bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vibration of Roller Chain Drives at Low, Medium and High Operating Speeds
Authors: Choi Woosuk , Johnson Glen E. 
Published: March 2021

Abstract
A model based on axially moving material is developed to study transverse vibration in roller chain drives. A unique feature of the work presented in this study is that impact, polygonal action and external periodic load have been included through chain tension and boundary conditions and periodic length change is also considered. The impact between the engaging roller and sprocket surface is modeled as a single impact between two elastic bodies and the modeling of the polygonal action is based on a four bar mechanism (rigid four bar at low speeds, elastic four bar at moderate and high speeds). At low and medium operating speeds, the system equation of motion for the chain span is expressed as a mixed type partial differential equation with time-dependent coefficients and time-dependent boundary conditions. At high operating speeds, the system equations of motion are two partial differential equations for transverse and longitudinal vibrations respectively and they are nonlinearly coupled The effects on transverse vibration of center distance, the moment of inertia of the driven sprocket system, static tension, and external periodic load are presented and discussed. Solutions are obtained by a finite difference method and Galerkin’s method.
An Experimental and Theoretical Study of Dynamic Structural Stiffness in Compliant Foil Bearings
Authors: Ku C.-P. Roger 
Published: March 2021

Abstract
This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil bearings. This study provided the first opportunity to quantify the dynamic structural stiffness of bump foil strips for a wide range of operating conditions. The experimental data were compared to results obtained by a theoretical model developed earlier, and the comparisons show very good agreement. The effects of bearing design parameters, such as static loads, dynamic displacement amplitudes, bump configurations, pivot locations, surface coatings, and lubricant were also evaluated. An understanding of the dynamic characteristics of bump foil strips resulting from this work offers designers a means for enhancing the design of high-performance compliant foil bearings.
Passive Control of Vortex Shedding Induced Vibration of a Five-Hole Probe
Authors: Kimerer Neil B. 
Published: March 2021

Abstract
Vortex shedding in flow over a five-hole probe, used to measure three dimensional flow, excites the probe into vibration which causes measurement errors and acoustically induced structural fatigue of the probe stem. One method of reducing the coherent structure of the shed vortices and thereby reduce the vibration is to place a fin on the probe shaft with the fin free to rotate around the shaft. In a particular five-hole probe application there was no room for a fin so an alternate method of breaking up the coherent structure in the vortices was required. Coiling a wire around the probe was a technique tried using several wire diameters and coil spacings. Vibration levels were measured and analyzed for several wire coil configurations and compared to the vibration reduction achieved by the fin.
Method for Determining System Eigenvalues From FRF for Noise Contaminated Subsystems
Authors: Chen H. C. , Lee Eric K. , Tsuei Y. G. 
Published: March 2021

Abstract
A method for determining the eigenvalues of a synthesized system from the Frequency Response Function (FRF) for noise contaminated subsystems is presented. This method first uses matrix Auto-Regressive Moving-Average (ARMA) model in the Laplace domain to describe each subsystem. Then a modal force method by ARMA model can be established. Only the FRF at the connecting joints is needed in the analysis to form a matrix named Modal Force Matrix. From this matrix, both synthesized system modes and substructure modes can be extracted simultaneously. Since the inverse operation is not required to form Modal Force Matrix, the computation is reduced drastically. The eigensolution of the system in any frequency range can be determined independently. Numerical study suggests that good results can be achieved by this method.
Longitudinal Impact of a Rectilinear Elastic Link in Kinematics Chains
Authors: Marghitu Dan B. , Hurmuzlu Yildirim 
Published: March 2021

Abstract
In this article we consider the longitudinal impact of a rectilinear elastic link against a solid using Hertz contact theory. The main objective is to develop an analytical model that incorporates the effect of the general motion on the vibration of elastic elements in kinematic mechanisms. Equations for the translational and rotational motions of the link are developed by applying Hamilton’s principle. Kinetic energy that is required for the application of this principle has been derived by utilizing a generalized velocity field theory for elastic solids. This approach provides means to include the inertia terms directly in the equations of motion. Effects such as centrifugal stiffening and vibrations induced by Coriolis forces are accommodated automatically, rather than with the aid of ad hoc provisions. With the Dirac delta function defined as the limit of a sequence of functions we solve the discontinuities due to the impact.
Crack Detection in Composite Driving Shafts by Experimental Modal Analysis
Authors: Irretier H. 
Published: March 2021

