bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical Resolution of MBTI Creativity Data Into Personality Type Components
Authors: Wilde Douglass J. 
Published: March 2021

Abstract
A novel approach to the quantitative analysis of psychological issues in design is formulated. It treats any quadruple of Myers-Briggs Personality Index (MBTI) scores as a four-dimensional vector decomposable into components in the usual manner of vector analysis. To make the MBTI scores more understandable to the engineer untrained in psychology, new coordinate systems are proposed in which the component axes point toward human personality types such as “Strategist” rather than the usual idealized psychological concepts such as “Introvert”. Also presented as a semantic aid to understanding is a tentative matrix of oversimplified word labels serving as a bridge between terse psychological designators such as “INTJ” and their corresponding detailed personality type descriptions. The methods are used to analyze results from two American Society for Engineering Education (ASEE) faculty workshops on creativity in design education.
Wavelet Transforms in Fractal-Based Form Tolerancing
Authors: Srinivasan R. S. , Wood Kristin L. 
Published: March 2021

Abstract
Tolerancing is a crucial problem for mechanical designers, as it has quality and cost implications on product design. Research in tolerancing has addressed specific areas of the problem. Building upon previous research, a unified approach for geometric tolerancing with fractal-based parameters has been recently proposed. This paper explores an alternative error profile analysis and synthesis method, based on wavelets, that maintains and extends the use of fractals for surface error abstraction. An overview of the theory of wavelets is provided, and the link between fractals and wavelets is established. Experimental data are used to illustrate the application of wavelet theory to surface profile reconstruction and synthesis. The synthesis methods are then implemented in the design of ball-bearing elements, demonstrating the utility of fractal-based tolerancing. Plans for further study and implementation conclude the paper.
A Designer’s Spreadsheet
Authors: Ramaswamy Rajan , Ulrich Karl 
Published: March 2021

Abstract
We have observed that many designers use spreadsheet programs for preliminary parametric design calculations. The primary reason for this appears to be the flexibility and ease of use of spreadsheets as compared to more advanced analysis tools. However, current commercially available spreadsheets were originally designed for finance and accounting and do not naturally support the analytical techniques used in design and engineering. Attempts to adapt spreadsheets for engineering have largely been limited to adding features such as support for trigonometric functions. In this paper, we propose a fundamentally different kind of spreadsheet for use in preliminary parametric design. We describe the features of this spreadsheet that make it especially suitable for preliminary parametric design, discuss the theoretical basis for implementing it and present the results of preliminary user tests.
Measurement Foundations for Design Engineering Methods
Authors: Otto Kevin N. 
Published: March 2021

Abstract
Among the many tasks designers must perform, evaluation of concepts based on performance criteria is fundamental. A formal evaluation of a design defines a measurement of the design: an assessment reflected by real valued numbers. A measurement requires some basic a-priori information from the designer. In particular, a base-point design is required from which the remaining designs are relatively measured. Also, a metric reference design is required to compare the deviation of each remaining design from the base point design. Given these two reference designs, any other design can be evaluated numerically. Such engineering methods as concept selection charts, QFD, optimization, and many current research methods in engineering design use these measurement fundamentals to evaluate designs. Measurement theory provides a common framework to discuss solution evaluation within all of these methods. Further, the minimum formalization needed to make evaluations among design configurations is also demonstrated.
The Method of Imprecision Compared to Utility Theory for Design Selection Problems
Authors: Otto Kevin N. , Antonsson Erik K. 
Published: March 2021

