bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Analysis of Quality Control Methods for Intelligent Processing of Polymeric Materials
Authors: Kazmer David O. , Petrova Tatiana 
Published: March 2022

Abstract
Global manufacturers of thermoplastic molded parts increasingly require 100% quality inspection levels that are difficult to achieve. While process complexity makes it difficult to attain the desired part properties during start-up. the stochastic nature of the process causes difficulty in maintaining part quality during production. This paper formally compares several alternative quality control methods that are currently utilized for processing of polymeric materials. To identify the technical issues associated with this goal, the injection molding process is described utilizing a control systems approach. Afterwards, four different methods of quality regulation are synthesized for injection molding: open loop quality control, statistical process control, trained parameter control, and on-line quality regression. For each strategy, the level of quality observability and controllability are determined against the dynamics of the manufacturing system.
The results indicate that none of the quality regulation strategies have the underlying design architecture to deliver 100% quality assurance across a diverse set of application characteristics (quality requirements, material properties, mold geometries, and machine dynamics). As such, subsequent discussion focuses on defining the system requirements for achieving ‘intelligent’ processing of polymeric materials that are needed by industry.
Finite Element Prediction of Sink Marks in Injection Molded Plastic Parts
Authors: Battey David J. , Gupta Mahesh 
Published: March 2022

Abstract
A numerical procedure to simulate the formation of a sink mark near the base of a rib in an injection molded plastic part has been presented. Two commercially available software packages, C-Mold and Abaqus, have been used to predict sink marks. Dependence of sink mark depth on various geometric and molding parameters has been analyzed. The predicted sink mark depth is found to be in good agreement with experimental results from the literature.
3-D Numerical Simulation of Blow Moulding Technology Involving Sequential Coextrusion
Authors: Debbaut Benoît 
Published: March 2022

Abstract
A 3-D numerical simulation is presented for typical applications in blow moulding involving sequential coextrusion. This technology is applied for the production of automotive boots and opaque containers or bottles with a window stripe. A fluid membrane element is developed and presented for the blow moulding simulation of geometrically complex objects. A Lagrangian formulation is used for the motion governing equations. The numerical tool is applied for predicting the material behaviour in the production of an automotive boot and of a soap bottle with a window stripe. The contact between parison and mould is handled by a robust algorithm. Next to the description of the parison deformation, we concentrate on the prediction of wall thickness, both axial and circumferential extension components and the area stretch ratio as well.
Automating the Design Process and Powder Processing of Functionally Gradient Materials
Authors: Kwon Patrick , Crimp Melissa , Chung Moon Jung 
Published: March 2022

Abstract
There is great deal of interest in Functionally Gradient Materials (FGMs) as evidenced by three recent international conferences on the subject (Yamanouchi, et al., 1990, Holt, et al., 1993 and Ishner and Cherradi, 1994). Similar to composites, FGMs are microscopically inhomogeneous. However, unlike most composites, macroscopic inhomogeneities are designed into FGMs. This is achieved by continuously varying the volume fraction of the second phase in a controlled manner. Thus, the distribution of the second phase has ‘to be designed’ based on the type of application and geometry of the structure. In addition, their inhomogeneous nature causes non-uniform shrinkage and cracks during processing before FGMs are ever put into service. Accordingly, two independent research programs are in progress on FGMs at Michigan State University; (1) fabrication technology and (2) design process management tools. On the former program, powder fabrication protocols are being developed to reduce processing-induced residual stresses. On the latter program, in a benchmark study for the framework developed by Baldwin and Chung (1995), the complete design process for axisymmetric FGMs cylinders is implemented.
A Damage Mechanics Based Approach to Durability Assessment of Composite Materials
Authors: Talreja Ramesh 
Published: March 2022

