bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subregion Analysis by the SBSF Method in Commercial Finite Element Software
Authors: Knight Charles E. 
Published: March 2021

Abstract
It is difficult to analyze a large, complex structure in sufficient detail to obtain accurate results everywhere. One approach to this problem is simply to refine the whole structure model in the regions of interest which is obviously costly. Another approach is to identify a subregion of the structure and develop a separate refined model of the subregion. The most recent method for subregion analysis presented in the literature[1] is called the Specified Boundary Stiffness and Force (SBSF) method. While the method is relatively straight forward and efficient, none of the commercial code vendors has yet included an implementation.
This paper gives a brief review of the theory behind the method and then describes its application in two commercial finite element programs. Examples of the application of this method to the problem of a plate with a center hole in tensile loading are presented using ANSYS® and CAEDS(IDEAS)®. The results compare favorably to the theoretical value and show significant improvement in accuracy over the specified boundary displacement method implemented in ANSYS.
The capability of the method is also demonstrated by transfer from a 2-D global model to a 3-D subregion model in a laminated composite plate. A laminated plate with a center hole is analyzed overall by use of a layered shell element model. A subregion around the hole is then analyzed using 3-D solid elements with nodal coupling to the layered shell elements on the subregion interface. The 3-D element model provides the well-known interlaminar stresses existing at the composite edge along the hole that are not available from the shell model.
FORFMS: A FORTRAN Simulation and Analysis Model for Flexible Manufacturing Systems
Authors: Hou Chienann , Bennett Milton 
Published: March 2021

Abstract
The flexible manufacturing system (FMS) is designed to fill the gap between high-production transfer lines and low-production NC machines by optimized utilization of tools and machines. This paper describes a general purpose simulation and analysis model, FORFMS, for the study of flexible manufacturing system. The model is PC based and programmed in FORTRAN with fixed-increment time interval mechanism. A case study of a FMS with six workstations was conducted to evaluate the system performance and to examine control strategies.
Application of CL Formula in CAM Software for Numerical Control Machining
Authors: Shen Kang-le , Yong Pan , Xuebin Liang 
Published: March 2021

Abstract
CL Formula, which was originally created in China is a unified formula for crosspoints calculation and regarded as an extension of Newton-Leibniz formula. The paper discusses the features of CL formula and its applications in NC machines. The emphasis is placed in the formula’s use in CAM applications.
Pyrolysis and Oxidative Pyrolysis of Polystyrene
Authors: Gupta Ashwani K. , Keating Eugene L. 
Published: March 2021

Abstract
Equilibrium thermochemical calculations of polystyrene are presented here under conditions of pyrolysis and oxidative pyrolysis. Oxidative pyrolysis is examined using both air and oxygen for varying moisture content in the polystyrene. The pyrolysis of polystyrene at different temperatures prior to its oxidative pyrolysis provided significantly different results. Product gas volume and flame temperature is significantly affected by the pyrolysis temperature, nature and amount of the oxidant and the amount of moisture in the waste. Results reveal significant effect of controlled combustion on the amount and nature of the chemical species formed. The results also reveal that advanced combustion process can significantly reduce the extent of post processing of gases required, and hence the size of the equipment, for achieving environmentally acceptable thermal destruction system of the solid wastes.
Computer Aided Optimization of Mechanical Systems
Authors: Seif M. A. 
Published: March 2021

Abstract
Optimization is the ultimate goal of any design that aims to obtain a maximum gain out of a system at minimum expense within a framework of physical laws that restrict an absolute multi-aspect gains. The current paper presents a design methodology for optimum performance of mechanical systems. Design optimization problems have been classified based on the nature of the relation between the parameters and the restrictions imposed by virtue of operation conditions and the complexity of weighing the competitiveness of design objectives. Three classes of optimization problems are introduced: direct (explicit), interacting (implicit), and comparative (modeling). Examples of each class are given and suggested approaches to tackle the solutions are presented. These examples cover a wide range of applications in mechanical systems and would help clarify the overall framework of problem-solution schemes frequently encountered in the design of machine components.
Frequency Analysis Tools for a First Control Course Using MATLAB
Authors: Rahnamai Kourosh 
Published: March 2021

Abstract
A set of routines is developed using the MATLAB software package to aid students in learning methods of frequency response analysis. Routines are menu driven which would require minimum knowledge of MATLAB commands. A rapid sketch of asymptotic Bode plots is emphasized which is the basis for the lead, lag, and lead-lag compensator design techniques in the first control course taught at Western New England College.
Developing and Integrating CAE Tools in Engineering Technology
Authors: Kitto Kathleen L. 
Published: March 2021

