bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization Switching for Ferroelectric Materials
Authors: Park S. B. , Park S. S. , Carman G. P. , Hahn H. T.
Published: July 2023

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Fundamentals of Workpiece Localization: Theory and Algorithms
Authors: Li Z. X. , Kang B. , Gou J. B. , Chu Y. X. , Yeung M.
Published: July 2023

In this paper, we present an algebraic algorithm for workpiece localization. First, we formulate the problem as a least-square problem in the configuration space Q = SE(3) × ℝ3n, where SE(3) is the Euclidean group, and n is the number of measurement points to be matched by corresponding home surface points of the workpiece. Then, we use the geometric properties of the Euclidean group to compute for the critical points of the objective function. Doing so we derive an algebraic formula for the optimal Euclidean transformation in terms of the measurement points and the corresponding home surface points. We also give for each measurement point a system of two nonlinear equations from which the corresponding home surface point nearest to the measurement point can be solved. Finally, based on these analytic results we present an iterative algorithm for obtaining the complete solution of the least-square problem.
Optimization and Interpolation Issues in Evaluating Actual Geometric Deviations From CMM Data
Authors: Nassef Ashraf O. , ElMaraghy Hoda A.
Published: July 2023

Coordinate measuring machine data are used to determine whether ornot parts conform to the specified tolerances. Much of the analysis involve optimization to evaluate the values of actual geometric deviations detected by CMM inspection. If the optimization method does not arrive at the global minimum value of a deviation and settles for a higher value instead, a part could be unnecessarily rejected during inspection. This paper proposes the use of genetic algorithms as global optimizers to evaluate geometric deviations and shows their advantage over the currently used methods through examples. Since the definition of some deviations in the new GD&T standards, such as the local size, do not lend themselves easily to optimization algorithms using the CMM data directly, the presented work proposes the approximation of the manufactured surfaces using NURBS for facilitating the evaluation of such deviations. Finally, the paper recommends the use of some genetic parameters to decrease the computational intensity associated with using the genetic algorithms.
Dimensional Measurement Data Analysis: Part II — Minimum Zone Evaluation
Authors: Choi Woncheol , Kurfess Thomas R.
Published: July 2023

Modern inspection systems such as coordinate measurement machines generate discrete three dimensional coordinates representing points from the surface of a manufactured part. These coordinates must be compared to a target or nominal geometry to determine if the part conforms to specification. Quite often a least squares fit or a min-max fit are employed to determine the geometry of the part. However, as described in Part I of this paper, acceptable deviations are often specified as tolerance zones about the nominal geometry. Part I of this paper presents a zone fitting algorithm having an objective of placing the sampled data points within a specified tolerance zone. If all of the points fit within the zone, the part is passed. This pass/fail result does not provide information as to the quality of the part. The question that is not answered is “Did the points just fit into the tolerance zone, or did the points fit with ample space remaining?” This question is important as it informs production personnel whether their processes are operating well within specifications or just barely within specifications.

In this part of the paper, the zone fitting method developed in Part I of this paper is extended to a minimum zone evaluation. This can be formulated as a one dimensional search for the critical value of the zone fitting objective function, which is to place all sampled points within the zone via geometric rigid body transformations (e.g., rotations and translations). The minimum zone evaluation algorithm developed in this paper can be applied to an arbitrary geometry profile evaluation, and a number of examples are presented to demonstrate its capabilities.
On the Manufactured Part Model Approach to Characterize Shape
Authors: Fussell Paul S. , Novic Bradley
Published: July 2023

The methodology of the manufactured part model, MPM, a means to reduce measurement data to meaningful shape information, is elucidated. The MPM permits one to fit a parameterized model of the nominal geometry to the set of surface location data resulting from measuring a part. This note describes recent successes using the MPM method, particularly in discovering the true deformed shape: this insight has led directly to improved schemes for process operation which reduce part variation, as well as quantifying process capability. We further discuss suitable applications of the methodology, areas of immediate and longer term research, and applications to more complex assemblies.
Fault Diagnosability Enhancement Through Sensor Optimization in Multi-Fixture Assembly Systems
Authors: Khan Ashraf , Ceglarek Dariusz , Ni Jun
Published: July 2023

