bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Long Term Durability of Polyphenylene Sulfide Using In Situ FDEMS Sensing and Mechanical Analysis
Authors: Kranbuehl D. , Newby W. , Garrett J. , Gittelson R. , Yang J. , Case S. , Reifsnider K. 
Published: July 2023

Abstract
Current designs for nonbonded flexible pipe used to transport oil and gas from the sea floor on offshore platforms utilize carbon steel wire to maintain axial strength. Polyphenylene sulfide (PPS) graphite tape is one possible replacement in the design of a lightweight, high strength composite flex pipe for offshore oil and gas use. This report discusses work on the use frequency dependent electrical sensing (FDEMS) techniques to monitor the extent of degradation in PPS and use of FDEMS sensing to quantitatively monitor insitu changes in the strength of the PPS during use in the field. This report also addresses the use of “mechanical test” tests to evaluate the long term ability of PPS tape to maintain hoop strength in a high temperature salt water environment.
Assessment of Residual Composite Properties as Influenced by Thermal Mechanical Aging
Authors: Plunkett R. B. , Tsang P. H. , Lesko J. J. , Wood J. D. , Rufin A. C. 
Published: July 2023

Abstract
In this study, two quasi-isotropic carbon fiber-reinforced polyimide material systems, IM7/K3B and IM7/PETI-5, were thermally aged at 163°C (325°F) for up to 3000 hours under a static compressive load. The future goal of this study is to determine the effect of 10000 hours (currently underway) and possibly seven years of aging on these materials. The compressive load was applied using steel fixtures supplied by The Boeing Company. Back-to-back gages on the aging panels monitored compressive strain as well as bending strain. Following aging at 1500 and 3000 hours, ambient residual compression properties were assessed using the IITRI compression test method. Unexposed specimens were also tested to obtain baseline properties for comparison. These results showed that 3000 hours of stressed isothermal aging did not significantly affect the compressive properties of the two composite systems. A slight increase in scatter of the residual strength numbers was observed. Statistical evaluation of the results was used to compute design allowables and quantify changes in scatter. Dynamic thermogravimetric analysis (TGA) tests were used to compare weight loss rate versus temperature results for the different age materials. Preliminary results show different rates of degradation occurring in the different polymer aging histories. In addition to establishing the effect of isothermal aging under load on the compressive moduli and strength of two polymer-matrix composites, this experiment links increasing scatter in residual strength measurements to changing thermogravimetric results.
Buffet Load Alleviation Using Distributed Piezoelectric Actuators
Authors: Moore Jeffrey W. , Spangler Ronald L. , Lazarus Kenneth B. , Henderson Douglas A. 
Published: July 2023

Abstract
Unsteady buffet loads, resulting from high angle of attack maneuvers, cause excessive vibrations in the vertical tail of fighter aircraft. These vibrations increase structural fatigue, reduce service life and reduce availability of the aircraft. Therefore, a need exists to suppress the buffet induced vibrations.
This paper describes an active buffet suppression system designed to reduce the structural response of a full scale fighter tail under buffet loads. The system level design is discussed in detail with particular attention paid to actuator design and distribution. The analysis concludes with an estimate of the system performance based on modeled disturbance rejection. The design successfully reduces the response of the tail within specific design and weight constraints. The Buffet Load Alleviation system consists of induced strain piezoceramic actuators distributed on the surface of the tail. The actuators are driven by a digital programmable controller and a linear amplifier system. Closed loop control is achieved using accelerometers and strain gages located on the tail for the feedback.
Polarization Switching for Ferroelectric Materials
Authors: Park S. B. , Park S. S. , Carman G. P. , Hahn H. T. 
Published: July 2023

