the creep strain resulting from a broad range of specific stress-relative density combinations, or to identify relative density ranges over which the material provides relatively stable creep properties.
Bubble Growth in Thermoplastic Foam Extrusion
Authors: Ramesh N. S. 
Published: January 2022

Abstract
A condensed review will be presented regarding the bubble growth study. A modified model fitting to foam extrusion system will be discussed. The improved model focuses on the influence of blowing agent on bubble growth during thermoplastic foam extrusion. Extrusion has been conventionally used for producing low-density foam sheet and rods with physical blowing agents in the last decades. Foam nucleation, bubble growth, and cell coalescence are the three major events in the foaming process. Only the bubble growth study is addressed here. The bubble growth is influenced by the concentration-dependent blowing agent diffusion coefficient, transient cooling of the expanding foam, influence of blowing agent on polymer viscosity, and the escape of blowing agent from the surface of the foam. The blowing efficiency is affected by the escape of gas from the cells closer to the surface of the foam. Previous models in the literature do not consider these significant influences. A modified model will be presented accounting for those more subtle effects. In addition, a new experimental technique will be described to collect experimental bubble growth data. Predictions of the new model reasonably agree with the experimental data.
Foaming of Poly(Ethylene Terephthalate) Modified With Tetrafunctional Epoxy
Authors: Japon Sonia , Boogh Louis , Leterrier Yves , Månson Jan-Anders E. 
Published: January 2022

Abstract
A reactive process is developed to extend the recycling of poly(ethylene terephthalate) (PET) into high-value applications, in particular into foam core sandwich structures. To achieve a cellular structure, a high extensional viscosity is required to prevent foam collapse during the final stabilisation phase of the extrusion process. This is obtained by reacting PET with tetrafunctional epoxy-based modifiers, which induce branching and a certain amount of crosslinking. The modification of the chemical architecture leads to a 50-fold increase in the apparent extensional viscosity. With these modified materials closed-cell foams are obtained using carbon dioxide as a foaming agent.
Some Research Activities and Opportunities in Smart Materials and Structures
Authors: Chong Ken P. , Larsen-Basse Jorn 
Published: January 2022

Abstract
Adaptive, or “smart” materials, materials systems, and structures have been the focus of considerable research during the past twenty years or so, and have increasing promise for many different applications. We are here presenting a small sampling of some of the engineering-related research in this area that NSF has supported in the recent past or is currently supporting. We specifically focus on two diverse general topic areas with which we have been associated: civil infrastructure systems structures and engineered surfaces of materials. We make some personal observations on what we think are some of the emerging research opportunities and needs. A major driver for research in this area will probably be the search for various engineering “fixes” for environmental problems that our technology has created and the need for closer control with processes of all sorts. Development will be supported by advances in distributed intelligence, MEMS, nano-technology, digital simulation, modeling, materials science, etc.
Experimental Results for Magnetostrictive Composites
Authors: Duenas Terrisa A. , Carman Gregory P. 
Published: January 2022

Abstract
This paper contains experimental results for magnetostrictive composites containing Terfenol-D (Tb0.3Dy0.7Fe2) particulate embedded into an epoxy binder. Composites of 10% to 40% volume fraction were manufactured to produce pseudo 1-3 magnetostrictive composites. In an absence of a mechanical preload, the 20% sample produced strains exceeding 1000 microstrains; the larger volume fraction samples — i.e., 30 and 40% achieved only half of this value. Under an applied preload both the 30% and 40% samples produced strain output exceeding 1000 microstrains. Analytical results are presented to explain this experimental data.
A Large Stroke, Nanometer Precision X-Y Stage for Lithography
Authors: Jones Lowell D. , Paine Jeffrey S. N. 
Published: January 2022

Abstract
The state-of-the-art in the microelectronics industry is being pushed primarily by two motivations: the demand for more circuitry etched per unit area and the demand for higher throughput. Both of these needs can be met by an increase in the speed and/or the resolution of lithography positioning equipment. Presented herein is an attempt to develop an innovative X-Y stage design through which control of positions on the order of nanometers will be possible while simultaneously increasing stroke length to 300 mm per axis, the maximum speed to 1 m/s, and the turnaround time to under 100 ms. The proposed design will approach this problem by incorporating a macro-micro positioner analogous to an audio “woofer-tweeter” arrangement for each axis of the stage. This approach will allow for a decoupling of the positioners coarse and fine motion properties simplifying components and design of the entire system. While this approach is not unique to lithographic stages it does offer the innovation of using a piezoelectrically actuated flexure mechanism for the tweeter as opposed to the typically employed magnetic levitation based tweeter. Piezoelectric actuation is superior to voice coil actuation in this application due to its simplicity, lower mass, and most importantly, its low heat generation. Two additional features are also incorporated in the design for the minimization and localization of heat generation. The first feature is configuring the stage in a mechanically parallel fashion in order to minimize parasitic inertia and locate the woofer’s actuators at ground. The second feature is the selection of rotary motors to drive the linear woofer stage through cable transmissions.
Control of Random Vibrations of Composite Plates With Piezoelectric Actuators
Authors: Lee Yiu-Yin , Mei Chuh , Huang Jen-Kuang 
Published: January 2022

