bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments on the Impact Strength of Microcellular Polycarbonate
Authors: Barlow Chris C. , Kumar Vipin , Weller John E. , Bordia Rajendra K. , Flinn Brian 
Published: January 2022

Abstract
The effects of density and cell size on the impact behavior of microcellular polycarbonate (PC) were investigated. A flexed-beam Izod impact test was conducted and the impact strength was observed to improve over the virgin polycarbonate’s impact strength for foam relative densities of 60% and above. In terms of cell size, the impact strength increased with increasing cell size. The impact strength of these foams appears to be a strong function of both density and cell size.
On the Fluid Dynamics of Adaptive Airfoils
Authors: Jacob J. D. 
Published: January 2022

Abstract
This paper discusses issues and practical requirements for an adaptive wing in relation to currently available technology. Adaptive wings offer many benefits, but a viable wing will require research into several areas, including selection of initial and perturbed airfoil shapes, steady and unsteady aerodynamic analysis of adaptive airfoils, and methods for real-time shape control of an adaptive wing system. An overview of adaptive wing history is briefly covered, including some recent developments. Development considerations for an adaptive wing system are then discussed. Aerodynamic performance and stability should be considered in the context of the wing’s structural integrity and aeroelasticity. Particular attention should be paid to the unsteady nature of the flow, as standard quasi-steady flow analysis techniques should be abandoned due to the rapid changes in wing shape and motion. Due to the large number of variable and measured parameters, an advanced control system is required to relate the flight conditions with changes in geometry. Issues related to adapting wings to various aircraft scales will be discussed, specifically micro aerial vehicles (μAVs). unmanned aerial vehicles (UAVs or RPVs), full-scale aircraft, and ornithopters.
Gun Muzzle Control System Using Barrel Mounted Actuator
Authors: LaVigna Chris , Kwatny Harry , Blankenship Gilmer , Teolis Carole , Mattice Mike , Li Yaowen , Sirkis James 
Published: January 2022

Abstract
The development of an innovative gun pointing control system consisting of a gun barrel mounted high force actuation system, a modal filter sensor system, and a control system for the 30-mm Apache chain gun is described. The actuation system utilizes piezoelectric stack elements arrayed around the barrel to apply large torques directly to the gun barrel for improved control of the gun line of sight (LOS). By exploiting the spatial integrating nature and the coupling of strain to optical propagation in a surface mounted fiber, a barrel mounted optical fiber sensor system is designed which acts as a modal filter. The design, implementation, and testing of a control system for the 30-mm Apache chain gun test bed and the gun barrel mounted actuation system are described. The results of the system testing using gun recoil disturbance simulation and turret slewing inputs show that a significant improvement in gun system LOS error can be achieved.
Shape Control of Deployable Membrane Mirrors
Authors: Martin Jeffrey W. , Main John A. , Nelson George C. 
Published: January 2022

Abstract
Currently the Hubble Space Telescope is able to look further into the universe than was previously possible with conventional earth-based telescopes. Since launching of large telescopes is limited by the weight and size constraints of the shuttle cargo bay, alternate telescope designs must be developed to surpass current capabilities. One possible approach is to form large telescope primary mirrors from membrane materials and provide active control to maintain the proper shape. This paper discusses results from recent research into electron gun shape control of a piezoelectric film bimorph mirror. Observations on the electron energy level/voltage control responses and the glue layer interactions are discussed.
Vulnerability of Embedded Bragg-Grating Sensors to Impact
Authors: Jarlås Rolf , Levin Klas 
Published: January 2022

Abstract
Vulnerability of embedded Bragg grating sensors to impact has been studied in composite laminated plates. The effects of the distance from the supporting boundary and the sensor thickness position were determined. The main objective was to develop an accurate numerical procedure to calculate the local stresses at the sensor from impact in order to determine the criticality with respect to damage initiation. A semi-analytical and a finite element based method were used to consider the contact at impact. From the analysis, it was found that a lower impact energy was required to cause damage in the sensor region when the sensor was embedded close to the boundary. At locations far from boundaries, sensors should not be embedded close to the plate surfaces. For sensors embedded close to a boundary, a thickness position close to the upper surface was found to be less suitable than other positions.
Structural Health Monitoring Using Fiber Optic Sensing
Authors: Ross Paul , Chen Peter , Wagreich Richard , Chen Steve , Sirkis Jim 
Published: January 2022

