bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Toughened Composites on the Static Buckling Load and Buckled Position of Composite Laminated Plates
Authors: Jia Hongyu , Rogers Craig A. 
Published: March 2022

Abstract
A nonlinear analysis of the buckling and post-buckling responses of a simply supported laminated composite plate under an axial in-plane compressive load is presented. The model for symmetric cross-ply laminated composite plates made from various composite materials, such as, Graphite/Epoxy, Graphite/PEKK, Graphite/PEEK, and Kevlar/PEKK is given here. The governing equations of post-buckling composite plates with large strains are obtained by using the minimum total potential energy principle. The post-buckling behaviors of Graphite/Epoxy composite plate and toughened composite plates are studied by using this model. The critical buckling load and buckled position are determined. The stress and strain fields of the buckled composite plates are also determined. Buckling analysis is combined with failure analysis by applying Tsai-Hill theory. The effect of the toughened composites (matrix, or fibers or both) on the critical buckling load, post buckling behavior of the laminated composite plates are evaluated.
Vibroacoustic Testing of Linings of Clutches
Authors: Karagulle Hira 
Published: March 2022

Abstract
The density of a clutch lining is an important parameter for its quality. In this work, a nondestructive vibroacoustic test is studied for evaluating the quality of linings. First, the mechanics of the test is studied. The theoretical model shows that the high frequency components of the nondestructive impact force transmitted to the structure decrease if the contact stiffness decreases. The acoustic signals (0–20 kHz) and acousto-ulstrasonic signals (0–40 kHz) are generated by tapping on the linings. 7 linings in good quality with an average density of 1.96 g/cm and 7 linings in bad quality with an average density of 1.65 g/cm3 are considered. The linings are the product of a commercial company. A microphone is used to detect acoustic signals and an acoustic-emission sensor is used to detect the acousto-ultrasonic signals. The signals are captured by a data acquisition card and are analyzed in a personal computer. The spectra of the signals are smoothed by the cepstral analysis. The amplitudes of the smoothed spectra are compared in various frequency bands. The difference in the amplitudes for good and bad quality linings are compared. It is observed that the difference in high frequency components can be used as an indicator of the quality of friction linings.
Fatigue Damage of Glass/Vinyl Ester Thick Composites
Authors: Haque A. , Johnson J. , Vaidya U. K. , Jeelani S. 
Published: March 2022

Abstract
The focus of this study is to investigate the compression-compression fatigue damage of S2-glass/vinyl ester woven composites manufactured through Vacuum Assisted Resin Transfer Molding (VARTM). The compressive behavior and the relevant failure modes of composites are investigated prior to applying the cyclic load. The panels of thicknesses (0.15 in./3.81mm – 0.45 in./11.43 mm) are considered to quantify the process related defect such as void contents and fiber waviness in the thick composite laminates. Void content of each panel is determined through a bum-off test method using a Thermal Gravitational Analyzer (TGA). An optical microscope attached with a grid pattern transparent film is used to measure the waviness parameters of the laminate. The ultrasonic C-scan, A-scan and microscopic examinations are used to identify the manufacturing flaws related to VARTM. The effects of such defects on static compression and compression-compression cyclic behavior of thick composites are investigated. The failure strength, failure strain, modulus and number of cycles to failure at different stress levels for various laminate thicknesses are determined. Weibull plots are generated using both static compression strength and fatigue life cycles. Although the range of the thickness of the laminate was in the ratio of one to three, the variation in compressive strength data was rather nominal. The fatigue performance is observed to improve with the increase in thickness. In-situ monitoring of progressive damage under compressive and cyclic loading is conducted using acoustic emission (AE) method. AE parameters in the form of amplitude, energy and time plots are generated. The compressive and fatigue failure modes are identified by optical and scanning electron microscopic examinations. These failure modes are correlated with acoustic emission Non Destructive Evaluation (NDE) parameters.
Simulation of the Noise Radiated From an Operating Diesel Engine
Authors: Vlahopoulos Nickolas , Kalish Yury , Stark Richard D. 
Published: March 2022

Abstract
Numerical methods can be used to compute the vibration of powertrain systems or components and the corresponding radiated noise. Specifically, the finite element method can be utilized in computing the structural vibration[l-3]. The structural response constitutes the boundary conditions for the acoustic analysis. The boundary element method is utilized in computing the radiated noise[4–6]. In order to achieve reliable noise predictions it is important to have accurate information for the structural vibration since it is the source of the noise. In this work a methodology for applying the loads on the structure is presented. It allows to exert as excitation a combination of measured accelerations, and forces or pressures. It is utilized in simulating the noise radiated from a running engine and determining the effects of design changes. Numerical results for the radiated noise are compared to test data for a baseline design. The effect of two structural design modifications on the radiated noise is computed, and conclusions are deducted.
Flow Noise Source: Resonator Coupling
Authors: Pollack Martin L. 
Published: March 2022