Abstract
A case study is presented in which a composite driving shaft of a motor-bike was loaded with different increasing numbers of load-cycles in a pulsating testing machine to reach different stages of damage. For each number of load-cycles an experimental modal analysis was performed by an iterative, global, multi-degree-of-freedom, frequency-domain modal testing technique and the eigenfrequencies and modal damping ratios were identified. From the results it is shown that the damping increases with the number of load-cycles i.e. the state of damage. However, it turned out that a more sensitive indicator for the state of damage is the splitting and shifting of the ‘double’ eigenfrequencies of the bending modes of the driving shaft with the ‘axisymmetric’ circular ring cross section. This fact is shown on the basis of several related experimental data.
Singularity of Constraint Mechanical Systems
Authors: Wang J. Y. , Wu J. K. 
Published: March 2021

Abstract
The solution set of nonlinear kinematic constraint equations can be divided into regular and critical solution subsets, according to linear dependency of gradient vectors of the constraint equations. However, relative to a given input coordinate set, the solution set can also be separated into singular and nonsingular solution subsets, according to whether the sub-Jacobian matrix with respect to the output and intermediate coordinates is rank deficient or not. By providing precise definitions and classifications of singular configurations, from both mathematical and physical points of view, a better understanding of the kinematic behavior of singularity is obtained. Moreover, by extending the definition of the singular solution set to the output space and exploring the mathematical meaning of it, the difficulty in formulating mathematical expressions for workspace problems is resolved.
On the Derivation of Nonlinear and Linearized Models of Flexible Bodies in Large Global Motion
Authors: Lee Jung-Hwan , Uicker John J. 
Published: March 2021

Abstract
This paper presents a systematic modeling technique for systems of flexible bodies in large global motion. 4 × 4 homogeneous coordinate transformation matrices are used together with the Finite Element Method. By using homogeneous coordinates, derivatives of the transformation matrices can be represented by differential operator matrices. Due to this fact, one can derive the equations of motion in explicit matrix form. In this paper, the derivation of the general linearized as well as the nonlinear equations of motion are presented. Two typical mechanisms are chosen to show the validity of the procedures. Time history analysis and frequency domain analysis have been done using the mechanism models. The modal time integration technique has been applied to show the validity of the linearized equations of motion. The eigenvalues and eigenvectors of the mechanisms are used for the time integration of the linearized equations. For the frequency domain analysis, plots of changes in natural frequencies of the mechanisms are shown. These results show not only the dynamic properties of the structural parts of mechanism, but also those of the rigid body motions of the mechanism.
Application of Concurrent Engineering to Hi-Tech Product Realization
Authors: Pratt Michael K. , Deutsch Patricia B. 
Published: March 2021

Abstract
Since 1986, when the Institute for Defense Analysis first coined the term “concurrent engineering” (Carter and Baker, 1991), there has been much talked about and written on the subject. Early treatments of this subject focused principally on increasing the synergy between product development and manufacturing process development. Today’s increasing time-to-market pressures force the extension of the scope of this concurrent strategy to include all processes, such as customer training, documentation, and installation and field support, required to launch a new product successfully in a competitive industry.
Even with this larger scope, the competitive advantages of a concurrent strategy are well proven (Vesey, 1991) (Port et al, 1990) — there is no need for additional motivation. Hence, this paper addresses a specific strategy for implementing concurrent engineering in the real world. The context for this subject is the experiences on a large development project at DSC Communications Corporation, addressing the following: 1) the situation at the onset of the project, 2) what was done to implement concurrent engineering, and 3) the results of having committed to concurrent engineering. The final section offers some experience-based advice in terms of critical success factors.
Suspension Design Optimization of a Washing Machine: Part I — Modeling and Validation Results
Authors: Türkay O. S. , Tuğcu A. K. , Sümer I. T. , Kiray B. 
Published: March 2021

Abstract
The development of a non-linear time invariant rigid body dynamic model and the experimental validation of the suspension system of a horizontal-axis washing machine has been discussed in previous works by the authors. In this paper (Part I), modeling and experimental validation of a different suspension configuration of a test washing machine is assessed. The simulation model predicts the transient and steady-state vertical and horizontal amplitudes within maximum errors of 10% and 14%, respectively. The results are consistent with the results of the previous work. Thus, the simulation software code is verified for a generalized suspension design optimization of horizontal-axis washing machines.
In a companion paper (Part II), various formulations are discussed to select an objective function for parametric suspension design optimization and a parametric grid optimization method is implemented to the test washing machine introduced in this paper.
Application of an Information-Based Design for Assembly Theory to Assembly Workstation Design
Authors: Hunt David O. , Sturges Robert H. 
Published: March 2021