Abstract
The conventional way of durability assessment, based on experience with metals and still common in industry, is by fatigue life (S-N) curves, strength degradation curves, creep curves, etc., all of which are empirical and require extensive testing in every case. For composite materials, the cost associated with this approach is high because of the numerous parameters of consituent properties, geometry and architecture involved. Alternative approach is to characterize and analyze damage and its evolution, all of which belong to the field of damage mechanics. This paper will review this approach and the progress made to date, and project what lies ahead.
Ceramic Composites Technology Development for Industrial Applications at Babcock & Wilcox
Authors: Goettler Richard W. , Keeley Joseph T. , Wagner Richard A. 
Published: March 2022

Abstract
Babcock & Wilcox (B&W) and its parent corporation, McDermott International, Inc., comprise one of the world’s largest energy engineering and service companies. Included within the spectrum of it’s businesses are:
• fossil power generation systems, related environmental equipment and boiler cleaning products
• design engineering, structure fabrication, and equipment for offshore oil and gas production
• nuclear fuel and other nuclear propulsion components for the US Navy
• industrial heat exchangers and condensers
• automated work cells for material processing and inspection
• design of onshore hydrocarbon processing facilities
• environmental remediation services
Process Zone of Polycrystalline Alumina
Authors: Tran D. K. , Kobayashi A. S. , White K. W. 
Published: March 2022

Abstract
A number of papers, which were published during the past fifteen years, have attributed the small KIC in ceramics to the frontal and trailing fracture process zones (FPZ) associated with the crack tip. The toughness due to these two FPZ’s have been refereed to as the intrinsic and extrinsic toughness, respectively (Ritchie, 1997). Theoretical papers on the frontal FPZ considered only the crack tip shielding effect by the microvoids and did not estimate the dissipated energy by the generation and coalescence of these microvoids. Also earlier theoretical and experimental papers on the trailing FPZ considered only the crack bridging effect due to the fiber in a ceramic composite and its influence on the fracture toughness with the exception of Guo et. al. (1997) who used a hybrid experimental-numerical technique to estimate the dissipated energy in an alumina double cantilever beam (DCB) specimen. The objective of this paper is to present further results on the extrinsic fracture energy dissipated in a high density polycrystalline alumina.
Damage in Ceramic Matrix Composites With Arbitrary Microstructures
Authors: Bulsara V. N. , Talreja R. , Qu J. 
Published: March 2022

Abstract
It has been well-recognized that the fiber spatial distribution in a continuous fiber-reinforced (CFR) composite has a significant effect on the transverse behavior of the composite. In this study, quantitative microscopy in conjunction with finite element analysis are used to study the effects of fiber distribution on damage initiation in a unidirectional composite under a uniaxial loading transverse to the fibers.
Prediction of First Ply Failure in Scaled Cross-Ply Composite Laminates
Authors: Jackson Karen E. 
Published: March 2022

Abstract
Previous research on scaling effects in composite materials has demonstrated that the stress levels at first ply failure and ultimate failure of composite laminates are dependent on the size of the laminate. In particular, the thickness dimension has been shown to be the most influential parameter in strength scaling of composite coupons loaded in tension. Geometrically and constitutively scaled laminates exhibit decreasing strength with increasing specimen size, and the magnitude of the strength-size effect is a function of both material properties and laminate stacking sequence. Some of the commonly used failure criteria for composite materials such as maximum stress, maximum strain, and tensor polynomial (e.g., Tsai-Wu) cannot account for the strength-size effect In this paper, three concepts are developed and evaluated for incorporating size dependency into failure criteria for composite materials. An experimental program of limited scope was performed to determine the first ply failure stress in scaled cross-ply laminates loaded in tension. Test specimens were fabricated from AS4/3502 graphite-epoxy composite material with laminate stacking sequences of [0°n/90°n/0°n]T where n = 1–6. Two experimental techniques were used to determine first ply failure, defined as a transverse matrix crack in the 90° ply: (1) step loading with dye penetrant x-ray of the specimen at each load interval, and (2) acoustic emission. The best correlation between first ply failure analysis and experimental data was obtained using a modified Weibull approach which incorporated the residual thermal stress and the outer ply constraint, as well as the ply thickness effect A second set of experiments was performed to determine the tensile response and ultimate failure of the scaled cross-ply laminates. The results of these experiments indicated no influence of specimen size on tensile response or ultimate strength.
Measurement of Single Burning Coal Particles in Swirl-Stabilised Flames
Authors: Prassas Ilias , Taylor A. M. K. P. , Whitelaw J. H. 
Published: March 2022