Abstract
Computer Aided Engineering (CAE) Tools are being used extensively by companies in the United States to compete in an increasingly demanding global market place. Product cycle times are being reduced while quality requirements are being increased. The students enrolled in engineering and engineering technology today will be faced with competing in these competitive markets after graduation and must acquire the skills they need for that competition before graduation. In order to help make our students more competitive in that global market place, a CAE Tools course and interdisciplinary projects are being integrated into the manufacturing, plastics and electronics engineering technology programs at Western Washington University. This paper describes the new CAE Tools course at Western and decribes specific examples of interdisciplinary projects during the past academic year.
Use of 3-D Computer Graphics Simulation in a Capstone Mechanical Engineering Design Course
Authors: Alciatore David G. 
Published: March 2021

Abstract
This paper describes three-dimensional computer graphics simulation (CGS) and how it can be applied as a useful tool in a capstone design course in Mechanical Engineering. The necessary hardware and software to perform CGS is also outlined. Three examples of senior design projects at Colorado State University which utilized 3-D CGS to help revise and verify their designs are also presented.
A General-Purpose Software for Menu Design of CAD Projects
Authors: Pao Y. C. 
Published: March 2021

Abstract
A software package MenuCAD has been developed for the general need of designing menu-driven, user-friendly CAD computer programs. The main menu is formatted similar to the major contents in the final report of the design project including Contents, Analysis, Sample Design Cases, Illustrations and Tables, References, and Program Listings. Sub-menus are further divided into items delineating the steps involved in the design. Screen help messages are provided for design of the main menu and sub-menus interactively and for applying the arrow keys on the keyboard to select a sub-menus and a particular item in the sub-menu in order to execute a desired design step. MenuCAD builds the framework, its user has to supplement with a subroutine ExecItem for describing the special features and for directing how each design step should be executed in the project. A CAD design of four-bar linkage project is presented as a sample application of this package.
Fuzzy Control of Robotic Manipulators in the Presence of Joint Friction and Load Changes
Authors: Wei Li , Bo Zhang 
Published: March 2021

Abstract
In this paper a fuzzy robot control scheme is presented which consists of a fuzzy logic (FL) controller and a conventional derivative (D) controller. The main purpose of the paper is to study the effectiveness of membership function forms of linguistic variables on achieving desired control performance. Simulations of a two-link manipulator demonstrate that the control performance in the presence of joint friction and load changes can be improved by the scheme. The proposed scheme is quite simple in structure and can be easily implemented.
A Practical Algorithm for Shortest Paths on Polyhedral Surfaces
Authors: Rambeaud P. , Zeghloul Saïd 
Published: March 2021

Abstract
This paper describes a method for treating the shortest path planning problem along a convex polyhedral surface using an unfolding process. Since most planning systems use polyhedral environments, finding the shortest possible path is very useful for some typical robotics applications such as spacecraft or submersible robot motions.
The basic idea in our algorithm is to unfold the polyhedral surface into a plane, in order to convert the 3D problem to a 2D one. We provide experimental results on a box and on a sphere to illustrate the unfolding process.
Robot Obstacle Avoidance and Path Planning in Configuration Space
Authors: Toogood R. W. , Wong Chi 
Published: March 2021

Abstract
This paper deals with the problem of planning a collision-free path for a 3 link, revolute robot among fixed obstacles within its work environment. Both the payload and the robot links are checked for collisions with the obstacles. All path planning is performed in joint or configuration space. The first part of the paper is concerned with the visualization of the complex shape of the obstacles as they appear in joint space. The second part of the paper describes and presents results of a simple path planning algorithm.
Integrated Microcomputer-LDV Instrumentation for Studying Finite Wing Aerodynamics
Authors: Khodadoust Abdollah 
Published: March 2021

Abstract
The effect of a simulated glaze ice accretion on the flow field of a three-dimensional wing is studied experimentally. A PC-based data acquisition and reduction system was used with a four-beam two-color fiber-optic laser Doppler velocimeter (LDV) to map the flow field along three spanwise cuts on the model. Results of the LDV measurements on the upper surface of the finite wing model without the simulated glaze ice accretion are presented for α = 0 degrees at Reynolds number of 1.5 million. Measurements on the centerline of the clean model compared favorably with theory.
Toward Critical Thinking Mechanical Designers
Authors: Hight Timothy K. , Hornberger Lee , Sanchez Lilia A. 
Published: March 2021

Abstract
The Mechanical Engineering Design curriculum at Santa Clara University has been reviewed using the principles of Total Quality Management. The review has led to a clear mission statement and the inclusion of an explicit component of Critical Thinking in our curriculum. We have begun to develop the educational process that will enable us to accomplish this mission.
Coupled Lateral-Torsional Vibration of a Gear-Pair System Supported by a Squeeze Film Damper
Authors: Chen Chin-Shong , Natsiavas S. , Nelson Harold D. 
Published: March 2021