Abstract
Two methods have been proposed for manipulating uncertainty reflecting designer choice: utility theory and the method of imprecision. Both methods represent this uncertainty across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. The two methods can differ, however, in the combination metrics used to combine the ranks of the incommensurate design attributes. Utility theory resolves the multi-attributes using various well proven additive metrics. In contrast, the method of imprecision resolves by also considering non-additive metrics, such as ranking by the worst case performance or by multiplicative metrics. The axioms of utility theory are appropriate for designs where it is deemed the attributes can always be traded off, even to the point of achieving zero preference in some attributes. In the case of a design with attributes which cannot have zero preference, such as stress limits or maximum allowed cost, the method of imprecision is more appropriate: it trades off attribute levels without permitting any of them to be traded off to zero performance.
Non-Intrusive Protocol Study of Design Idea Generation
Authors: Shah Jami J. , Nico Jill A. , Kraver Theodore C. 
Published: March 2021

Abstract
An experiment involving a protocol study of design idea generation is described in this paper. Two designers were used as subjects in a co-operative environment for design. This is less obtrusive to the design process than a single subject thinking out aloud. A framework for macroscopic analysis of cognitive processes in idea generation was developed. It includes identification of activity objects, generation of state diagrams, and statistical analysis of interaction densities. The role of experience and analogies in idea generation was identified and studied. Although the analysis is based on limited data, the idea of non-intrusive protocol study, and the modeling techniques developed could be used for future experiments.
Nonlinear Dynamics of an Oilless Reciprocating Compressor
Authors: Minas Constantinos 
Published: March 2021

Abstract
Two modeling methodologies of the dynamics of a motor-compressor system are presented. The first approach considered only the mechanical system subjected to a sinusoidal input force with the pressure term in the equation of motion treated as a nonlinear stiffness term. The second methodology consisted of a mathematical model that couples the electromagnetic and thermodynamic equations to the dynamic equations that describe the motion of the piston. The mathematical model which consisted of a set of four first order simultaneous nonlinear time varying differential equations, was solved by numerical integration routines that use the Adams-Moulton method with an adaptive integration step. The two methodologies are illustrated through an example. Steady-state operation was shown to be reached rapidly after a 0.13s transient. An analysis at various amplitudes and frequencies of the input voltage in the driver-coil of the motor, showed the amplitude dependence of the resonant frequency of the mechanical system, and a heavily damped system when operating at the design amplitude. The most efficient frequency of operation was also determined for a variety of required mass flow rates.
Dynamic Stability of Free Piston Stirling Engines
Authors: Ulusoy Necati , McCaughan Frances 
Published: March 2021

Abstract
A Stirling engine develops work output from a thermal input. It is a quiet pollution free engine, which can use any heat source, including solar power. The piston-displacer mechanism is essentially a vibrating spring mass system and can be dynamically modelled, leading to a set of coupled nonlinear ordinary differential equations. The inadequacies of previous linear approaches are discussed and it is shown that the inclusion of a nonlinear load will lead to stable periodic motion as desired.
Parameter Estimation Techniques Based on Optimizing Goodness-of-Fit Statistics for Structural Reliability
Authors: Starlinger Alois , Duffy Stephen F. , Palko Joseph L. 
Published: March 2021

Abstract
New methods are presented that utilize the optimization of goodness-of-fit statistics in order to estimate Weibull parameters from failure data. It is assumed that the underlying population is characterized by a three-parameter Weibull distribution. Goodness-of-fit tests are based on the empirical distribution function (EDF). The EDF is a step function, calculated using failure data, and represents an approximation of the cumulative distribution function for the underlying population. Statistics (such as the Kolmogorov-Smirnov statistic and the Anderson-Darling statistic) measure the discrepancy between the EDF and the cumulative distribution function (CDF). These statistics are minimized with respect to the three Weibull parameters. Due to nonlinearities encountered in the minimization process, Powell’s numerical optimization procedure is applied to obtain the optimum value of the EDF. Numerical examples show the applicability of these new estimation methods. The results are compared to the estimates obtained with Cooper’s nonlinear regression algorithm.
The Effect of Fiber Type on the Level of Stress Concentration Created by U-Notches in Long-Fiber Composite Plates
Authors: Turgut A. , Arsian N. , Sancaktar Erol 
Published: March 2021