Abstract
In this paper we present the results of an experimental study focused on understanding the strain concentrations arising due to nonlinear phenomena associated with polarization switching. A Moire interferometry technique is used to measure the normal and shear strains of a PZT-5H piezoceramics undergoing 180° and 90° switching. These results include the strain concentrations measured between polarized regions oriented 180° and 90° apart. The results show that very large strain mismatches (e.g. as large as 4500 microstrains) occur along the boundary of dissimilar oriented domains, suggesting a source of microcrack initiation and fatigue degradation.
Active Tagging Non-Destructive Evaluation Techniques for Full-Scale Structural Composite Elements
Authors: Chen Zao , Giurgiutiu Victor , Rogers Craig A. , Quattrone Robert , Berman Justin 
Published: July 2023

Abstract
A health monitoring technique is presented for on-site particle tagging non-destructive evaluation (NDE) of a full-scale structural element of advanced composites. Conventional non-destructive evaluation methods are not very effective in monitoring the material conditions of advanced composite and adhesive joints. A technology that has been proposed to enhance the inspectability of advanced composites is the particle tagging technique (Rogers, et al., 1995), (Zhou, et al., 1995). This technique which has been previously demonstrated on small scale, laboratory samples (Rogers, et al., 1996(a)), (Rogers, et al., 1996(b)), (Giurgiutiu, et al., 1996) is now developed to scaled up on full-scale structural elements. The concepts for large scale tagged composite inspection build on the previously developed small scale concepts. The technique relies on comparing changes in local-area mechanical properties of the structure to identify damage. Unlike conventional passive tagging NDE inspection, the technique uses an electromagnet exciter to interrogate tagged composites. A laser Doppler vibrometer is used for high-speed and non-contact surface vibration detection. An accept-reject criteria based on the signature pattern difference of a healthy and a damaged structure is then applied to extract an index of the health of the structural elements. The experimental results of the active particle tagging inspection shows a variation in the dynamic response of the specimens when defects and/or damage are presents. The variation could be used to diagnose and to monitor the integrity of materials.
Controllable Rotary Damper Using Liquid Crystal
Authors: Tani J. , Nakaniwa H. , Ohtomo K. 
Published: July 2023

Abstract
This paper describes an experimental study on the vibration suppression of rotary shaft using liquid crystal. A controllable rotary damper using liquid crystal with nematic phase is proposed and applied to the vibration suppression of a rotary shaft and a pendulum. Two disks were mounted inside a housing, which were attached to rotary shafts. These disks are free to rotate inside and relative to the housing. Damping is introduced by filling the space between housing and disk with liquid crystal, apparent viscosity of which can be controlled by the applied electric field. The results show that the torsional vibration of the rotary shaft, and the free vibration and parametric resonance of the pendulum are suppressed effectively.
Optimal Design of Piezoelectric Actuators for Adaptive Structures
Authors: Moini Hossein 
Published: July 2023

Abstract
Evaluation of the design of piezoelectric actuators for deforming a multi-layered adaptive structure is presented. The system is composed of layers of bimorph piezoelectric actuators. Each bimorph creates a different mode shape in the structure. The moments generated by the actuators are evaluated through a static analysis and by using the superposition of the structure’s normal modes to represent a desired shape. Maximum likelihood estimation combined with the method of simulated annealing have been applied to determine the optimum parameters of the system. Dynamic modeling and analysis is conducted by using the mode-summation method adjusted for a continuous system subject to the piezoelectric actuation. Mode participation factors are evaluated to show how each actuator contributes to a specific mode without a spillover.
Micro-Electro-Mechanical-Systems and Industrial Applications
Authors: Möllendorf Manfred 
Published: July 2023

Abstract
This paper gives an overview of Micro-Electro-Mechanical devices that are in the industrial stage for application in the automotive and the communication industry. We present a monolitic integrated pressure sensor, a massflow sensor and a monolithic integrated acceleration sensor. Also introduced is a novel process for surface micromachining which is offered as a foundry service to companies and universities. In the second part important optoelectrical components for the optical path network will be presented.
A Hazard and Probabilistic Safety Analysis of a High-Level Waste-Transfer Process
Authors: Bott Terry F. , Sasser M. Kent 
Published: July 2023