Abstract
We report on the application of a combined shadow Doppler velocimeter and two-colour pyrometer instrument to make simultaneous measurements of the velocity, size and temperature of single coal particles in the near-burner region of 10 kW swirl-stabilised, natural-gas supported pulverised-coal flames with gas equivalence ratio of 0.69. Shadow Doppler velocimetry is an imaging technique for the simultaneous measurement of the velocity and the area of the projected image of an irregular particle illuminated by the laser beams of a conventional laser Doppler velocimeter (LDV), whilst the two-colour pyrometer was operating at wavelengths in the visible range, namely at 514.5 and 632.8 nm. Profiles of the fraction of burning particles and distributions of the size and velocity of the burning particles and the ensemble, which consisted of both burning and non-burning particles, were constructed from the raw data. In addition, an amplitude-based discrimination criterion was applied to the pyrometer measurements to produce temperature distributions of those measurements which corresponded to burning char as opposed to those corresponding to volatile flames surrounding particles. Increase of the swirl number from S = 0.41 to S = 0.57 resulted in penetration by the primary air jet of the recirculation zone on the centreline, 50% lower gas temperatures compared with S = 0.41 and accordingly, less than 5% burning particles for S = 0.57 in contrast to the 85% for S = 0.41 at the same location. For S = 0.41, except from locations near the centreline, where only particles with reverse velocities and size smaller than 60 μm were burning, only minor differences were found in the size-, velocity - distributions between burning particles and the ensemble. Despite the higher particle temperatures on the centreline, the relatively high particle burning fraction close to the oxygen-rich shear layer implies that those particles are more likely to yield NOx emissions from fuel-bound nitrogen.
Study on a Thermal Boundary Layer of Drag Reducing Surfactant Solution: Measurements of Temperature Fluctuation
Authors: Kawaguchi Y. , Daisaka H. , Li P. W. , Yabe A. , Hishida K. , Maeda M. 
Published: March 2022

Abstract
In order to clarify the mechanism of turbulent heat transfer in drag reducing flow by surfactant additives, temperature in thermal boundary layer in two dimensional channel has been experimentally investigated. Time mean temperature and temperature fluctuation were examined at the Reynolds number of 1.2 × 104 using a tine wire thermocouple probe. The surfactant system tested was CTAC/NaSal/water.
A high diffusivity layer near the wall was found in the thermal boundary layer of surfactant solution. The layer is formed by micellar phase change. Time scales of the temperature fluctuation in surfactant solution flow became large compared to the water flow. It suggests the role of the fluid elasticity to suppress the coherent structure near the wall. As the drag reducing additives have a direct effect on the flow structure in the buffer layer at 10 &lt; y+ &lt; 100, reductions of drag and heat transfer are not recovered nevertheless of high diffusivity layer.
Nonisothermal Multiphase Subsurface Transport on Parallel Computers
Authors: Martinez M. J. , Hopkins P. L. , Shadid J. N. 
Published: March 2022

Abstract
We present a numerical method for nonisothermal, multiphase subsurface transport in heterogeneous porous media. The mathematical model considers nonisothermal two-phase (liquid/gas) flow, including capillary pressure effects, binary diffusion in the gas phase, conductive, latent, and sensible heat transport. The Galerkin finite element method is used for spatial discretization, and temporal integration is accomplished via a predictor/corrector scheme. Message-passing and domain decomposition techniques are used for implementing a scalable algorithm for distributed memory parallel computers. An illustrative application is shown to demonstrate capabilities and performance.
An Exercise in Parallelizing a Legacy Code
Authors: Freitas Christopher J. 
Published: March 2022

