bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computerized Reconstruction of Building Fires
Authors: Lilley David G. 
Published: April 2021

Abstract
A fire development simulation model is described which provides estimates of the amount and temperature of the smoke layer produced, the evolution of toxic gases, and the amount of time available from the onset of fire for the safe departure of occupants. Its results can be used to determine the key features of the fire evolution and the corresponding danger to occupants. Studies of this type help to validate or deny the suggested fire scenario and witness statements. Mathematical modeling thus helps to discriminate between alternative fire scenarios by evaluating the consequences and comparing them with observations.
The software consists of data, procedures, and computer programs which simulate important time-dependent phenomena involved in residential fires. Based on sound scientific and mathematical principles, predictions are made of the production of energy and mass (smoke and gases) by one or more burning objects in one room, based on small or large scale measurements. The buoyancy-driven transport of this energy and mass through a series of user-specified rooms and connections is then computed (doors, windows, cracks, etc.). The resulting temperatures, smoke optical densities, and gas concentrations (after accounting for heat transfer to surfaces and dilution by mixing with clean air) are linked to the problem of egress. The evacuation process of a set of occupants may be simulated, accounting for delays in notification, decision making, behavioral interactions, and inherent capabilities.
The Use of Advanced Transient Structural Codes to Study Interior Gun Dynamics
Authors: Wilkerson Stephen 
Published: April 2021

Abstract
Three-dimensional numerical models used to analyze the in-bore dynamics of kinetic energy projectiles are presented. The intricate modeling process, boundary conditions, and assumptions used in the analysis are given. Numerical results are analyzed and presented to show the importance of three-dimensional numerical studies. Finally possible areas of concern and future improvements in the numerical techniques used are reviewed.
A Two-Level Multigrid Algorithm for Solving 3-D Quadratic Finite Element Models
Authors: Pressburger Yoram , Perucchio Renato , Field David A. 
Published: April 2021

Abstract
A two-level multigrid algorithm for solving a quadratic finite element models containing tetrahedral meshes is presented. The basic idea is to generate two nested finite element models, first a linear model and then a quadratic one embedded hierarchically into the linear one. The exact solution to the linear model is computed and a two-level iterative procedure is used to solve for the quadratic model. In particular, the Successive Over Relaxation (SOR) method is used for the smoothing iteration on the quadratic model in each two-level cycle. A numerical study is carried out to determine how the relaxation factor and the number of SOR iteration in each two-level cycle influence the convergence rate of the complete algorithm. The stopping criterion for the iteration is based on the notion that the error in the iterative procedure will be of the same order as the error in the finite element approximation. Finally, the efficiency of the algorithm is evaluated by comparing the computational time with that of an exact solver based on Gauss elimination. Results indicate that the present algorithm produces substantial saving of CPU time.
Analytical Evaluation of the Integrals Appearing in the Boundary Element Method for Some Problems in Mechanics
Authors: Bora Jugma N. 
Published: April 2021

Abstract
The boundary integral equation method or simply the Boundary Element Method (BEM) is now considered to be a powerful tool for solving problems in mechanics. A large number of the line and area integrals appearing for two-dimensional problems, in the BEM, can be represented as linear combinations of four singular functions. These integrals that are generated are products of the approximating polynomials and one or more of the four singular functions. These integrals can be evaluated numerically or analytically. The advantage of numerical integration is that the shape of the boundary can be of any complexity. The big disadvantage is that another source of error, besides the polynomial interpolation, is added into the process due to the approximation of the integrand for numerical integration. The singular nature of the fundamental solutions further exacerbates this disadvantage. In analytical integration, the form of the boundary must be assumed. The usual representation is a sum of straight-line segments. Currently, analytical expressions are available only for a few formulations and they are valid only for zero- and first-order polynomials. In this paper analytical expressions of the integrals are obtained for approximating polynomials of any arbitrary order. The fundamental solutions of the Laplace, Biharmonic and the equation of Plane Elastostatics are considered. The validity and advantage of using these integrals are shown by some simple problems in mechanics that have theoretical solutions.
Self-Adaptive Algorithm for Efficient Computation of Elasto-Plastic Material Process
Authors: Lee Sang H. 
Published: April 2021

Abstract
Due to the path-dependent nature of the plastic material, plastic strains are calculated by an incremental procedure and the total strains are obtained by summation in the numerical computation. MSC/NASTRAN employs an adaptive subincremental process at the Gauss point level for accuracy and efficiency. Various options for yield criteria and hardening rules are implemented. The generalized effective plastic strain increment is derived to accommodate various yield criteria. By virtue of some salient considerations in implementing the numerical procedure, difficulties associated with unloading have been resolved. This paper focuses on the adaptive features which allowed efficient computations of elasto-plastic material processes commonly comprising unloading, reloading and nonproportional loading. Select examples show novel applications of the elasto-plastic material capabilities.
A Simple and Efficient Large-Displacement Formulation for Beam Elements
Authors: Tang Xiaodong 
Published: April 2021