Abstract
This paper investigates the coupled lateral-torsional vibration of a gear-pair system supported by a cavitated squeeze film damper (SFD). Both steady state and transient dynamic characteristics of the system are analyzed. In order to gain insight into the dynamics of the system, the free vibration frequencies and modes of the linearized system are first determined. Then, the response of the nonlinear system is examined under mass unbalance and torque excitation. The trigonometric collocation method (TCM) is employed to obtain periodic steady-state responses. Direct integration is also used in order to verify TCM and capture transient response. A comparison of the steady state responses obtained with the present model by first considering only the lateral vibration and then including torsional effects demonstrates the need to include the coupling between lateral and torsional motion. Then, the effect of parameters such as gear mesh stiffness and damping, clearance-to-diameter ratio of the SFD and gear mass unbalance on the steady state response is also presented. It is found that the mass unbalance excites not only lateral-dominated modes of the coupled system but also torsional-dominated modes. Further numerical results show that the modes of the coupled system which are dominated by lateral motion can be attenuated by using a SFD, while the modes dominated by torsional motion can be substantially suppressed by gear mesh damping. Finally, the presence of multiple solutions and complex response is predicted in some frequency ranges.
Second Order Averaging Study of an Autoparametric System
Authors: Banerjee Bappaditya , Bajaj Anil K. , Davies Patricia 
Published: March 2021

Abstract
The autoparametric vibratory system consisting of a primary spring-mass-dashpot system coupled with a damped simple pendulum serves as an useful example of two degree-of-freedom nonlinear systems that exhibit complex dynamic behavior. It exhibits 1:2 internal resonance and amplitude modulated chaos under harmonic forcing conditions. First-order averaging studies of this system using AUTO and KAOS have yielded useful information about the amplitude dynamics of this system. Response curves of the system indicate saturation and the pitchfork bifurcation sets are found to be symmetric. The period-doubling route to chaotic solutions is observed. However questions about the range of the small parameter ε (a function of the forcing amplitude) for which the solutions are valid cannot be answered by a first-order study. Some observed dynamical behavior, like saturation, may not persist when higher-order nonlinear effects are taken into account. Second-order averaging of the system, using Mathematica (Maeder, 1991; Wolfram, 1991) is undertaken to address these questions. Loss of saturation is observed in the steady-state amplitude responses. The breaking of symmetry in the various bifurcation sets becomes apparent as a consequence of ε appearing in the averaged equations. The dynamics of the system is found to be very sensitive to damping, with extremely complicated behavior arising for low values of damping. For large ε second-order averaging predicts additional Pitchfork and Hopf bifurcation points in the single-mode response.
Random and Deterministic Vibration of a SDOF System With a Set-Up Type Stiffness Characteristics
Authors: Li Youming , Noori Mohammad , Hou Zhikun 
Published: March 2021

Abstract
Random vibration analysis of a nonlinear mass-spring system with a set-up spring type characteristics is considered. This system is a model of a physical device. The motion of the mass is divided into a number of stages. Using the principle of conservation of energy, governing equation of motion for various stages of displacement of the mass are derived. Deterministic free and forced vibration responses are obtained numerically. For the random vibration the excitation at the base of the system is assumed to be Gaussian white noise. Fokker-Planck-Kulmogorov equation is then used to derive the probability density function of the displacement response for this system. Several numerical results with practical engineering applications are presented.
On the Behaviour of Steamwhirl and Nonlinear Rotor-Bearing Systems
Authors: Gómez-Mancilla Julio C. , Dimarogonas Andrew D. 
Published: March 2021

Abstract
The problem of steamwhirl is the technological limit which now prohibits the development of power generating turbomachinery substantially above 1 GW. Due to the steam flow, self excited vibrations develop at high loads, above the onset of instability of the linearized system, in the form of stable limit cycles which, at even higher loads, deteriorate to chaotic vibration.
The bearing nonlinearity is introduced in the form of high order coefficients of a Taylor expansion of the perturbation forces for fixed-arc slider bearing and employing non-linear pad functions for the tilting pad bearings. The flow excitation is introduced in the form of radial and tangential force gradients related to the flow and power generated.
The study of stable and unstable limit cycles and stability of the system in the large, beyond the linear analysis currently utilized, is done analytically for the DeLaval rotor and numerically with Finite Element analysis of typical turbomachinery rotors.
The range of loads for which limit cycles exist was found to be substantial. This is important for the operation of large machinery because such limit cycles permit the operation at loads much higher than the ones which correspond to the onset of instability of the linearized system. The conditions for the limit cycle deterioration into chaotic orbit is studied. Analytical expressions have been obtained for the different thresholds for the DeLaval rotor.
Frequency Response Characteristics of a Revolute Impact Pair
Authors: Wang Y. 
Published: March 2021