Abstract
An effective presentation of components at the workstation can have a significant impact in reducing assembly time. Our goal is to reduce the assembly time by optimization of the component presentation. The assembly factors recognized in Design for Assembly theory as relevant to both parts acquisition and assembly workstation layout are recognition, orientation, weight, and handling distance. This study considers a single manual assembler at an assembly station, with the components in rectangular bins of differing sizes and aspect ratios. Ninety degree rotations are allowed for minimizing potential handling distance. The assembly task is modelled with multiple assembly points representing the final location of the components. Components can be preoriented or random in the bins, with preorientation removing the recognition and orientation time penalties. The problem formulation employs Mixed Integer Non-Linear Programming (MINLP), and numerical evidence suggests an np-hard problem. Heuristic methods control computational time to practical levels for realistic assembly tasks. Our results show that numerical optimization of assembly workstation layout can reduce the expected level of difficulty over random or manual workstation design methods.
A Knowledge-Based Engineering System for the Design of Injection Molded Plastic Parts
Authors: Pratt S. D. , Sivakumar M. , Manoochehri S. 
Published: March 2021

Abstract
This study presents a knowledge-based engineering system for the design of injection molded plastic parts which is built around a commercial object-oriented design language. Knowledge-based engineering is an implementation paradigm in which the knowledge about the part is stored along with its geometry and the knowledge is used to verify the manufacturability and processability of the part. This system enables the designer to represent the plastic part in terms of hybrid features which associate product and process knowledge with part geometry. Engineering rules about part moldability and strength, process and material considerations, and mold design are captured in the system. To illustrate the capability and application of the system to real-world problems, the design of an enclosure for a portable data entry device is pursued. This exercise demonstrates the effectiveness and robustness of the system which applied appropriate rules at different stages of design to make the part inherently moldable.
Theoretical Analysis of Link Length Errors in Large Guided Chain Systems
Authors: Jin Y. , Carpino M. 
Published: March 2021

Abstract
Large guided chains are often used in manufacturing machinery to move materials and tooling. In such applications, the accuracy of the motion of the chain has a significant impact on the quality and yield of the process. The motion of the chain will be dependent on the geometry of the machine, the dynamic parameters of the machine, and the exact tolerances of the machine components. The research presented in this paper will first address the kinematics of a chain system. The analysis will include both chordal effects and link length variations, which affect the engagement between the chain and the drive sprocket. Second, the kinematic analysis will be used to develop a dynamic analysis based upon Lagrange’s equations for a chain system with variable link lengths. Results are presented which demonstrate the influence of chain mass and drive stiffness on the dynamic behavior of the system operating at both low and high speeds with oversized links.
Reliability-Based Optimal Design of a Bistable Compliant Mechanism
Authors: Howell L. L. , Rao S. S. , Midha A. 
Published: March 2021

Abstract
Compliant mechanisms obtain at least some of their motion from the deflection of their flexible members. Advantages of such mechanisms include the reduction of manufacturing and assembly cost and time. Bistable mechanisms are particularly useful in applications where two stable equilibrium positions are required, such as switches, gates, and closures. Fatigue is a major concern in many compliant mechanisms due to the cyclic stresses induced on the flexible members. In this paper, a method for the probabilistic design of a bistable compliant slider-crank mechanism is proposed. Link lengths, material properties, and cross-section dimensions are taken as random variables. Probabilistic constraints on the maximum and minimum required input torque, location of stable equilibrium position, and overall size are included. The objective function is the maximization of the mechanism reliability in fatigue. Several design studies are performed to gain further insight into the nature of the problem.
Component Selection Using Genetic Algorithms
Authors: Carlson Susan E. , Ingrim Michael , Shonkwiler Ronald 
Published: March 2021

Abstract
Genetic algorithms are investigated for use in obtaining optimal component configurations in dynamic engineering systems. Given a system layout, a database of component information from manufacturers’ catalogs, and a design specification, genetic algorithms are used to successfully select an optimal set of components. Five different algorithms are investigated for use on an hydraulic example. The algorithms are compared on the basis of expected hitting lime: the number of system simulations required to find the solution. One algorithm is found to have the best set of characteristics for solving component selection problems.
Design of Planar 3-R Robotic Workcells in Two-Space With Rotation at the Third Joint Limited to Exactly One Turn
Authors: Soman N. A. , Davidson Joseph K. 
Published: March 2021