Abstract
The effect of fiber type on the level of stress concentration created by u-notches were investigated for unidirectional and symmetric cross-ply laminates loaded on or off-axis. The finite element method was used for this purpose utilizing triangular elements under plane stress conditions. Analyses were performed for three different fiber reinforcements of epoxy matrix: glass, graphite and boron. Typical material properties reported in the literature for glass/epoxy, boron/epoxy and graphite/epoxy were used in calculations. The accuracy of the finite element code utilized was first checked by calculating the u-notch stress concentration factors for an isotropic steel plate.
MMC Life System Development (Phase I): A NASA/Pratt & Whitney Cooperative Program
Authors: Zaretsky Erwin V. , deLaneuville Robert E. 
Published: March 2021

Abstract
Pratt & Whitney Aircraft and NASA Lewis Research Center studied a silicon-carbide-fiber-reinforced, titanium-metal-matrix (MMC) composite designated SiC(SCS-6)/Ti-15V-3Cr-3Al-3Sn. Fracture tests of three nominal 15.24-cm (6-in.) diameter SCS–6/Ti-15-3 rings at 427 °C (800 °F) and room temperature resulted in failure at internal pressures of 0.172 GPa (25 ksi) (average) and 0.235 GPa (34.1 ksi), respectively. Predictions of internal pressure to failure varied from 0.140 to 0.276 GPa (20.3 to 40.1 ksi) at 427 °C (800 °F). Nondestructive evaluation revealed that the rings’ MMC cores had varying density and were not uniformly distributed inside the monolithic casing. Analytical predictions of ring cyclic life at 0.154-GPa (22.4-ksi) internal pressure varied from 1000 to 15 000 cycles. No fatigue life data were obtained with the MMC rings for comparison with theory.
A Life Prediction Method for Matrix Dominated Fatigue Failures of SCS-6/Ti-15-3 MMC
Authors: Gravett Phillip W. 
Published: March 2021

Abstract
This paper presents a method for determining the matrix dominated cyclic fatigue capability of continuous fiber reinforced SCS-6, Ti-15-3 metal matrix composites (MMC). The basis of the fatigue life prediction system relies on the matrix material dominating the fatigue behavior of the MMC. This assumption has been supported by test data and failure mechanisms identified in unidirectional isothermal and out-of-phase thermomechanical fatigue (TMF) specimens which typically show an area of matrix cracking before failure. Since the matrix fatigue capabilities dominate the fatigue behavior of the composite, an MMC thick cylinder model with an anisotropic coefficient of thermal expansion is used to characterize the state of stress in the matrix. The Smith-Watson-Topper fatigue stress damage parameter is applied to the calculated matrix stresses to determine a “corrected” matrix fatigue stress which is isolated from laminate geometry and laminate stress. This method correlates well to room and high temperature SCS-6/Ti-15-3 MMC test data. Since the “corrected” matrix stress fatigue response is independent of fiber volume, stress ratio, and load history, this MMC Life Prediction System can be used to predict the fatigue behavior of any reasonable laminate and loading in which the failure is matrix dominated. With this life system, life analyses can be performed for laminate geometries and loadings at which no test data exists, which will prove valuable when designing engine components where optimization of MMC capabilities are required but testing is limited.
Elastic Plastic Analysis of Bimaterial Beams With Strain Hardening
Authors: Eischen J. W. , Reagan S. W. 
Published: March 2021

Abstract
Considerable attention has been paid to the bimaterial thermostat stress analysis problem as regards applications in microelectronic packaging. When a bimaterial beam is subjected to a temperature change, internal stress is developed that generates curvature. The present paper generalizes previous idealizations whereby a linear elastic material response has been assumed. We treat each of the beam materials as elastic-plastic with a bilinear response. A solution is obtained for the stress and deformation in the bimaterial structure following a “strength of materials” approach. While the solution is imperfect in that the stress free boundary conditions at the ends of the strip are not satisfied exactly, it does capture the overall behavior of the bimaterial beam but for the well-known end effect. Several numerical examples are presented using design data for materials commonly encountered in microelectronics applications.
Response Analysis of Discretized Plates Under In-Plane and External Nonstationary Random Excitations
Authors: To C. W. S. , Wang B. 
Published: March 2021