The effectiveness of fault diagnosis in assembly is contingent on the effectiveness of the sensor measurement of assembled parts. Using a diagnosability enhancement methodology for a single fixture, a means to achieve an optimal sensor configuration for a multi-fixture assembly of sheet metal parts is proposed. A Hierarchical Group description of the assembly is used to build a State-Transition representation which, with fixture CAD information, is used in multi-level hierarchical optimization to arrive at the optima. A defined Coverage Effectiveness Index quantifies fault isolation performance. The index also serves to evaluate the performance effectiveness of the measurement station location and change in the sensor number. The approach has significant utility in automotive body assembly where system complexity makes the choice of sensor location vital to fault isolation performance. Examples using multi-fixture simulated automotive body assembly sequences are provided to illustrate the methodology.
Uncertainty Management for CMM Probe Sampling of Complex Surfaces
Authors: Edgeworth Robert , Wilhelm Robert G.
Published: July 2023

A method is presented to reduce the measurement uncertainty for surface point inspection when using a Coordinate Measuring Machine (CMM) equipped with a mechanical touch trigger probe and rotary probe head. The largest contributor to measurement uncertainty in this situation is the variation in probe deflection before a trigger signal is sent to the CMM. This variation is dependent on the angle between the major axis of the touch trigger probe and the surface normal of the point being probed. When the major axis of the probe body is nearly collinear with the surface normal at the sampled point, the probe deflection variation decreases significantly. Experimental results show that the uncertainty due to repositioning the probe head to achieve this near collinear orientation is considerably less than the uncertainty associated with probe approaches where there is a large angle between the major axis of the probe and the surface normal of the point being probed. This result is particularly applicable to the measurement of complex surfaces.
A Framework on Automated Root Cause Identification Methodology Using Fuzzy Neural Network Reasoning
Authors: Tadayon Farhad , Lee Jay
Published: July 2023

Early recognition of assembly interface problems can save noticeable time and money by eliminating the red tape and procedural activities among different and often redundant organizations. Automated Root Cause Identification System (ARCIS) is a quality control expert assist database system which can suggest and identify the root cause of an assembly variation problem based on the history of the previous occurrences and in conjunction with the on-line multivariant statistical information obtained from the principal clusters of variations. A fuzzy Cerebellar Model Arithmetic Computer (CMAC) neural network system serves as a “watch-dog” to perform feature extraction of the output from the ARCIS and compare its pattern with previous patterns. As a result, the trends of performance degradation can be measured through this integrated methodology.
Dependency Relations in Product Families
Authors: Shek Stanley C. , Chan Stephen C. , Lee John W.
Published: July 2023

A product is usually composed of other products with a number of different variants. The user may select among a number of options for certain features of the product. The option selected for a feature may, in turn, determine the available options for other features or the available variants of certain components to be used in composing the product. This paper proposes to extend the ODMG data model to support the concept of a product family and some common dependency relations among its features and components. It classifies these dependency relations based on the features and components involved and their respective values and cardinality. A graphical notation is also included.
Integration of Activities to Step Product Data Models Using Object Oriented Methodology
Authors: Ghodous Parisa , Vandorpe Denis
Published: July 2023

A modern engineering environment needs to solve the problem of integration between different applications. Recent works on product data integration have led to STEP (international Standard for Exchange of Product data models). Unfortunately STEP doesn’t emphasize on the reprsesentation of activities. In this paper, firstly we describe a methodology for classification of activities and then using the object-oriented approche, we define a model which integrates the STEP product data models with activity data models. Some examples in the domain of kinematics analysis and geometric modeling are included.
Manufacturing Information Systems Integration: A Proposal Using SIP
Authors: Jardim-Gonçales Ricardo , Barata Manuel M. , Sousa Pedro C. , Steiger-Garçao Adolfo , Pamiés-Teixeira Jorge
Published: July 2023

Usually, the available software packages qualified to run within the manufacturing world were developed without a global view of the manufacturing system. When a factory wants to move towards Computer Integrated Manufacturing (CIM) the integration of these commercial tools should be considered.

Therefore, a possible approach to enhance production can be to consider the integration of already existent system’s tools using a standard data exchange format. UNINOVA - Institute for the Development of New Technologies, in the scope of a European project, has been developing a STEP (ISO10303) based toolkit (SIP) to aid the integration of these applications and the management of the achieved integrated system.