Abstract
A simple and effective finite element formulation of beam-column stiffness matrix with the consideration of second-order displacement is presented. The derived second-order stiffness matrix is the simple addition of the small-displacement stiffness matrix and a few other component matrices. The matrix is derived closed form and no integration is necessary during the formation of the element stiffness matrix. The simple additive relation makes it easy to understand the composition of the second-order stiffness matrix and the meaning of each component matrix. The closed-form formulation eliminates the potential numerical error and considerably reduces the amount of computation thereby, increasing the computing speed. The standard finite element approach presented in this paper makes the beam-column compatible with other finite elements and can be incorporated into existing finite element programs with little modification. The analysis of a simply supported beam with axial restraints using the beam-column element shows a good correlation with the test results.
GRAPE: Finite Element Analysis and Shareware
Authors: Luczak E. R. , Letan Q. 
Published: April 2021

Abstract
Use of Finite Element Methods are becoming more prevalent as we move into the 1990’s. More engineers and engineering technologists than ever before are graduating from universities and colleges with knowledge and expertise in the method. A wide assortment of programs are now available that run on micro’s, mini’s, mainframes, and super computers with a broad spectrum of capabilities and costs. Enter the Shareware concept. Shareware does not mean free software. It does mean that software may be freely distributed to promote it’s use and therefore is available to the user at very low cost. This paper discusses a highly interactive Finite Element Analysis system specifically suited for engineers and technologists. GRAPE (Graphic Real-Time Analysis Programs for Engineering) is a series of Shareware programs created to provide the tools necessary to obtain an applied understanding of the technique. GRAPE allows an easy transition to the usage of more complex and powerful codes. A number of sample models are created and analyzed using one of the GRAPE programs, called GCST, to illustrate the ease with which real world applications can be modeled and studied. It is GRAPE’s responsive interactive approach that allows the user to quickly modify the condition of a model and thus note the effects that makes the study of the method appealing and unique. Most experienced users will agree that knowledge of a software package is necessary but the important aspect of being proficient in the method is the synthesis of how to properly model a problem. GRAPE allows the engineer to solve problems easily and quickly to obtain this desired level of competence.
Approximate Solution of Nonclassically Damped Systems
Authors: Ma F. , Hwang J. H. 
Published: April 2021

Abstract
In analyzing a nonclassically damped linear system, one common procedure is to neglect those damping terms which are nonclassical, and retain the classical ones. This approach is termed the method of approximate decoupling. For large-scale systems, the computational effort at adopting approximate decoupling is at least an order of magnitude smaller than the method of complex modes. In this paper, the error introduced by approximate decoupling is evaluated. A tight error bound, which can be computed with relative ease, is given for this method of approximate solution. The role that modal coupling plays in the control of error is clarified. If the normalized damping matrix is strongly diagonally dominant, it is shown that adequate frequency separation is not necessary to ensure small errors.
Precision Machines: Diagnostics of Vibration Through Modal and Finite Element Analysis
Authors: Prakash V. , Montague R. J. 
Published: April 2021

Abstract
This paper presents the diagnostics of the effects of vibration on the precise placement of electronic components in a surface mount assembly process. Experimental Modal Analysis using present day software/hardware as well as a three dimensional finite element model are performed on the machine structure. Correlation between the experiment and finite element model are also performed and the strength of using the finite element model as a test model for contemplating any design alterations are presented.
Finite Element Mesh Generation With Computed Tomography Scan Data
Authors: Wei C. Stan , Skinner Clark D. 
Published: April 2021

Abstract
This report presents a new finite element meshing approach, put forth by Q-Mesh, to producing 3-D mesh models for solid objects whose geometries can be captured with an industrial computed tomography (CT) scanner.
The Q-Mesh system utilizes a series of deformable grid templates and component solid regions to create a 3-D global mesh that can be divided into subregions of connected meshes located within the component solids. It provides an interactive graphics interface through which the user can design and visualize 3-D, multiregion meshes consisting of well-formed wedge and hexahedron elements.
The unique solid-modeling algorithm implemented in Q-Mesh allows the system to generate, automatically, matching finite element meshes across any number of solid regions. This unique feature makes Q-Mesh an ideal mesh generator for finite element solvers geared to the simulation of general multiregion problems. Furthermore, the use of a multiregion mesh model as the source for analysis models representing variations of a single-region mesh, as unions of selected subregions, has proven more time efficient and cost effective than the single-region alternative where each variational model has to be regenerated from scratch.
This report focuses on the utility of a CT scanner as a geometry input processor to Q-Mesh. The generation of finite element models for a solid object represented in the form of sliced CT scan data involves two phases: (1) converting the sliced CT scan data into a series of stacked solids; and (2) utilizing Q-Mesh’s interactive design tools to build mesh models based on the reconstructed solids. A number of examples are given to demonstrate the general procedure and unique capabilities of the new meshing approach.
Teaching Advanced CAD Concepts
Authors: Tombers Paul A. 
Published: April 2021