Abstract
A study of the use of H∞ control design to suppress the vibrations of composites plates embedded with piezoelectric actuators under random loading is presented. The finite element method is employed to obtain the dynamic equations of a plate vibration of fully coupled structural and electrical nodal degrees of freedom (DOF). The modal reduction method is adopted to reduce the finite element equations into a set of modal equations with fewer DOF. The modal equations are then employed for controller design and simulation. Results of the modal convergence study of the closed loop systems show that the truncated modes, which are neglected in the control design, deteriorate the controller performance and affect the optimal location and size of the actuator. The vibrations of plates subjected under off-resonant narrow-band excitations cannot be suppressed effectively. The controller shaped with an extra weight function for mitigating measurement noise effect gives better vibration reduction performance.
Comparative Assessment of Optimal Control Methods With Integrated Performance Constraints
Authors: Smith Malcolm J. , Koko T. S. , Orisamolu I. R. 
Published: January 2022

Abstract
The relative performance of optimal vibration control methods is investigated within the context of integrated finite element modeling of piezothermoelastic structures. An IMSC and a LQR optimal control method are modified to include explicit performance constraints related to the transient settling time and steady-state gain of the modal response. When this approach is applied to the IMSC method, the result is a pole placement technique. But when it is applied to the LQR method operating in a modal subspace, the result is a method incorporating both optimal and pole placement features. The two methods are compared by means of a transient response analysis of an aluminum strip with piezoceramic sensing and actuating patches. For identical performance constraints and using identical modal subspaces, it is found that maximum actuator voltages and their distribution vary according to the control design method and the number of modes under control. In particular, it was found that the maximum actuator voltages are less for LQR than for IMSC. This is attributed to difficulty in controlling the second bending and first torsional modes of the strip independently. It is also found that for a given number of controlled modes, the maximum actuator voltage varies in a manner approximately inversely proportional to the settling time.
Evaluation of Fiber Optic Sensors for Measuring Strain in Aircraft Applications
Authors: Tarter Jim , Sirkis Jim , Boyer Tom 
Published: January 2022

Abstract
This paper describes the application of in-line fiber etalon (ILFE) fiber optic sensors to the measurement of strains generated in an aircraft system. Single channel phase tracker and active homodyne demodulation schemes were tested simultaneously, but with different ILFE sensors. Cantilever beam and full scale strain measurements compared well with resistance strain gage measurements. This program gave insight to further applications of advanced optical fiber sensors to the harsh environments typical of in-service aircraft systems.
Crash Energy Management of Aluminum Components
Authors: Weinhold Volker , Baccouche Mohamed Ridha , Hasan Abid 
Published: January 2022

Abstract
Automobile manufacturers increasingly desire to produce vehicles that are not only fuel efficient and environmentally friendly, but also, light weight and structurally safe. Vehicle weight plays an important role in fuel consumption and is relatively effected by the size of structural components and powertrain.
The quest to reduce vehicle weight without jeopardizing structure’s crash energy management has lead to investigating materials other than steel, i.e., aluminum, composite, magnesium etc. In this regard, aluminum is the most popular material that is prominent due to its tangible material properties. Aluminum space frame and extruded aluminum components are widely used in the automotive industry, especially in low volume and niche vehicle programs, and in programs where significant weight reduction has to be achieved.
The structural components of aluminum space frame can be designed to achieve high energy absorption under various crash conditions (i.e. full front and offset crash against rigid and deformable barriers). Techniques are available to downgage or reinforce components where needed, so that excellent crash performance (axial collapse as well as local bending) can be achieved within weight targets. This enables for a flexible adjustment of various vehicle architecture parameters (i.e., front rails height, vehicle length and width) which, again, is ideal for low volume approaches.
Generic Tube Crush Program: Crush Tests of Structural Reaction Injection Molded Tubes
Authors: Johnson Nancy L. , Houston Dan Q. , Watling Patrick J. , Lalik Larry 
Published: January 2022