Up to the moment some managerial and engineering software applications have been integrated using SIP inside industrial companies. The software packages used, the steps followed to integrate them, and the results obtained using SIP in these manufacturing environments will be described and commented within the paper. Also, the internal architecture of SIP and the global information system architecture based on standard models are presented, highlighting the implementation aspects occurred during the developments for the industry.
Modeling Product Structures and Engineering Changes Using Express Representation Scheme
Authors: Peng Ting-Kuo , Trappey Amy J. C.
Published: July 2023

In recent years, information has become an important resource for managing the life-cycle activities of product development. Due to the heterogeneous and distributed nature of product R&D, related product data in electronic forms are often poorly managed even within the product design phase alone. As the result, an international standard for product data exchanges, STEP, is emerged and developed cooperatively by many organizations. This paper describes two main data models using STEP-EXPRESS representation scheme. One model is defined to represent the assembly structure of a product, the other is to describe the process of engineering changes in the design/redesign stage. These two models are essential in conveying the most updated product information for the concurrent engineering practice, particularly for complex product designs. Using the STEP-compatible data modeling technique, the product data integration between product structures and detailed CAD data is achieved without further efforts. Data involved in all product life-cycle activities are captured under the same format without any information loss. Furthermore, the integrated architecture for a heterogeneous design environment is also described that aims to achieve the information communication and sharing among various design systems.
Automatic Feature Recognition Using a Neural Network Technique
Authors: Chan Chu-Chai (Henry) , Fischer Gary W.
Published: July 2023

For a concurrent engineering environment, two critical steps are needed. The first step is to share information between design engineers and manufacturing engineers. The second step is to understand the meaning of the information being shared. This paper focuses on an automatic feature recognition method for interpreting part feature information created by a design engineer. Automatic feature recognition can help understand the meaning of features and provides the basis to link CAD to CAM.

A big problem for automatic feature recognition is that the increasing number of recognized features causes the process of recognition to become very complicated. The conventional feature recognition methods, such as graph-based and rule-based recognition, construct graphs or need experts to define an extensive set of sophisticated rules and use exhaustive searches to identify features. An artificial neural network methodology is proposed to avoid these problems. Neural networks can recognize features very quickly and the trained features can be interpreted directly from the geometric information instead of relying on expert-defined rules.

A common difficulty encountered when using neural networks is that the training process can take a long time or in some cases even be impossible. In order to increase the learning rate, this paper presents a neural network algorithm called CMAC (Cerebellar Model Arithmetic Computer). The paper also demonstrates other advantages of using neural networks, such as the recognition of partial features and compound features.
A Framework for Logistics System Metrics
Authors: Byers Jill E. , Landers Thomas L. , Anderson Steve
Published: July 2023

With global competition intensifying and companies battling to keep market share, it is imperative that they carefully manage costs while maintaining service levels. Many companies are considering outsourcing transportation and distribution functions as a way to reduce costs. Before costs can be reduced in a particular division, these costs must be defined and a method found for their calculation. In addition, companies need ways to measure service. Well-defined metrics can help a company measure costs and service and analyze tradeoffs between the two.

Metrics are quantitative measurements that track certain processes within a business (refer to Figure 1). These processes might seem simple (e.g. shipping a load of computer chips). However, even simple processes can become complicated when the underlying costs such as carrying, holding, material handling, and transportation costs, eta are considered. Since many processes have multiple sub-levels, it can be very difficult to identify which metrics to use.

This paper develops a list of potential metrics for distribution and transportation operations, and constructs a conceptual framework.
Communications Technology Requirements for Virtual Warehousing
Authors: Walker Bryan H. , Landers Thomas L. , Stuart Don , Kasilingam Raja , Rupert Clyde
Published: July 2023

Global logistics is the new frontier for information technology. World trade is expected to increase four-fold to over US$16 trillion by the year 2010. Logistics represents over US$600 thousand million in the United States of America (USA), which is roughly equivalent to the cost of health care in that country. Additionally, logistics is the second largest employer of new college graduates in the USA. Because of the importance of logistics, the National Science Foundation in the USA sponsors The Logistics Institute (TLI), and its predecessor the Material Handling Research Center (MHRC) to conduct basic and applied research, continuing education, and technology transfer in logistics. TLI is an Industry / University Cooperative Research Center operated jointly by the Georgia Institute of Technology and the University of Arkansas. It is sponsored by seventeen member companies in addition to the National Science Foundation. TLI has close relations with the Fraunhofer Institute at the University of Dortmund in Germany and is establishing cooperation with Gintic Institute of Manufacturing Technology at Nanyang Technological University in Singapore.
Non-Linear Finite Element Analysis of the Contact, Strain and Stress States of a Bolt-Nut-Washer-Compressed Sheet Joint System
Authors: Váradi Károly , Joanovics László
Published: July 2023

A non-linear finite element model with contact elements was developed to evaluate the contact state of a bolt-nut-washer-compressed sheet joint system.