Abstract
Responses of panel structures on board ships and aerospace systems under point and in-plane intensive transient excitations, originating, primarily, from near-mixed explosion and impact upon the ships are investigated and presented in this paper. The panel structures are idealized by finite elements while the intensive transient in-plane and point loads are modelled as nonstationary random processes. The latter are treated as products of modulating functions and Gaussian white noise processes. The focus of the paper is the comparison of results obtained by employing the three nodes, eighteen degree-of-freedoms (DOF) triangular bending plate element (the explicit element stiffness, mass and stability matrices of which have been derived by the authors) and the four nodes, twelve DOF Melosh-Zienkiewicz-Cheung (MZC) rectangular bending plate element. The isssues addressed are: (a) convergence and reduction of computational time by applying the eighteen DOF plate element in comparison to the MZC element, (b) the contribution of the in-plane nonstationary random excitation on the response of the discretized structures, and (c) the influence of the number of modes included in the response computation.
Nonstationary Vibrations of a String With Time-Varying Length and a Mass-Spring System Attached at the Lower End
Authors: Terumichi Y. , Ohtsuka M. , Fukawa Y. , Yoshizawa M. , Tsujioka Y. 
Published: March 2021

Abstract
The purpose of this paper is to study the nonstationary vibrations of a string with time-varying length, and a mass-spring system attached at the lower end. The string is excited sinusoidally by the horizontal displacement at its upper end and the mass-spring system has two-degrees-of-freedom vertically and horizontally. It is clarified analytically that the moving velocity of the string influences the peak amplitude of the string vibration at the passage through resonances. Moreover it is shown numerically that the amplitudes of both the string and the mass vibrations depend on the sign of the moving velocity, in the case where the natural frequency of the mass-spring system is close to the frequency of the excitation. The above two theoretical results are confirmed experimentally with a simple experimental setup.
Parametric Stability of Belt-Driven Slider-Crank Mechanisms With Flexible Coupler
Authors: Chivate Pramod N. , Farhang Kambiz 
Published: March 2021

Abstract
Two mathematical models are presented for investigating parametric vibration stability of high-speed slider-crank mechanisms. Both models account for flexibility in the connecting rod and the drive system. The drive system is assumed to comprise a motor, pulleys and flexible drive belt. A combination of Newtonian and Lagrangian formulations is used to derive a system of nonlinear partial differential equations with position-periodic coefficients. Applying Galerkin’s method and performing appropriate linearizations, these equations are reduced to a system of linear ordinary differential equations with position-periodic coefficients.
The above two formulations are employed along with the Floquet theory to investigate parametric stability of slider-crank mechanisms with flexible connecting rod and drive system.
Nonconservative Stability of Gyroscopic Rotor Systems
Authors: Chen Hwang-Kuen , Ku Der-Ming , Chen Lien-Wen 
Published: March 2021

Abstract
The stability behavior of a cantilevered shaft, rotating at a constant speed and subjected to a follower force at the free end, is studied by the finite element method. The equations of motion for such a gyroscopic system are formulated by using deformation shape functions developed from Timoshenko beam theory. The effects of translational and rotatory inertia, gyroscopic moments, bending and shear deformations are included. In order to determine the critical load of the present nonconservative system more quickly and efficiently, a simple and direct method that utilizes the eigenvalue sensitivity with respect to the follower force is introduced. The numerical results show that for the present nonconservative system, the onset of flutter instability occurs when the first and second backward whirl speeds are coincident. And also, due to the effect of the gyroscopic moments, the critical flutter load decreases as the rotational speed increases.
Analysis of Nonlinear Oscillators by Wavelet Transform Lyapunov Exponents
Authors: Lamarque C.-H. , Malasoma J.-M. 
Published: March 2021