Abstract
The purpose of this paper is to share my experiences with my fellow engineers and educators involved in teaching advanced CAD courses. Advanced CAD in the context of this paper simply means teaching topics that are not usually covered in an introductory CAD course.
Appropriate advanced CAD topics can be categorized into two major areas; using the advanced features of the CAD software and customizing the CAD system to meet individual needs. The advanced features of the CAD software presented in this paper will include the use of attributes and the creation of three-dimensional models. Customizing the CAD system will be accomplished by modifying various existing system files and writing macro programs that accomplish specific tasks for the CAD user.
The paper presents detailed explanations of the above mentioned topics, assignments that can be used in the classroom and in the CAD laboratory, and a sample course outline.
A Work Cell Animator for Robotics Instruction
Authors: Toogood R. W. 
Published: April 2021

Abstract
For introductory robotics courses with high student/robot ratios, the lack of robotic hardware can be a problem in providing adequate hands-on experience with robot programming. Used in place of actual robots, computer animation can provide an acceptable substitute to gain insight into robot kinematics and programming. As well, the animation can be used to verify robot programs developed off-line as to movement sequence, illegal moves, and obstacle avoidance. This paper presents a detailed analysis of an algorithm used in a microcomputer animation of a robot moving in a work cell. Topics discussed include representation of the robot and objects in the work cell, specification of the view frame, perspective projection, and several techniques for producing the animation.
The Development of a Generally Applicable Digital Computer Spokes Tyre Model
Authors: El-Nashar M. , Watany M. 
Published: April 2021

Abstract
An extensive survey is presented for the analysis of both in-plane and out-of-plane pneumatic tyre models. The single plane tyre model[2,9] is developed to represent the influence of tyre width by using many conical shell shapes built from spokes with different head angles. The general form of the new tyre model is based on the well-known single plane steady state version of the tyre model. The mathematical analysis and geometrical form of the developed model is given.
A computer program is designed for desk top P.C. without costly running times which makes it useful for representing the pneumatic tyre/road contact forces. Model assumptions and parameters were chosen to give qualitative and quantitative agreements between theoretical and experimental results.
The paper also presents an experimental study for investigating the influence of working conditions on tyre/road contact forces. The experimental results were carried out using the steady state tyre testing machine constructed in the Automotive Engineering Department, Helwan University [3,10]. Experimental findings for 145 SR 13 tyres are compared with the new model theoretical results. Experiments on real tyres show good agreement with the predicted theoretical results of the new generally applicable model.
On-Line Food Processing Robotics: A First Step
Authors: Thompson J. C. , Holcombe W. D. , McMurray G. V. , Wyvill J. C. 
Published: April 2021

Abstract
Food processors today are facing a number of challenges that increasingly make the application of robotics both attractive financially and necessary for their survival. These challenges include foreign competition, a dwindling workforce, increasing safety regulation, demands for increased throughput, and a growing concern for quality improvement to name a few. To date however, robotics have not been successfully employed in this industry due to a number of significant technical shortcomings including speed, end-effector adaptability, environmental ruggedness, and cost. This paper describes two prototype robotic workcells designed for the poultry industry. One cell handles packaged product while a second manipulates raw chicken for cut-up. The challenges involved are described in detail as well as the preliminary results of initial designs and trial operation. From this research a number of focus areas have been identified for future research. Future plans include the development of smart sensor equipped end-effectors, visual guidance systems, force feedback control, and truly universal gripper designs.
Precision Positioning With Force Sensing and Fuzzy Control
Authors: Gürocak H. , de Sam Lazaro A. 
Published: April 2021

Abstract
The use of force feed back for manipulator control is a well established technique. However, measurement inaccuracies and system noise precluded any practical deployment of this method. In this paper an approach to force sensing and measurement will be discussed. A method of accounting for measurement errors and system noise will be introduced. The use of fuzzy control for fine positioning will be presented. The method described in this paper provides an inexpensive alternative to vision systems using a software approach.
A Spherical Hierarchical Representation for Robot Motion Planning
Authors: Pasqual del Pobil Angel , Serna Miguel A. 
Published: April 2021