Applying the proper material law the non-linear behaviour of the members of the joint was studied in terms of the clamping force. Based on the FE results the load distribution among the threads in contact and the real preload diagram of the system were evaluated.

To produce the required clamping force at medium strength bolts it is advisable to use heat-treated washers instead of lower strength ones.
Thermoelastoplastic Stresses in a Rotating Disk of Temperature Dependent Properties With Temperature Gradient
Authors: Jahanian Shahriar
Published: July 2023

There are numerous situations in industry where rotating disks are subjected to cyclic thermal loading. If the operating thermal loading remain in the shakedown region, no plastic deformation occur and the system works safely. However, depending on the speed of cooling and other operating situations, inelastic deformation and incremental growth of the structure in question may occur. This may lead to the incremental deformation, and eventually incremental collapse of the mechanical components. Accordingly. it is essential to develop a numerical method to predict the ine|astic response of mechanical components to the thermal or thermo-mechanical loading. Analysing the aformentioned problems is quit complex, accordingly in this reaserch effort we begin with a simple case.

In this paper a numerical method is presented for estimating the thermoelatoplastic stresses developed in a rotating disk, subjected to temperature gradient. The disk’s temperature in the radial direction varies from 100 °F temperature to 1500 °F. The steady state temperature distribution is evaluated using the familiar Carslaw and Jeagar equations. For inelastic behavior of the disk a combined analytical and numerical method is presented. The properties of the material are assumed to be temperature dependent. The material is also assumed to be characterized by nonlinear strain hardening. For this analysis a quasi static uncoupled thermoelastoplastic solution is presented. The problem is also solved for a case when the properties of material are not function of temperature. The effect of temperature dependency of the material on the results is investigated.
Experience With the Application of Risk Concepts in Developing Equipment Prioritization Systems
Authors: Tallin Andrew G. , Conley Michael
Published: July 2023

As consultants to refining and petrochemical companies, Det Norske Veritas (DNV) has been involved in developing risk based prioritization and management systems for a number of years. This paper follows DNV’s experience as it developed these methods, beginning with the initial concepts through the completion of several projects. The paper discusses some of the efforts that have been made to standardize the application of risk based prioritization.

In applying risk based inspection, the likelihood and consequence of each individual item is considered and the result is a ranking system that identifies and ranks failures on a uniform scale. In virtually every study DNV has performed, the “Pareto Principle” has been confirmed: at least 80% of a plant’s total risk exposure is due to at most 20% of the equipment. In many plants, the 90% of the risk is due to only 10% of the equipment. The principle is demonstrated here by presenting the overall distributions of risk that have resulted from prioritization studies that DNV has done.

The highest expected return is produced by prioritizing maintenance and inspection efforts to concentrates on this subset of items.
Systems Engineering of Complex Commercial Systems
Authors: Hale Pat
Published: July 2023

The formal Systems Engineering process was developed by the Department of Defense and its contractors in the late 1950s, during the development of the first ballistic missile systems, and was first documented as a standard process in 1969 in MIL-STD 499, Engineering Management. The process is intended to provide an overall framework for managing the development and acquisition of complex defense systems, describing an orderly sequence and supporting documentation to be implemented by both the government customers and development contractors. During the definition of systems engineering, defense and aerospace systems clearly represented the most complex products undertaken by the U.S. scientific, engineering, and industrial communities. As commercial products, particularly those spanning many technical disciplines, began to exhibit the same degree of complexity, the companies responsible for these commercial products have started adapting the DoD systems engineering process and practices for use in commercial product development projects.
Balancing Management and Technical Considerations for Environmentally Responsible Engineering
Authors: Kistler Ernest L.
Published: July 2023