Abstract
This paper describes a safety analysis of a transfer process for high-level radioactive and toxic waste. The analysis began with a hazard assessment that used elements of What If, Checklist, Failure Modes and Effects Analysis, and Hazards and Operability Study (HAZOP) techniques to identify and rough-in accident sequences. Based on a preliminary analysis, the most significant accident sequences were developed further using event trees. Quantitative frequency estimates for the accident sequences were based on operational data taken from the historical record of the site where the process is performed. Several modeling challenges were encountered in the course of the study. These included linked initiating and accident progression events, fire propagation modeling, accounting for administrative control violations, and handling mission-phase effects.
Finite Element Analysis of Optical Fiber Structures
Authors: Welker B. R. , Uschitsky M. , Suhir E. , Kher S. , Bubel G. 
Published: July 2023

Abstract
Finite element modeling of the state of stress in optical fibers embedded into an epoxy adhesive, which is surrounded by a metal enclosure, is carried out for various geometric configurations with consideration of the local multi-material mismatch effects. The objective of the analysis is to predict the overall response of, and local stress disturbances in, the optical fiber structure subjected to the change in temperature. A new approach to the finite element mesh refinement that enables one to effectively utilize the standard software is suggested. “Global” finite element analysis, including preprocessing homogenization of the fibrous subdomains, was performed assuming that these subdomains can be idealized as unidirectionally oriented composites. It is concluded that multi-scale finite element techniques with the suggested refinement can be used to model thermally induced stresses in heterogeneous optical fiber structures. The obtained results can be helpful when designing these and similar structures characterized by a complicated geometry and a presence of stress concentrators.
Treatment of Benign Prostatic Hyperplasia
Authors: Valvano Jonathan W. , Yuan David Y. , Rudie Eric N. , Clark Steven J. 
Published: July 2023

Abstract
The treatment of benign prostatic hyperplasia (BPH) has implications which affect the majority of the adult male population. Although benign compared to prostate cancer, clinical symptoms can dramatically alter the quality of life. The hyperplastic tissue can cause constriction of the urethra and thus affect voiding of urine. Factors to consider for thermally-based treatments of the prostate include minimization of thermal injury to the urethra and rectum, and maximal delivery of thermal energy to target tissue. Minimizing temperature rise in the urethra allows for minimal or no anesthesia, and has been shown to reduce postoperative complications. Protection of the rectal wall is imperative since injury can lead to clinical complications as severe as a rectal fistula. Due to its location immediately dorsal to the prostate, the ventral aspect of the rectal wall is susceptible to overheating when a uniform radiating microwave heat source is applied transurethrally to treat the prostate.
This paper summarizes the engineering technology. numerical modeling, and clinical results to date.
Forced Convection Heat Transfer in Parallel Channel Array Microchannel Heat Exchanger
Authors: Cuta J. M. , McDonald C. E. , Shekarriz A. 
Published: July 2023

Abstract
An experimental study is underway to investigate heat transfer and pressure drop in a microchannel heat exchanger. Devices with geometry consisting of an array of 54 parallel microchannels with rectangular cross-section, 1.0 mm deep and 0.27 mm wide (aspect ratio approximately 4, with hydraulic diameter 425 mm) have been tested using Refrigerant 124 as the working fluid. Conditions tested include a range of Reynolds numbers between 100 and 570 (where Red is defined using the hydraulic diameter of the channels), uniform heat flux up to approximately 40 W/cm2, and wall surface superheats ranging from approximately 0 to 65 K, in both single-phase and two-phase flow. The average liquid-side heat transfer coefficient showed a significant increase over the expected value in macroscopic flow at the same Reynolds numbers. In the single-phase tests, the Nusselt number values ranged from about 5 to 12 for the conditions tested and varied with Reynolds number, showing increasing Nu with increasing Red. In the two-phase tests, the Nusselt number appeared to be approximately constant with Red, at a value of approximately 20. Exit qualities achieved in the two-phase testing ranged from approximately 4% up to nearly 60%, as determined from an energy balance on the system. These results indicate that substantial improvements in thermal hydraulic performance can be realized in microscale heat exchangers with no significant penalty in the pressure drop.
Large Eddy Simulation of Tube Bundle Geometries Using the Dynamic Subgrid Scale Model
Authors: Barsamian Hagop R. , Hassan Yassin A. 
Published: July 2023