Abstract
An interactive graphics-based computer scheme was developed that determines suitable locations for a workpiece, and its associated task-motion, in the dexterous workspace of a three-hinged planar robotic workcell. It determines all acceptable positions for the first joint of the robot relative to the workpiece; therefore, all solutions are represented as an area in two dimensions, unlike existing methods of motion-planning that present them as a volume in a three-dimensional joint-space for the same planar robot. This simplifies the solution-space by reducing its dimension from three to two. The method differentiates between the constraints that singular configurations, workspace boundaries, the excursion-range of one full turn at the third rotary joint, and physical obstacles impose on the design of a planar robotic workcell, thus giving a better understanding of the global properties and physical limitations of the workcell. All possible acceptable designs appear in a graphical form that can be readily visualized and be directly measured in a Cartesian frame of reference in the workcell. The method can be applied to either open or closed motion trajectories. Applications include the design of robotic workcells that are used for fusion welding and for deposition of adhesives, where, in each case, the attitude of the end-effector is as important to the task as is the path that a point on the tool follows.
Data Localization Algorithms for Automated Inspection
Authors: Choi Woncheol , Kurfess Thomas R. 
Published: March 2021

Abstract
For automated inspection, correlating measured data with original design geometry and tolerance specification is of fundamental necessity. In order to compare measured data to nominal geometry, it is necessary to find an exact location of the measured points with respect to a nominal geometry coordinate system. If a tolerance zone is provided, its boundaries must be compared to the measured points to determine the quality and functionality of the part. The problem of localizing measured data can be formalized as an unconstrained optimization problems. In this paper, we develop the localization algorithms using the least square criterion. Such a localization algorithm can also place the measured data into tolerance zone, when it is specified.
Notes on Interpreting Monotonicity Analysis Using Karush-Kuhn-Tucker Conditions and MONO: A Logic Program for Monotonicity Analysis
Authors: Hsu Yeh-Liang 
Published: March 2021

Abstract
The Monotonicity Principles are only necessary conditions. All principles are under the condition “if the problem is well constrained”. But one of the important purposes of Monotonicity Analysis is to identify optimization models that are not well constrained. Before applying Monotonicity Principles to a problem, whether the problem is well constrained is not known. This paper attempts to clarify some potential problems of Monotonicity Analysis when applying to not-well-constrained problems. These problems can be easily explained using the Karush-Kuhn-Tucker optimality conditions. Ways to prevent the users from reaching erroneous results in these situations are proposed. These results are implemented in the computer program MONO. MONO is a logic program which automatically generates rigorous Monotonicity Analysis steps and global facts about the optimization model. Hardware and software requirements of this program are minimal. A hydraulic cylinder design example is used to demonstrate the program.
Hybrid Feature Extraction for Machining Applications
Authors: Fields Malcolm C. , Anderson D. C. 
Published: March 2021

Abstract
A hybrid feature extraction algorithm for extracting cavity features for machining applications is presented. The algorithm operates on both a feature-based solid model of a part and its corresponding boundary representation solid model. Information available from both part representations is used, offering a more robust and efficient solution for some of the critical limitations of current feature extraction algorithms, such as verification of completeness, computation of cavity volumes, and maintenance of design information.
The hybrid feature extraction algorithm combines the strengths of feature-based design and feature extraction approaches to linking design and manufacturing. Starting with a feature-based model of a part consisting of volumetric design features combined with a stock shape using set operations, the algorithm transforms this model into a feature model containing only machinable cavity features. The transformation involves computations on both the set theoretic feature model and its corresponding boundary representation solid model, and deals with the complexities of feature-feature intersections and protrusions. By combining the higher-level product information contained in the design feature model with the topological and geometric information in the boundary representation model, the algorithm supplements traditional boundary representation extraction with non-geometric product information, enabling the verification of completeness, and significantly aiding the computation of the appropriate feature volumes.
Computing Equidistant Curves and Surfaces
Authors: Sarma R. , Dutta D. 
Published: March 2021

Abstract
The problem of computing equidistant curves and surfaces between a point and (i) a parametric curve and (ii) a parametric surface is considered. This problem is important since it can form a basis for further generalizations of the problem, viz., computing equidistant curves and surfaces between a pair of curves and a pair of surfaces. Engineering applications of such equidistant curves and surfaces include fluid flow analysis, mesh generation and shape interrogation.
Representation of Relative Freedom Derived From Geometric Models
Authors: Laowattana Schitt , Sturges Robert H. 
Published: March 2021

Abstract
Multi-contact constraints representing the assembled state of polygonal solid objects can be represented by screw systems which provide a complete description of rotational and translational freedom. In most cases, the computation of relative freedom does not require consideration of all constraints. We have developed an algorithm to identify redundant constraints, therefore minimizing the complexity of assembly/disassembly planning. We also employ the method to determine relative stability which identifies unstable configurations of assembled parts.