Abstract
A prototype structural health monitoring system for naval ships based on fiber optic Bragg grating and digital communications has been developed. This is a dual purpose system. Firstly, it is a fiber Bragg grating based multi-position strain sensing network. In addition, its open architecture is designed to allow the same fiber network to be used as an optical data bus to carry digitized signals from an array of existing devices on naval platforms (e.g. communications, fire control, surveillance, resistance strain data, etc.). The open architecture system was demonstrated by measuring the structural response of 6 foot steel beam instrumented with temperature compensated fiber Bragg grating strain sensors at 2 Hz excitation frequency to simulate primary hull bending modes. Using a hybrid wavelength and spatial division multiplexing technique, the fiber Bragg grating sensor signals were multiplexed with analog signals from resistance foil strain gages also located on the beam, and transmitted via a fiber optic data bus to a remote receiver and control computer for real time data logging and analysis. Environmental static loading tests show that fiber optic technology can provide significant improvements in accuracy, repeatability, and reliability over existing resistance foil strain gage technology under extreme humidity and temperature, characteristic of marine environments.
Design of Extruded Aluminum Space Frame Front End Structures for Crash Energy Management: Part II
Authors: Baccouche Mohamed Ridha , Mahmood Hikmat F. 
Published: January 2022

Abstract
This paper presents the second part of a two-part design and analysis work for crash energy management that was conducted two years ago. Part I has been presented at the 1997 ASME crashworthiness conference held in Dallas, Texas and published in the ASME proceedings AMD-Vol.225 (BED-Vol.38).
The present paper briefly reviews the components testing results and presents a detailed discussion of the CAE modeling and models results for the full front end structure of an extruded aluminum space frame. The front end structure consists mainly of a bumper, cross member, radiator support, front and backup lower rails, upper rails, shock tower support, subframe and attachments. The materials used are aluminum alloys series 5xxx and 6xxx. The 5xxx series aluminum was used only as reinforcement. The 6xxx aluminum was used as primary material for the various components as well as for reinforcing the backup lower rails.
Force-deformation response, energy absorbed during the crash event, stress distribution and failure sequences for the front end structure have been generated and plotted. A detailed discussion of the peak and mean crush load from the force-deformation response, the energy absorbing capability of the structure from the energy-deformation curve, the axial and bending stress distribution, and the order of sequence of collapse is presented in this paper. A summary list of recommendations and critical design issues is also given at the end of this paper.
Design Depowered Airbag Mass Flow Rate by Using Occupant Simulation Models and Neural Network
Authors: Liu D. S. , Chang S. Y. 
Published: January 2022

Abstract
This study presents to use occupant sled test simulation model in conjunction with neural network to identify proper mass flow rate for De-power airbag. Finite element models included Hybrid III crash dummy, airbag and sled buck are employed to simulate sled test. The crash pulse and the HIC number and its duration times output from full car crash test is used to calibrate this base line numerical model. Neural network model with backpropagation learning algorithm is then built. A set of candidate mass flow rate and associated dummy HIC values, chest G value output from simulation model are designated as the training pairs to adjust the weights of the neural network. Once the training complete, the target dummy HIC values, one for 50 % tile normal position, the other for 5% tile out of position, are given and input into the neural network to predict the approximated mass flow rate. Numerical examples were studied to demonstrate the feasibility of the proposed method.
ISP: An Airbag Inflator Simulation Program
Authors: Kang Jian , Wang J. T. 
Published: January 2022