Abstract
The dynamic subgrid scale closure model of Germano et. al (1991) is used in the large eddy simulation computer program, GUST, for incompressible isothermal flows. The advantage of the dynamic subgrid scale model is the exclusion of a model coefficient. This model coefficient is evaluated dynamically at each nodal location for a given timestep by filtering the governing equations on a grid filter and a test filter. A tube bundle geometry of non-staggered arrangement is considered in doubly periodic boundary conditions for two-dimensional simulation. Results of the dynamic subgrid scale simulation are obtained in the form of power spectral densities and flow visualization of turbulent characteristics. Comparisons are performed among the dynamic subgrid scale model, the Smagorinsky eddy viscosity model (Smagorinsky, 1963) using simulations performed with GUST (the Smagorinsky model is used as the base model for the dynamic subgrid scale formulation) and available experimental data. The dynamic subgrid scale model simulations are found to be in good agreement to spectral data available form experiments in similar bundle arrangements. Satisfactory turbulence characteristics are observed through flow visualization of the models. Integral length and time scales are evaluated using correlation curves.
Measurements of Cluster-Wall Contact Times in a Scale-Model Circulating Fluidized Bed
Authors: Noymer Peter D. , Glicksman Leon R. 
Published: July 2023

Abstract
One of the mechanisms of heat transfer at the wall of the riser in a circulating fluidized-bed (CFB) is conduction from the clusters of material moving adjacent to the wall; this mechanism is also called particle convection. Relative to each cluster, particle convection is a transient phenomenon, so that the the amount of time that the clusters spend in contact with the wall influences the rate of heat transfer.
The motion of clusters at the wall has been observed and quantified using thermal imaging as a flow-visualization technique. By heating the clusters at the wall and observing their motion with an infrared camera, the average amount of time that a cluster spends at the wall can be determined. The average contact times measured are between 0.35 s and 0.48 s, and some variation with operating conditions in the CFB is observed. These contact times can also be used to calculate bed-to-wall heat-transfer coefficients around 100 W/m2-K, which is in agreement with other heat-transfer measurements in CFBs. These experiments were conducted in a cold scale-model CFB with a riser that has a 0.159 m square cross-section and is 2.44 m tall.
Laser Ultrasonic Sensing of Penetration Depth in Robotic Welding: Simulated Solidified Welds
Authors: Graham George M. , Ume I. Charles 
Published: July 2023

Abstract
An on-line sensor is required for real-time control of penetration depth in robotic welding. Currently, no on-line techniques exist for direct penetration depth measurement. The development of a penetration control system will significantly reduce the costs associated with repairing or scrapping defective welds. Laser array generated ultrasound is one noncontact, nondestructive method of measuring weld penetration. This paper will discuss the design and implementation of an automated system for on-line weld penetration measurement with a laser fiber bundle array and EMAT (electromagnetic acoustic transducer). Experimental results will be shown for array gain measurements and for penetration measurement in simulated solidified welds.
The Issues in Computer Modeling and Interfaces to Solid Freeform Fabrication
Authors: Dong Jian (John) 
Published: July 2023

Abstract
Solid freeform fabrication (SFF) is an emerging fabrication process for production of physical objects directly from CAD models. Computer modeling and interfaces have not become issues until recent years when the research on the SFF of multiple material components and high precision functional prototypes have been initiated. This paper will summarize a number of these issues and the research directions on these issues will be also discussed.
Towards an Integrated Approach for Analysis and Design of Wafer Slicing by a Wire Saw
Authors: Sahoo R. K. , Prasad V. , Kao I. , Talbott J. , Gupta K. P. 
Published: July 2023