Abstract
Parallel computing methods were used to transform a serial computer code to take advantage of the computational power of clusters of workstations and multiprocessor computers. The goal of this effort was to increase the computational speed of an existing or legacy code such that multiple simulations could be performed in a day, rather than requiring days to complete a single simulation. Further, this improvement in computational performance was to be completed quickly; i.e., in a few weeks, and was to maintain solution accuracy as established by simulation benchmarks performed with the original code. The approach taken to achieve this goal is likely typical of what others working in industrial environments may be required to do when attempting to address the issue of transitioning from serial computing environments to one based on a parallel architecture. The essential elements to recasting a serial code into a parallel code are discussed.
Design Considerations in Avionics Electronic Packaging
Authors: Jamnia Ali , Walter Robert E. 
Published: March 2022

Abstract
In designing avionics electronics packages, four areas of engineering need to come together and work concurrently as a team. These are electronic, electro-mechanical packaging, thermal and finally vibration engineers. Often times, thermal and vibration analyses are done only as an afterthought through experimental means to ensure Federal Aviation Authority (FAA) Federal Aeronautics Regulations (FAR) and / or ARINC standards.
In this paper, the mechanics and thermal design procedure and calculations (based on both analytical means and finite element methods) of an airborne ARINC 746 Cabin Telecommunications Unit (CTU) are discussed along with the relevant FAR’s, as well as, ARINC standards are considered. Finally, reliability and failure rates of components and their effects on the performance of the system are studied.
Manufacturability of Underfill Processing for Low Cost Flip Chip
Authors: Baldwin Daniel F. , Pascarella Nathan W. 
Published: March 2022

Abstract
Advanced electronics assembly based on direct attachment of semiconductor devices to printed circuit boards is a rapidly growing technology. Direct chip attach (DCA) or flip chip on board (FCOB) processing typically requires application of underfill materials in order to achieve adequate reliability for commercial electronic applications. Unfortunately, flip chip on board processing has yet to become a low cost, high throughput process compatible with high volume surface mount processing. In order for FCOB processing to be SMT compatible, innovative techniques for underfill processing are required. This paper analyzes underfill processing in order to assess manufacturablity in terms of productivity and cost. In particular, four techniques for underfill processing are analyzed including capillary flow, vacuum assisted capillary flow, injection flow, and compression flow processing.
Moisture Diffusion in Epoxy Molding Compounds Filled With Silica Particles
Authors: Uschitsky M. , Suhir E. 
Published: March 2022

Abstract
Mechanical reliability of epoxy molding compounds in plastic packages of integrated circuits (IC) devices is affected to a great extent by the materials ability to absorb moisture. Accordingly, the objective of the study is to evaluate the effect of moisture sorption on the mechanical properties of the compounds. The diffusion of water in compounds filled with silica and alumina nitride particles has been studied experimentally for systems with moderate and high concentration of fillers. The analysis of the weight gain profiles has shown that the process of moisture diffusion is non-Fickian and that the moisture weight gain depends on the specimen’s relative humidity and the concentration of fillers. As to the hygro-thermal (swelling) stress, caused by moisture diffusion, we found that this stress is very low (its average value does not exceed 662 psi). We showed also that moisture diffusion leads to an appreciable decrease in the compound’s strength and to a substantial increase in the material’s plasticity. The obtained results can be helpful in the analysis of the mechanical behavior of epoxy molding compounds used in electronic packaging.
Thermoelastic Behavior of Filled Molding Compounds: Composite Mechanics Approach
Authors: Uschitsky M. , Suhir E. , Kammlott G. W. 
Published: March 2022