Abstract
An inflator simulation computer program, ISP, has been developed to facilitate the assessment of transient heat transfer models. In addition to providing for incorporation of new transient heat transfer models, this program has several other useful and unique features: 1) it allows gas to have multiple chemical components, 2) it allows gas to use temperature-dependent thermodynamic properties, 3) it can self-generate gas thermodynamic properties through linkage to a chemical kinetic package CHEMKIN, and 4) it allows the users to use either cubic spline or polynomial curve fitting to smooth the noise tank test data. This program can simulate three basic tasks: inflator tank test analysis using either the average temperature method or the dual pressure method, tank test simulation, and bag deployment analysis.
A Review of Mathematical Models for Rollover Simulations
Authors: Chou C. C. , Wu F. , Gu L. , Wu S. R. 
Published: January 2022

Abstract
A review of mathematical models simulating rollover events under various test conditions is presented. The types of models reviewed include rigid-body-based and finite-element-based models. Simulations of FMVSS 208 rollover test procedure using a rigid-body-based model is demonstrated. Model limitations and issues are addressed to potential users/modelers regarding their applicability. Areas of further improvements over these models are also presented.
Time-of-Flight vs. Phase Contrast Techniques for MRI Velocimetry
Authors: Kutter Ella C. , Moser Kevin W. , Georgiadis John G. , Morris H. Douglas , Buckius Richard O. 
Published: January 2022

Abstract
Magnetic Resonance Imaging (MRI) is a non-invasive versatile tool for achieving full-field quantitative visualization. The MRI signal is a result of the interaction between radiofrequency (RF) pulses with nuclear spins exposed to a strong static magnetic field. The two main classes of techniques for MRI velocimetry are: spin-tagging techniques and phase contrast techniques. Spin-tagging techniques involve tagging and tracking a material volume of fluid. This allows a time-of-flight approach to the estimation of local velocity. Phase contrast is based on the difference in accumulated phase (time integral of angular frequency) in the signal arriving in the detector from moving and stationary spins exposed to magnetic field gradients. We compared velocity measurements with spin-tagging and phase contrast by probing the pressure-driven flow of water in a straight tube (Poiseuille flow). Profiles of the axial velocity along various cross sections were acquired for steady laminar flow with Reynolds numbers 170, 670, and 1000. Depending on the imaging sequence and Reynolds number, the velocity errors fell in the 0.5%–3.2 % range.
A Domain Decomposition Algorithm for Thermal Analysis in X-Ray Lithography With Cylindrical Geometry
Authors: Dai Weizhong , Nassar Raja 
Published: January 2022

Abstract
X-ray lithography is an important technique in micro fabrication used to obtain structures and devices with a high aspect ratio. The process is composed of a mask and a photoresist deposited on a substrate (with a gap between mask and resist). Predictions of the temperature distribution in the different layers (mask, gap, photoresist and substrate) and of the potential temperature rise are essential for determining the effect of high flux x-ray exposure on distortions in the photoresist due to thermal expansion. In this study, we develop a three-dimensional numerical method for obtaining the temperature profile in an x-ray irradiation process by using a hybrid finite element-finite difference scheme for solving three-dimensional parabolic equations on thin layers with a cylindrical geometry. A domain decomposition algorithm is then obtained based on a parallel Gaussian elimination for solving block tridiagonal linear systems. Numerical results show the method to be efficient.
Particulate Behavior in Micromanifolds
Authors: Valentin Gregory E. 
Published: January 2022

Abstract
The primary objective of this project was to design and test a manifold that would allow Beckman to measure the fluorescence of micron-size spheres. Specifically, Beckman should be able to measure the intensity and frequency of the spectra for each sphere without interference from the another sphere. The design must also allow Beckman to measure a representative sample of the beads, over 75% of those originally introduced. Second, the optical measurements should yield a high signal to background ratio, near 100:1.
Six potential designs were modeled using ADINA-F, a computational fluid dynamics (CFD) software package. The computer simulations of these six systems produced favorable results and six micromanifolds were manufactured and tested. Micromanifold experiment results have been analyzed to determine their effectiveness of meeting Beckman’s objectives and compared with CFD analysis to evaluate computer model results.
The Development of Reconfigurable Cellular Machines
Authors: Umeda Yasushi , Kondoh Shinsuke , Sato Roberto Kiyoshi , Sakao Tomohiko , Tomiyama Tetsuo 
Published: January 2022