Abstract
This paper investigates the coupling mechanism between flow noise sources and acoustic resonators. Analytical solutions are developed for the classical cases of monopole and dipole types of flow noise sources. The effectiveness of the coupling between the acoustic resonator and the noise source is shown to be dependent on the type of noise source as well as its location on the acoustic pressure mode shape. For a monopole source, the maximum coupling occurs when the noise source is most intense near an acoustic pressure antinode (i.e., location of maximum acoustic pressure). A numerical study with the impedance method demonstrates this effect. A dipole source couples most effectively when located near an acoustic pressure node.
Designing Applications for an OSACA Control
Authors: Sperling Wolfgang , Lutz Peter 
Published: March 2022

Abstract
Within the ESPRIT III project OSACA (Open System Architecture for Controls within Automation systems) of the European Commission the necessary specifications for an open control system were worked out and first prototypes of the system platform were realized. The system platform is the basis of the OSACA architecture and acts as the framework for the integration of application-oriented functionality in a control system.
Several initiatives — under them the German project HÜMNOS — are developing application modules for the OSACA architecture. This paper describes the results that have come out of the OSACA initiative so far, and explains the general structure and design of control applications for the provided framework. Special emphasis is put on the reference architecture which guarantees the interoperability between the single control-specific, vendor-neutral application modules. As illustration, the interaction of an HMI application with OSACA compliant controllers of different vendors is presented.
Intelligent Process Monitoring for Rough Milling Operations Based on Digital Drive Currents and Machine Integrated Sensors
Authors: Kaever Michael , Weck Manfred 
Published: March 2022

Abstract
In Europe a consortium has been formed to develop a Sensor Fused Intelligent Monitoring System for Machining (SIMON). Starting from a generic module structure for process monitoring systems, the system architecture of a fully control integrated monitoring system for rough milling operations is presented based on digital drive signals. Machine integrated sensors are used for calibration and for wear monitoring. The potential of such a system is shown by previous work at WZL. Experimental results demonstrate successful tool overload and tool breakage monitoring for milling and drilling, based on drive current signals. Comprised only of software modules, directly linked into an industrial open system controller, the base system does not need any sensor or signal processing hardware to monitor 06mm drilling or 08mm end milling tools machining steel workpieces. Signal correction has been designed for monitoring during acceleration. Machine integrated sensors are presented to extend the range of reliable monitoring.
Solder Joint Formation Simulation and Component Tombstoning Prediction During Reflow
Authors: Wu Xiaohua , Dou Xinyu , Yeh Chao-pin , Waytt Karl 
Published: March 2022

Abstract
The failure of electrical devices associated with solder joints has become one of the most critical reliability issues for surface-mounted devices. Solder joint reliability performance has been found to be highly dependent on the solder joint configuration, which, in turn, is governed by bond pad size, alloy material, and leadframe structure, as well as solder reflow characteristics. To investigate Tombstone effect causing solder joint failure during leadless component reflow process, this work has focused on 1) developing numerical model for the simulations of the solder joint formation during the reflow process; 2) determining possibility that a tombstone effect for the leadless component may occur by analyzing the force and torque in the problem. Using this methodology, the Tombstone effect associated with different pad geometry configurations has been analyzed though the application of the software tool Surface Evolver. Simulations show that the tombstoning is very sensitive to pad / component geometry design, solder surface tension, paste volume, wetting area and wetting angle. This model simulation can be used to determine optimal solder paste volume, pad geometry configurations and solder material for avoiding Tombstone effect.
Applications of Digital Correlation Method to Microscopic Strain Measurement and Materials’ Property Characterization
Authors: Lu H. 
Published: March 2022

Abstract
The method of digital speckle correlation is introduced, so is the hardware system to implement the method. The advantages and the features of the technique are discussed and application examples are given. Owing to the high spatial resolution that this technique can achieve, the method is especially useful to measure small areas of an object, or a small component in an assembly, whether the surfaces under probing are planar or not. The applications have proved that the technique is a promising tool for the reliability study of microelectronic packages.
An Experimental Investigation on Application of Basic Orthogonal Cutting Model to Ultra-Precision Diamond Cutting
Authors: Okuda Koichi , Hasegawa Motoyoshi , Moriwaki Toshimichi 
Published: March 2022