Abstract
Crystalline and polycrystalline ingots of silicon and other materials need to be cut into thin wafers for microelectronics, photovoltaics and many other applications. For slicing process to be cost-effective, the kerf loss should be minimum and the surface finish should be of a high quality. Wire saw can meet these demands and is considered to be a potentially better technology than the inner diameter (ID) saw. An initial study of the current technology shows that the wire saw cutting is a poorly understood process, and no model exists for simulation, design and control of this process. The wire saw slicing process can be well modeled as a cutting process, where the initial fracture occurs because of the stress distribution between the two surfaces subjected to compressive loading and sliding friction. A preliminary analysis is carried out using a standard finite element method to develop a better understanding of this process and determine possible ways of improvements in process design. The results of vibration (modal) and thermal stress analyses show that an accurate prediction of the effects of process parameters would help in improving the wire saw design. Similarly, a proper feed-back control algorithm would enable a better control of the process by using on-line information on wire tension and stiffness, temperature and other relevant quantities. A methodology for systematic approach to analysis and design of an advanced wire saw process is also outlined.
An Automated System for Temperature Dependent Mechanical Property Measurements
Authors: Polsky Yarom , Ume Charles 
Published: July 2023

Abstract
An automated system capable of measuring temperature dependent mechanical properties based on extensional strain has been developed. The system uses either the electrical resistance strain gage technique or a laser extensometer device in conjunction with user programmable thermal cycling, load cycling and data acquisition. An IBM-compatible 486 computer with commercially available software is used to regulate the test cycling and data acquisition. This system is being used to characterize the mechanical properties of printed wiring board (PWB) core materials over manufacturing temperature ranges. This paper will discuss the integration of system components and the system capabilities. Experimental results for 1080 FR-4 Prepreg and copper-foil clad laminate will be presented as well as a comparison of the contact and non-contact methods used for strain measurement.
Three Dimensional Simulation Method for the Analysis of a Ceramic Grinding Process
Authors: Lin I-Chung Joseph , Sathyanarayanan Guruswami , Plebani Louis J. , Buehler William L. 
Published: July 2023

Abstract
A three-dimensional simulation methodology is developed for the kinematic analysis of a ceramic grinding process. The simulation aggregates the results of each grit-workpiece interaction to obtain process output. The simulation combines a three-dimensional wheel topography model obtained from electron microscopic analysis of diamond grinding wheels with a single-grit cutting force model that was constructed from data collected from single-grit cutting experiments. The simulation is used to analyze the influence of processes parameters on process output. The simulated process output is verified with experimental data.
Inverse Method for Estimating Surface Heat Flux Distributions During High Speed Rolling
Authors: Keanini Russell G. 
Published: July 2023

Abstract
This article describes an inverse method for estimating diffusive lime-scale surface heat flux distributions during rolling. Inverse solutions based on remote temperature measurements employ reduced data sets; the diffusive transport time between the roll surface and the embedded measurement array roughly determines the proper sample rate. Following validation, the inverse method is applied to experimental measurements. Validation tests and analysis of experimental data show that the inverse procedure provides accurate surface heal flux estimates over extended time periods (on the order of 3 hours).
A New Rolling Force Modification Equation for the Bland and Ford Cold Rolling Model
Authors: Lin Charlie C. Y. , Atkinson Mark , Cinkowski Charles J. 
Published: July 2023

Abstract
A new rolling force modification equation for the Bland and Ford cold rolling model was derived based on Orowan’s theory and the Huber-Mises yielding criterion of plasticity. The rolling force on each side of the neutral plane was calculated by using a numerical method to integrate the Orowan differential equation. Equations derived by Bland and Ford were used to calculate various parameters contained in the new derived rolling force modification equation. This new equation was used by a computer model to estimate rolling force. A comparison between the estimated rolling force and measured value was made for a wide range of cold-rolled products. A comparison was also made with a rolling force modification equation developed by Hill. The results indicated that the new equation was comparable to the equation derived by Hill for stands with large strip reductions of greater than 2 percent, and it gave significantly better rolling force estimation for stands with small reductions of less than 2 percent where the elastic effect of the strip could be significant.