Abstract
While present highly-developed mechatronics machines have many advantages, they also have problems, such as, fragility to minor faults and inflexibility to changes of the environment and user needs. In order to solve these problems, it is the key to make a product reconfigurable. Here, reconfigurability of a machine is the ability to change its functions, behaviors, and/or structure flexibly according to external and internal changes. This paper clarifies indispensable features of reconfigurable machines and proposes cellular machines as one of the most appropriate machine architecture for the reconfigurable machines. A cellular machine consists of distributed autonomous intelligent units (called “cells”). This paper also demonstrates that the cellular machines have structural reconfigurability, fault-tolerance, and functional reconfigurability which are indispensable features of reconfigurable machines.
Monitoring of Localized Gear Faults by Linear Dynamic Modeling
Authors: Li C. James , Limmer J. D. 
Published: January 2022

Abstract
This paper describes a method that utilizes linear dynamic modeling to track the development of localized gear faults such as fatigue cracks. A model is created from the gear meshing vibration signal when the gear is new and then the model is applied to vibration data taken over the gear’s lifetime to calculate the prediction error. This error is expected to increase over the gear’s lifetime as the “evolution” of the faults alters meshing stiffness. The method is evaluated by experimental data collected in a test where gear tooth fatigue cracks grew over time. It was found that the method gave more consistent trend when compared with state-of-the-art techniques.
Analytical Stability Prediction and Design of Variable Pitch Cutters
Authors: Altintas Yusuf , Engin Serafettin , Budak Erhan 
Published: January 2022

Abstract
An analytical prediction of stability lobes for milling cutters with variable pitch angles is presented. The method requires cutting constants, number of teeth, and transfer function of cutter mounted on the machine tool as inputs to a chatter stability expression. The stability is formulated by transforming time varying directional cutting constants into time invariant constants. Constant regenerative time delay in uniform cutters is transformed into non-uniform multiple regenerative time delay for variable pitch cutters. The chatter free axial depth of cut is solved from the eigenvalues of stability expression, whereas the spindle speed is identified from regenerative phase delays. The proposed technique has been verified with extensive cutting tests and time domain simulations. The practical use of the analytical solution is demonstrated by an optimal tooth spacing design application which increases the chatter free depth of cuts significantly.
Contact Mechanics of Superfinishing
Authors: Chang Shih-Hsiang , Farris Thomas N. , Chandrasekar Srinivasan 
Published: January 2022

Abstract
Superfinishing is an abrasive finishing process in which a smooth work surface is produced by simultaneously loading a bonded abrasive stone against a rotating workpiece surface and oscillating (reciprocating) the stone at high frequencies. The surface topography of a 600 grit aluminum oxide stone used for superfinishing is quantitatively described using scanning phase-shift interferometry. A bounded three-parameter lognormal distribution is found to provide a more accurate representation of cutting edge height distribution than a bounded normal distribution, especially in fitting the upper tail end of data. Moreover, the stone surface characteristics are nearly constant throughout stone life suggesting that superfinishing is a self-dressing process. This stone surface geometry is used to develop a contact mechanics model of the superfinishing process. The model estimates the number of cutting edges involved in material removal, the load distribution on these edges, and the resulting surface roughness of the super-finished surface. The effect of contact pressure on these estimated values has been studied. Only a very small percentage (less than 0.16%) of the cutting edges, which are comprised of the large cutting edges occurring in the tail end of distribution, are actively engaged in material removal. Further, the arithmetic average surface roughness, Ra, is found to be related to the average depth of penetration while the peak-to-valley surface roughness, Rt or Rtm, is related to the maximum depth of penetration. The prediction of surface roughness of this model is found to agree very well with experimental results for superfinishing of hardened steel surfaces.
Resistance Spot Welding: A Neural Network Approach to Modeling
Authors: Shriver Justin , Hu S. Jack , Peng Huei 
Published: January 2022