Abstract
The orthogonal cutting tests were carried out on an ultra precision fly-cutting machine at various depths of cut from 3 μm down to 0.0015 μm (1.5 nm). The cutting force, thickness of chip and contact length between the chip and the rake face of tool were measured in the experiments. The effect of the depth of cut on the cutting force, the shear angle, the tool-chip contact length and the cutting heat were presented and compared with the results of conventional orthogonal cutting process. The compatibility and the limitation of application of basic orthogonal cutting model to ultra-precision cutting was investigated. The experimental data obtained by ultra-precision diamond cutting have a good agreement with the shear angle equations based on basic orthogonal cutting model under the conditions of depth of cut more than 0.2 μm but not at depths of cut smaller than 0.2 μm due to the rounded edge of tool.
Preliminary Results of Laser-Assisted Cleaning of Alumina Coated Carbide Tool Inserts
Authors: Malshe Ajay P. , Khor Kok E. , Bhat Deepak G. 
Published: March 2022

Abstract
This paper describes the results of a preliminary investigation of a novel non-contact surface cleaning method for the reclamation of coated cemented carbide cutting tools. Conventional cleaning processes used for cleaning of cutting tools rely either on aqueous methods which are often not very effective, mechanical methods such as grit blasting which can damage the tool cutting edges, or high-temperature chemical stripping methods which significantly reduce the strength and fracture toughness of the tools. In the present work, cobalt-bonded cemented carbide cutting tool inserts coated with titanium carbonitride (TiCN) and alumina (Al2O3) by CVD process were treated by an excimer laser-based technique to effectively remove partially delaminated or poorly bonded coating layers. The goal was to investigate the feasibility of applying a non-contact technique which is environmentally friendly, and is capable of large-scale application and automation. It is postulated that the process works by explosive and thermal shock which essentially delaminate the coating.
Composite Modeling of Human Cranial Bone
Authors: Hu Hao , Nayfeh Adnan H. , Rosenberg William S. 
Published: March 2022

Abstract
The purpose of this paper was to address an equivalence between a single layer and three layered cranial bone models for intracranial content impact injuries by using composite mechanics approach. A homogenized material model was utilized to model the three layered system of cranial bones as a single layered system. A set of equivalent homogenized material properties can be formulated systematically with confidence. Numerical verifications were carried out by simulating two ball models and a 50th percentile human head model by using finite element approach, which shows that it maximizes modeling and computation economy without sacrificing solution accuracy of variables for evaluating intracranial content injuries. The discrete bone materials were assumed as linear, elastic, and isotropic. So, the resultant equivalent material was anisotropic.
The Recommended Geometry for Laminar Microchannel Heat Sinks
Authors: Lienau Jeffrey J. 
Published: March 2022

Abstract
Rectangular laminar microchannel heat sinks have been used for cooling banks of integrated circuits, semiconductor laser diodes, radar components and optical devices all of which may generate high heat flux. The effect of varying the fin width to channel width ratio and the channel aspect ratio was investigated for silicon heat sinks and the design which provided the minimum base temperature for a given heat transfer rate and given pumping power was recommended. The recommended design had fin width to channel width ratios of 1.3 and 2.4 and channel aspect ratios of 21.2 and 32.8 for water and Fluorinert (FC-5312) coolants respectively. The constant properties, fully developed assumptions were evaluated and were shown to be acceptable for the recommended geometry.
Contact Area and Thermal Contact Resistance in an Ideal Bolted Joint: Part 1 — Study of Contact Area
Authors: Park Chang J. , Kaminski Deborah A. 
Published: March 2022

Abstract
The contact area at the interface of a bolted joint was investigated analytically, experimentally and numerically. Consideration was restricted to an ideal two-plate model for which the interface was perfectly flat. The two plates made circular contact under uniform axisymmetric normal loading. These investigations included the effect of important system parameters such as plate thickness, material properties and loading radius. In the analytical study, a two-plate model with an infinite radius, which had no center (bolt) hole, was mathematically analyzed. The normal stress distribution at the interface was used to predict the contact radius. Two alternative assumptions were considered: 1) continuous contact (no separation) at the interface, 2) discontinuous contact (separation beyond the contact region) at the interface. The continuous model was solved by a Hankel transform and the discontinuous model by a Hankel transform and singular integral formulation.
In the experimental study, a visualization technique using monochromatic light was carried out with a bolted joint which consisted of a transparent polycarbonate plate and a metal plate so that direct calibration of the contact radius was possible. All the test plates had mirror-like surface finishes.
In the numerical study, the finite element method was applied to two different two-plate models: one without a hole and the other with a hole.
The results showed that the discontinuous model produced much closer agreement with the two-plate model with a hole than the continuous model, which produced a large discrepancy. The results also show that the effect of the bolt hole appeared to be insignificant. The physical behavior of the contact radius of a bolted joint can be well explained from the mathematical equation of the discontinuous model. The contact radii obtained from Part 1 were implemented in the study of the thermal contact resistance described in the companion paper.
Characterization of Plastic Packages Using (100) Silicon Stress Test Chips
Authors: Zou Y. , Suhling J. C. , Jaeger R. C. , Lin S. T. , Nguyen L. , Gee S. A. 
Published: March 2022