Abstract
Clearances in mechanical joints have deteriorating effects on the dynamic behavior of a machine in increasing noise and vibration and reducing the performance. In order to properly characterize these effects and to develop analytical techniques for machine design, it is necessary to investigate the dynamics associated with basic models of impacting systems. In this paper, we develop a method of harmonic balance to study a revolute impact pair. We focus on the characteristics of nonlinear frequency response of the system for a single frequency excitation. These characteristics include multiply-valued steady state response, multiple jump resonances, and existence and stability of these solutions. The effectiveness of the harmonic balance method combined with the Fast Fourier Transform technique is shown through numerical examples.
The Nonstationary Effects in Asymmetric, Angle-Ply Laminated Composite Plates
Authors: Evan-Iwanowski Ross M. , Nayfeh J. F. , Lu C. H. 
Published: March 2021

Abstract
The system in the title has been subjected to a parametric, nonstationary (NS) linear v(t) = v0 + βt, and cyclic v(t) = v0 ± γ sin βt excitations. The NS linear responses settle on the initial, constant values for extended values of the excitation frequencies, thus they stabilize the stationary (ST) response. This is true for the initial conditions taken on the stationary curve, and for different ply-angles. For the initial conditions (I.C.) beyond the ST plots, the NS responses stay also near the initial conditions, but they have the wavy forms, which increase slightly for the lower values of the forcing frequencies. For the cyclic parametric excitations, the NS responses are cyclic contained within the ranges of the excitation amplitudes ±β and (finite) response amplitudes above the ST initial values, raising up and down within these limits. It appears that they cover the whole area within the above described constraints. The decisive effect of the cyclic NS inputs, i.e., almost instantaneous cyclic responses replacing the ST responses regardless of the I.C. and ST responses, is a bench mark of the cyclic NS. This behavior is distinctly different from the NS cyclic responses of the composite columns.
Probabilistic Failure Prediction of SCS-6/Ti-15-3 MMC Ring
Authors: Holland Frederic A. , Zaretsky Erwin V. , Melis Matthew E. 
Published: March 2021

Abstract
Two-parameter Weibull analysis was used to predict the fracture strength and fatigue life of an SCS-6/Ti-15-3 MMC ring from coupon sample data. The fracture strength and fatigue life of the ring were assumed to be volume dependent. The predicted fracture strengths were determined in terms of maximum allowable ring internal pressure. Two methods were used. One simple method was to calculate an effective volume for an idealized ring on the basis of a theoretical solution approximating the stress distribution. The fracture strength and fatigue life of the coupon samples were then scaled to the effective volume of the ring. The other method utilized finite-element analysis to determine a more realistic stress distribution in the actual, geometrically imperfect ring. The total reliability of the ring was then determined by the product of the elemental reliabilities with coupon samples used as a gage. These approaches were compared with experimental fracture strength results. No fatigue data for the ring were available for comparison. Preliminary results indicate that Weibull analysis of coupon samples shows promise in predicting the fracture strength of metal-matrix composite structures.
Complimentarity Problems of Stick-Slip Vibrations
Authors: Pfeiffer Friedrich 
Published: March 2021

Abstract
Multibody systems with many friction contacts not being decoupled by some force laws afford a special treatment with respect to the uniqueness of the solution after a contact event. This problem can be solved by an optimization techniques including unequality constraints which corresponds exactly to the physical properties of stick-slip vibrations. The theoretical background to this complementarity problem is presented and illustrated by examples from machine dynamics.
Interpolated Mapping System Identification From Time Series Data
Authors: Bursal Faruk H. , Tongue Benson H. 
Published: March 2021

Abstract
In this paper, a system identification algorithm based on Interpolated Mapping (IM) that was introduced in a previous paper is generalized to the case of data stemming from arbitrary time series. The motivation for the new algorithm is the need to identify nonlinear dynamics in continuous time from discrete-time data. This approach has great generality and is applicable to problems arising in many areas of science and engineering.
In the original formulation, a map defined on a regular grid in the state space of a dynamical system was assumed to be given. For the formulation to become practically viable, however, the requirement of initial conditions being taken from such a regular grid needs to be dropped. In particular, one would like to use time series data, where the time interval between samples is identified with the mapping time step T. This paper is concerned with the resulting complications. Various options for extending the formulation are examined, and a choice is made in favor of a pre-processing algorithm for estimating the FS map based on local fits to the data set. The suggested algorithm also has smoothing properties that are desirable from the standpoint of noise reduction.