Abstract
In this paper we give the definition of exponents which look like to Lyapunov exponents in the cases of non-smooth flows of differential equations or iterated maps, and carry back Lyapunov exponents in smooth cases. We test our definition by using some simple examples examples.
Analytical Prediction of Nonlinear System Response to Non-Stationary Excitations
Authors: Raman Arvind , Davies Patricia , Bajaj Anil K. 
Published: March 2021

Abstract
The study of the non-stationary response of systems has many applications in problems related to transition through resonance in rotating machinery, aerospace structures and other physical systems.
In this paper, we present methods to analytically predict the response of some weakly nonlinear systems to slowly varying parameter changes. We consider systems which can be averaged and represented as two first order equations. The evolution of the solutions of such systems through critical (jump or bifurcation) points is studied using the method of matched asymptotic expansions. As an example, the method is used to predict the response of the forced Duffing’s oscillator during passage through resonance.
Starting with a general system of two, first-order equations, we set up a slowly varying equilibrium or ‘outer’ solution as an asymptotic expansion about the stationary solution. This solution is seen to be invalid in a small neighborhood of the critical points — the ‘inner’ region. In this inner layer, the system of equations is transformed into the Jordan canonical form, which is easier to study. Using approximations from the center manifold theory, the problem is reduced to one first-order equation. By making appropriate scale changes, an ‘inner’ solution is developed. This solution is asymptotically matched with the outer expansion to yield a unified solution valid for all time.
Dynamic Responses of Plates With Viscoelastic Damping Treatment
Authors: Yi Sung , Ahmad M. Fouad , Hilton Harry H. 
Published: March 2021

Abstract
Dynamic transient responses of plates with free damping layers are studied in order to evaluate free layer damping treatment performances. The effects of forcing frequencies and temperatures on free-layer viscoelastic damping treatment of plates are investigated analytically. Young’s modulus ratio of structures to viscoelastic damping materials and the damping layer thickness effects on the damping ability are also explored.
A Comparison of Continuum and Lumped-Mass Models for Hyper-Redundant Manipulator Mechanics
Authors: Chirikjian Gregory S. 
Published: March 2021

Abstract
The most efficient methods for representing dynamics in the literature require serial computations which are proportional to the number of manipulator degrees-of-freedom. Furthermore, these methods are not fully parallelizable. For ‘hyper-redundant’ manipulators, which may have tens, hundreds, or thousands of actuators, these formulations preclude real time implementation. This paper therefore looks at the mechanics of hyper-redundant manipulators from the point of view of an approximation to an ‘infinite degree-of-freedom’ (or continuum) problem. The dynamics for this infinite dimensional case is developed. The approximate dynamics of actual hyper-redundant manipulators is then reduced to a problem which is O(1) in the number of serial computations, i.e., the algorithm is O(n) in the total number of computations, but these computations are completely parallelizable. This is achieved by ‘projecting’ the dynamics of the continuum model onto the actual robotic structure. The results are compared with a lumped mass model of a particular hyper-redundant manipulator. It is found that the continuum model can be used to generate joint torques to within ten percent of values computed from the lumped mass model.
Impact Control of Flexible Robots Using Sliding Mode Technique
Authors: Chen Eming 
Published: March 2021

Abstract
In the flexible robot force control situations, if there exists a discontinuity between the robot tip sensor and the work-piece, the robot contact process becomes a nonlinear system control problem. The control tasks require the robot hand to switch from free motion control to contact motion control. The inevitable high impact force tends to let the system become unstable. The purpose of this paper is to investigate the control of the manipulator during this process. In this paper, dynamic models of the flexible link manipulator in both non-contacted and contacted modes are first derived. Due to the fact that the arm vibration shape functions are changed between the two modes, a transform matrix will be used to transform the controlled state variables, such as generalized position and velocity. A nonlinear sliding mode control technique has been implemented in an attempt to extinguish the chatter phenomenon and settle quickly to the desired setpoint.