Abstract
In this work, special (100) test chips containing optimized four element dual polarity rosettes have been applied within several plastic encapsulated electronic packaging configurations. The utilized test chips are capable of evaluating four stress components, and both the in-plane normal stress difference and the in-plane shear stress can be measured in a temperature compensated manner. In this paper, results are reported for test chips encapsulated in 44 pin PLCC packages. The pre and post packaging room temperature resistances of the sensors were recorded. Using the measured resistance changes and the appropriate theoretical equations, the stresses on the surface of the die were then calculated. Also, three-dimensional nonlinear finite element simulations of the plastic encapsulated packages were performed. The experimental results are in reasonable agreement with the finite element predictions, given the limitations of the constitutive models used in the numerical calculations.
Evaluation of Die Stress Using van der Pauw Sensors
Authors: Mian A. K. M. , Suhling J. C. , Jaeger R. C. , Wilamowski B. M. 
Published: March 2022

Abstract
Piezoresistive sensors fabricated on (100) and (111) silicon surfaces are capable of measuring from four to all six stress components on the surface of a die. Such resistor based sensors have been successfully designed and fabricated on these wafer planes, and are being used for measurement of die stresses in electronic packaging. However, the use of resistor sensors has several drawbacks including their large size, low sensitivity, and limited functional temperature range. Van der Pauw (VDP) structures have been identified as one potential sensor candidate for overcoming the limitations of large resistor sensors. In this paper, the feasibility of using van der Pauw structures as stress sensors has been demonstrated. The sensitivity of VDP structures fabricated on both (100) and (111) silicon surfaces to uniaxial stress has been measured using four-point-bending tests, and typical results are presented. The observed VDP stress sensitivities are much higher than those of their analogous resistor sensor counterparts. Preliminary finite difference based anisotropic conduction simulation results are in general agreement with the observed measurements.
Experimental and Numerical Study of Propeller Induced Tunnel Pressures
Authors: Kimball Richard , Choi Jin Keun , Kinnas Spyros A. 
Published: March 2022

Abstract
This paper first describes Phase III of the CAvitating PRopeller Experiment (CAPREX) performed at MIT’s variable pressure water tunnel. The three components of the screen generated nominal wake inflow were measured using an LDV system. The unsteady pressure field on the upper tunnel wall for the first three blade harmonics was also measured in a 5 × 5 grid above the propeller tip, for various propeller cavitation conditions from fully wetted to super-cavitating. Then, a recently developed numerical method which models the flow of a cavitating propeller inside of a tunnel is used for the calculation of the pressures on the tunnel walls. The effects of a time-varying blade cavity source and of the flexibility of the tunnel walls are included in the calculation. Lastly, the predicted pressures are compared directly to those measured in the experiment.
The micrometeorite flux in the Albian–Aptian age (ca. 103–117 Ma): A search for Tycho ejecta in pelagic sediments using chrome spinels
Authors: Martin* Ellinor , Schmitz Birger , Terfelt Fredrik , Aguirre-Palafox Luis Erick , Alvarez Walter 
Published: March 2022

ABSTRACT
Numerical models of meteorite delivery from impacts on the Moon have demonstrated that the impact event forming the lunar crater Tycho (~85 km diameter; ca. 109 Ma age) would have delivered considerable amounts of ejected material to Earth. The ejecta, containing lunar Ti- and V-rich chrome spinels, would have been distributed globally and admixed with seafloor sediments over a few meters of a typical marine stratigraphic interval. In order to locate such ejecta, samples weighing ~12–25 kg each, with one-meter spacing were extracted over an ~30 m interval of the deep-sea formed Calera Limestone, Albian and Aptian age (ca. 103–117 Ma), from the Pacifica Quarry, south of San Francisco. The limestone samples were leached in acids and residues searched for possible lunar Ti-rich chrome-spinel grains.
In a total of 689 kg of limestone, 1154 chrome-spinel grains were found. Of these, 319 contain &gt;0.45 wt% V2O3, of which 227 originate from equilibrated ordinary chondrites. The majority of the other 92 grains with &gt;0.45 wt% V2O3 are most likely from different types of achondritic meteorites. Among these, we found eleven particularly Ti-rich chrome-spinel grains. The elemental abundances of these grains were compared with chrome spinel from lunar, howardite-eucrite-diogenite (HED) and R-chondritic meteorites. This showed that only one of these grains could potentially be of lunar origin. The bulk of the other grains likely originate from HED meteorites based on oxygen isotopic analysis of similar grains in previous studies. Grains with TiO2 &gt;10 wt%, common among lunar spinels are not found, further supporting an HED source for the Ti-rich grains. In summary, Albian and Aptian strata in the Pacifica quarry do not likely record any major lunar impact event. Either the timing of the impact is located within a ca. 110–114 Ma unconformity in the middle part of the section or the impact is likely older than the interval searched.