Abstract
This paper discusses recent progress in the development of a feedback controller for the resistance spot welding (RSW) process. Two key elements of our control architecture will be operating condition detection and nugget growth estimation. In this paper the operating condition problem is addressed with respect to five well-defined faults. We employ a novel neural network approach in the design of the operating condition detector. The nugget growth estimation problem is addressed by employing a recurrent neural network model of the process, for which preliminary results are shown.
Experimental Evaluation of the Laser Assisted Machining of Silicon Nitride Ceramics
Authors: Rozzi Jay C. , Pfefferkorn Frank E. , Incropera Frank P. , Shin Yung C. 
Published: January 2022

Abstract
Laser assisted machining (LAM), in which a workpiece is locally heated by an intense laser source prior to material removal, provides an alternative machining process with the potential to yield higher material removal rates and lower manufacturing costs for difficult-to-machine materials such as structural ceramics. To assess the feasibility of the LAM process, experiments were performed on silicon nitride workpieces for a wide range of operating conditions. Data for cutting forces and surface temperatures indicate that the lower bound of the material removal temperature for avoidance of cutting tool and/or workpiece fracture corresponds to the YSiAlON glass transition temperature (920–970°C). As temperatures near the cutting tool increase to values above the glass transition temperature, the glassy phase softens, facilitating plastic deformation and, correspondingly, the production of semi-continuous or continuous chips. The silicon nitride machined workpiece surface roughness (Ra = 0.39 μm) for LAM at the nominal operating condition was nearly equivalent to a value associated with the grinding of silicon nitride using a diamond wheel (Ra = 0.2 μm). Examination of the machined surfaces and chips reveals no detectable sub-surface cracking or significant changes in microstructure, respectively. Relative to grinding, the most significant advantage of LAM is its ability to achieve much larger material removal rates with high workpiece surface quality and reasonable levels of tool wear.
A New Model and Analysis of Orthogonal Machining With an Edge Radiused Tool
Authors: Manjunathaiah Jairam , Endres William J. 
Published: January 2022

Abstract
A new machining process model that explicitly includes the effects of the edge hone is presented. A force balance is conducted on the lower boundary of the deformation zone leading to a machining force model. The machining force components are an explicit function of the edge radius and shear angle. An increase in edge radius leads to not only increased ploughing forces but also an increase in the chip formation forces due to an average rake angle effect. Previous attempts at assessing the ploughing components as the force intercept at zero uncut chip thickness, which attribute to the ploughing mechanism all the changes in forces that occur with changes in edge radius, are seen to be erroneous in view of this model. Calculation of shear stress on the lower boundary of the deformation zone using the new machining force model indicates that the apparent size effect is mainly due to deformation below the tool (ploughing) and a larger chip formation component due to a lower shear angle. The shear strain rate is substantially higher at smaller uncut chip thickness resulting in a mild effect of strain-rate hardening. Frictional conditions do not exhibit change with uncut chip thickness if an average rake formulation is used.
Assure the Matchable Degree in Selective Assembly via PCI-Based Tolerance
Authors: Zhang Yu , Fang X. Daniel 
Published: January 2022

Abstract
Selective assembly is a method to achieve high precision fit using low precision parts. The current practices in selective assembly lack a physical process model to guide the design and process of mating parts, consequently, selective assembly is often a nightmare for manufacturing people. Process capability indices (PCIs) are the widely accepted process parameters, functioning as a measure of process performance. In this paper, the concept of PCI-based tolerance is proposed as an interface between quality requirements and statistical process control (SPC) parameters. An analytical model involving PCI-based tolerance is developed to predict and assure the matchable degree in selective assembly. As matchable degree and other process quality requirements can be assured at the stage of design by introducing PCI-based tolerance, the process of selective assembly can be improved significantly as an effective way to achieve precision assembly with economical manufacturing processes.