This paper is about ways of visualizing and achieving harmonious balance between technical and managerial considerations with regard to environmental aspects of the design of complex systems. Environmental considerations strongly involve GeoSpatial Technology (GST) in the overall Life Cycle Analysis (LCA) of a total Product Realization Process (PRP). Hence, GST is a critical Emerging Technology essential for competitiveness and sustainable development in a global economy. Human dimensions of sustainable development are discussed as part of Total Productivity Management (TPM), and it is shown that certain aspects of the so-called “reengineering revolution” are not robust in the sense of Taguchi (and therefore are not sustainable). The concept of profit is discussed, and management considerations for maximizing corporate profit are examined through use of Kistler’s Productivity Gain Function (PGF) or Generalized Productivity Gain Function (GPGF) to account for numerous complex issues.
Engineering of Complex Systems in the 21st Century
Authors: Crisp H. E. , Franke M. E.
Published: July 2023

A U.S. Navy-initiated annual workshop program for promoting wise technology investment in the engineering of complex systems in the 21st century, especially in systems engineering technology, is described. Descriptions of the first two workshops held in 1994 and 1995, including some general results that were obtained by the focus groups, are given. Because of fundamental changes in the way the Department of Defense (DoD) currently acquires goods and services, the third workshop is designed to couple the focus group discussions and expectations closely with the DoD mandated concepts of Integrated Product and Process Development (IPPD) and Integrated Product Teams (IPTs). Primary focus group tasks related to practices to improve the engineering of complex systems within the IPPD context are discussed. Some characteristics of complex systems are presented. A few recent studies on engineering and management processes and DoD and industry experiences related to engineering of complex systems outside of the workshops are reviewed. Human resources and the changing role of the engineer are discussed.
CAE Durability Simulation of Vibration Sweep Tests
Authors: Hu J. M. , Garfinkel G.
Published: July 2023

This paper presents a simulation method for vibration sweep tests of components and interconnects. The paper introduces the computational method to determine cumulative fatigue damage as a function of the stress-frequency response, the sweep rate and the testing time, demonstrates the “local stress-strain” approach to predict the non-linear (elastic-plastic) stress at the potential failure sites through the linear dynamic finite element analysis in the frequency domain. As an application example, the analysis procedure and computational results for the aluminum wire-bonding between a silicon chip and printed wiring board are presented.
Thermomechanical Stress Analyses of Plated-Through Holes in PWB Using Internal State Variable Constitutive Models
Authors: Fu Chiayu , Ume I. Charles , McDowell David L.
Published: July 2023

In application of multiaxial fatigue theories, extrapolation of concepts developed from uniaxial fatigue research must be used with caution. Previous related research on plated-through hole (PTH) fatigue investigations has been based on so-called effective stress/strain methods, which did not account for the fact that fatigue crack nucleation and growth is observed to occur on specifically oriented planes. Moreover, previous related thermal stress/strain analyses on PTH has been based on so-called bilinear constitutive relations for modeling copper plating with a linear kinematic hardening assumption, and this cannot capture many aspects of cyclic stress/strain behavior during thermal excursions. In this paper, thermal stress analyses using thermodynamics-based constitutive models of metallic consituents of PTHs are conducted by finite element package ABAQUS (1995) for multiaxial fatigue studies. Two types of PTHs (via) are investigated: ordinary empty PTH and PTH with solder filler. Two thermal profiles which simulate temperature fields in service are applied, with one experiencing the glass transition temperature of FR4. Residual stresses generated from previous process temperature history are considered. From the stress analyses, critical plane orientations for tensile type and shear type fatigue cracks are located.
Thermal Management of Flip Chips on Printed Circuit Boards
Authors: Zhang Ron , Peugh Darrel , Myers Bruce
Published: July 2023

The general trend in the automotive electronics industry dictates increased power dissipation on ever shrinking packaged components, giving rise to greater power density. Flip chips on ceramics have long been used for favorable thermal management and reliability. With the drive to cut costs, printed circuit boards are replacing ceramics for many applications, which requires different thermal management techniques. This paper presents some of the techniques that can be used to achieve comparable thermal performance on printed circuit boards.
Polymer Based Flip Chip Interconnect Materials for Monolithic Integrated Circuits
Authors: Strifas Nickolaos , Christou Aris
Published: July 2023

The results of simulation, and material performance testing of anisotropic conductive polymers for flip chip interconnects necessary for power MMICs are reported. The flip chip interconnects are designed to connect source metallization to a common ground plane, and also to provide for heat sinking paths to a ceramic substrate. Finite Element Analysis results are also reported simulating the thermal mechanical stresses present during high frequency operation at a frequency of 1–10 GHz.