Abstract
This paper documents the structural reaction injection molding (SRIM) portion of a generic crush study of glass fiber reinforced composite tubes conducted by the Energy Management Working Group of the Automotive Composites Consortium (ACC). Static and dynamic crush tests were performed to evaluate the crush performance of square, circular, and rectangular shaped cross-section tubes. Manufacturing of the tubes for this study required feasible processes for production such as resin transfer molding (RTM) and SRIM, in conjunction with rapid preforming and foam core fabrication. Square (55 × 55 mm), circular (63.5 mm diameter), and rectangular (38.1 mm × 71.1 mm) crush tubes had a nominal wall thickness of either 2.54 or 5.08 mm and a length of 230 mm. Dow Spectrim MM364 resin was used for all the tubes in this portion of the study. Seven different fiber architectures were considered ranging from random chopped mat (RCM) to a tri-axial braid. The principal fiber was E-glass with a limited number of tubes being constructed with S-2 glass. A plug-type initiator was used in combination with a 45° bevel on the outside edge of the lead end of the crush tube to ensure progressive crush. Crush tests were performed at −40°C, room temperature, and 82°C. The tubes tested at high temperature were immersed in distilled water for 24 hours prior to heating. Various fiber architectures, wall thicknesses, and temperatures were evaluated for their effect on energy absorption characteristics during axial crush using plug-type initiators. Principle findings were that different fiber architectures can produce significant differences in tube specific energy absorption (SEA), that SEA increases dramatically with increasing tube wall thickness, and that post-curing can increase the SEA of the tubes. Static tests produced higher values of SEA than those measured in dynamic tests for most fiber architectures at cold and room temperatures, while at elevated temperature / humidity, the opposite effect is seen in that static values were lower than dynamic values of SEA.
An Analytical Study of System Variables for Meeting FMVSS 201 Head Impact Requirements
Authors: Zhou Qing , Thomas Mohan P. , Stibich Anne M. 
Published: January 2022

Abstract
A hypothetical acceleration pulse, asymmetric haversine wave, is used to analytically model acceleration pulses of FMVSS 201 head impact tests. This model leads to general relations among a few key variables in head impact tests including Head Injury Criterion (HIC), initial impact velocity, and stopping distance. As a result of this analysis, a preferred design range of stopping distance is identified and HIC sensitivity to impact velocity is revealed. Parameters that can assess energy absorbing efficiency of a head impact countermeasure are defined and discussed. The model may be used to guide the design of vehicle interior trim for meeting FMVSS 201 head impact requirements and has been validated using test and finite element results.
Nonlinear Lumped-Parameter Model of Unconstrained Standing Postured Personnel Subjected to Vertical Upward Shock
Authors: Liu Xinxiang 
Published: January 2022

Abstract
The Standing and seating postures are two kinds of most common working postures in the warship. Therefore we need take these two postures into consideration when we study the biodynamic response and injury prediction of ship personnel subjected to vertical shock motion induced by underwater explosion. This paper will describe a biodynamic model of unconstrained standing postured personnel.
Effect of Distance Between Fins on the Hydrodynamics in a Fin-Tube Heat Exchanger
Authors: Romero-Méndez Ricardo , Sen Mihir , Yang K. T. , McClain Rodney L. 
Published: January 2022

Abstract
In this work we study the hydrodynamics of flow around the tubes of a single-row fin-tube heat exchanger. The study includes numerical analysis using finite elements and flow visualization experiments in a water tunnel. It is found that the nature of the flow is greatly affected by the distance between fins. For small distances, the flow is of the Hele-Shaw type without separation. As the distance between fins is increased, a separated region is formed behind the tube which may become unsteady and lead to vortex shedding. Also affected in a similar fashion by the distance between fins is the horseshoe vortex that exists just upstream of the cylinder.
Reconstruction of Steady Flow Field by Electromagnetic Tomography
Authors: Honda S. , Trächtler A. 
Published: January 2022

Abstract
Magnetic flowmeters, which have been one of the standard instrument to measure flowrate of the liquid with electrical conductivity in industry, were applied to tomographic imaging of flow velocity field, based on the fact that there are no exciting magnetic fields that induce the flow signal proportional to volumetric flowrate free from the flow profile. Previous 2-D reconstruction method is examined through 3-D analysis, and feasibility conditions are clarified.
Geostatistical Analysis of TPH Degradation in Field Soils
Authors: Govindaraju R. S. , Nedunuri K. V. 
Published: January 2022

Abstract
Evaluation of remediation strategies in the field is difficult because of the inherent spatial heterogeneity in the hydraulic and chemical properties of the soil. In this study, total petroleum hydrocarbon (TPH) degradation was monitored over a field site with three vegetative treatment plots, and one control plot undergoing natural attenuation. First-order kinetics were assumed applicable at the local scale. The degradation rates and the initial contaminant concentrations were treated as spatially correlated random fields. Our results indicate the importance of spatial variability for an accurate assessment of phytoremediation in the field.
Comparison of First-Order Turbulent Models’ Predictions of Flow About Steps/Buildings
Authors: Brzoska Michael A. , Stock David E. , Lamb Brian K. 
Published: January 2022

Abstract
Flow over back-facing and front-facing steps and three-dimensional buildings were modeled with the standard k-ε, strain/vorticity modified k-ε, k-ω, and modified k-ω models. Comparisons were made between models and to experimental work (Moss and Baker. 1980). Discussion of reasons for variations in models and deviations from experiments are given.