Abstract
Reliability of epoxy molding compounds used in plastic packages of integrated circuit (IC) devices depends on the level of thermal stresses caused by the thermal expansion (contraction) mismatch of the epoxy and the silicon materials. In this analysis we asses the effect of silica fillers on the thermal stresses. We conclude that thermal stresses in the epoxy molding compound (composite) can be indeed reduced by the application of appropriate fillers. We found, however, that the volume concentration of the fillers, does not have to be larger than 0.3 to keep the thermal stresses at a sufficiently low level. This number is close to the fillers volume concentration (c = 0.336–0.390) in actual commercially available molding compounds. The obtained results and recommendations can be helpful in the analysis of stresses and physical design of plastic packages of IC devices.
Numerical Computation of the Heat Transfer to a Spherical-Tip Anode During an Electronic Flame Off Process
Authors: Sripada Srinivas S. , Ayyaswamy P. S. , Cohen I. M. 
Published: March 2022

Abstract
In the ball-wedge bonding process employed in microelectronic packaging, the first step is the formation of a spherical tip by the melting and roll-up of a segment of a cylindrical wire. The heat transfer for the melting and roll-up to a spherical-tip shape is provided by a plasma are that is struck between the wire tip (anode) and a flat plate cathode (wand). Eventually, the spherical tip becomes part of a ball. The ball so formed is bonded on the bond pad of a chip, and the unmelted segment of the wire is looped to form a second (wedge) bond on the lead frame. This provides the interconnection between the chip and the external world. The plasma arc provides heat energy to the wire causing it to melt. A portion of the energy generated by the arc is lost by conduction up the wire, while another portion is lost to the surroundings by radiation and convection. A portion is also lost to the cathode plate. In order to estimate the various heat transport quantities, a numerical simulation of the plasma arc process is required. Here, we provide results of such a numerical simulation. A set of continuum conservation equations for the charged particle densities and the temperatures in the discharge gap are solved, along with Poisson’s equation for the self-consistent electric potential. The equipotential contours, the electron number density and temperature variation in the discharge gap, and the results for the heat transfer to the spherical tip of the wire are presented. Once the heat transfer is evaluated in this manner, subsequent calculations for melting and the ultimate shape and size of the ball may be made. These calculations in turn may be used to develop optimal characteristics for bonding which consist of near-spherical balls with minimal porosity. These are known to be the best candidates for a secure interconnection between the chip and the lead-frame. Although in the past we have published many results for related situations, this is the first time when the anode geometry is completely taken into account. The numerical calculations involve adaptive grid generation based on a body-fitted coordinate system. Results provided here are of immediate application value to the microelectronic packaging industry.
Effects of Eccentricity on Glass Temperatures in the Neck-Down Stage of the Optical Fiber Drawing Process
Authors: Dogu Yahya , Kaminski Deborah A. 
Published: March 2022

Abstract
A three-dimensional model of the neck-down stage of an optical fiber draw furnace was formulated to examine the effects of eccentricity on preform temperature and flow in the furnace. Eccentricity is an unavoidable off-manufacturing condition, which is the deviation between the centers of the cylindrical furnace and the glass preform rod. The Navier-Stokes and energy equations describing the momentum and thermal transfers in the draw furnace were solved simultaneously both in the glass and gas domains using the finite element method. Temperature dependent physical properties were considered. Radiation heat transfer was added into the model as surface-to-surface radiation between the glass surface and furnace wall, using a full enclosure analysis. Radiation inside the glass was approximated by using the Rosseland diffusion approximation.
The circumferential temperature distribution and viscosity change on the preform surface were determined. They increase with the eccentricity ratio. The eccentricity is the distance between the furnace axis and the preform axis. The gas flow is unsymmetrical due to eccentricity. Most of the temperature gradients and viscosity changes were not large within the furnace due to eccentricity. A balanced temperature field in the furnace is due to the high radiation heat transfer. Since the preform necks down within the furnace and becomes thinner in the lower half, the glass becomes more isothermal due to its high radiation coupled glass conductivity. However, although the resulting temperature difference on the glass preform is small, the gradient is high. This temperature gradient becomes important when the exponential temperature dependence of the glass viscosity is considered. The resulting viscosity difference in the neck-down region will cause the glass to flow faster on one side than on the other side resulting in nonuniform consumption of the glass preform. Thus, the desired symmetric root shape of the glass preform may change.