Abstract
A simple and practical model with applications in 3D motion planning is presented. The new model is based on a double spherical hierarchy of detail to represent solid bodies.
First, each element making up the robot and the obstacles is approximated by means of a set of exterior spheres which are automatically defined. Second, another set composed of interior spheres is generated. These representations define a hierarchy, since they can be redefined as many times as necessary: starting with two spheres per element, the approximation may be improved until it contains hundreds of spheres. Moreover, they converge to a zero-error representation.
The proposed spherical model leads to a simple treatment for the problem of dynamic collision detection, and it is further applied to collision-free path planning for robot manipulators in 3D.
Precise Vision-Based Tracking of an Autonomous Floor-Maintenance Vehicle
Authors: Baumgartner E. T. , Skaar S. B. , Strebinger R. B. 
Published: April 2021

Abstract
This paper describes a unique approach to the estimation and control of the trajectory of an autonomous floor-maintenance vehicle. Several requirements and challenges attend the floor-maintenance objective which are shown experimentally to be addressed using our new formulation. The procedure involves a combination of visual sensing, internal wheel rotation sensing, extended Kalman filtering, and teach/control operation.
Steady State Optimal Control Approach for Aluminum Turning
Authors: Suliman S. M. A. , Hassan G. A. 
Published: April 2021

Abstract
A steady state control algorithm has been developed. The algorithm is based on steady state process models established and used to provide algebraic control model. The control model can be applied for on-line computation of new levels of the aluminium turning process control variables required to compensate for the detected errors of process controlled variables. Workability of the developed control algorithm and its performance are evaluated by computer simulation. Although the control methodology is developed for aluminium turning process, it is general and can be applied to any machining process.
Design and Implementation of Self-Tuning Regulators for Active Noise Control
Authors: Shoureshi Rahmat , Matsuyoshi Yasuhiro 
Published: April 2021

Abstract
Acoustic noise has become an increasingly important problem, especially in industrial societies. The main reason being the increase in usage of machines in virtually all aspects of our lives, higher population densities, and concerns about the health consequences of exposure to acoustic noise. Passive noise control methods work well for relatively high frequency noise, but become progressively more expensive and less effective as one considers control of lower frequency noise. Development and implementation of an adaptive active noise controller is presented.
Automated Hybrid Analysis of Surface Mounted Electronic Assemblies
Authors: Wong Tin-Lup , Wang Junshi , Stevens Karl K. 
Published: April 2021

Abstract
Simulations of surface mounted electronic assemblies under general mechanical loading conditions have been performed using an hybrid analytical/experimental analysis approach. This method combines analytical techniques with experimentally determined load-deformation characteristics of the surface-mounted assemblies to predict loadings and deformations of the assemblies. An automated analysis procedure which integrated the finite element method, optimization theory and the hybrid analysis approach was developed. This procedure can be used to study the strength of the surface mounted devices located anywhere on a printed circuit board subjected to the specified loading conditions.
Automatic Dimensioning From 3D Solid Model With Feature Extraction
Authors: Oh Je Hwan , Lee Kunwoo 
Published: April 2021

Abstract
A scheme for automatic dimensioning of a part created by B-rep based modeling system is presented. Since size dimensions and location dimensions are required for defining part features in engineering drawings, part features are extracted first from a B-rep model for the automatic dimensioning.
Faces which constitute a feature are found in two steps: the first by the edge-initiated approach and the second by the boundary-initiated approach. The recognized features are stored in a graph whose nodes are feature faces and edges represent their connections.
Once all the features are recognized, a linked list of identification points, called a dimension link, is generated automatically for each direction of dimensioning the part. Then, size and location dimensions of the part features are directly created from the dimension link and placed on the most descriptive view.
Tool Approach Directions for Machining Protrusion and Depression Features in an Object
Authors: Karra Chandrasekhar , Phelps Thomas A. 
Published: April 2021

Abstract
The success of any industry in today’s highly competitive market is largely dependent on its ability to produce quality products, quickly and at low cost. Evaluating the effect of a product design on its manufacture is crucial in developing efficient designs. Any potential manufacturing problems detected at this stage can be corrected by modifying the design, leading to shorter product development cycles and lower production costs. This paper presents an algorithm to determine feasible tool approach directions. The algorithm is based on detecting if any part of the object obstructs the tool path. The basis for the algorithm is determining feasible approach directions and clearances around a planar polygonal face. The algorithm is applicable to both protrusions and depressions. The information is useful in performing manufacturability analysis of designs and develop process plans.