bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subset Selection Methods for Design Sensitivity Analysis of Constrained Dynamic Systems
Authors: Twu Jun-Tien , Krishnaswami Prakash , Rampalli Rajiv 
Published: April 2021

Abstract
In the Lagrangian formulation of the constrained motion of mechanical systems, a system of Differential-Algebraic Equations is generally encountered. The popular Backward Differentiation Formula for the numerical solution of such problems leads to an over-determined system of equations. The correct choice of a proper exactly determined subset can greatly enhance the performance of a solution algorithm. In this paper, we discuss four solution methods with different choices of subsets. Three numerical examples are solved to compare the accuracy and efficiency of these methods.
Sensitivity Analysis for the Steady-State Response of Damped Linear Elastodynamic Systems Subject to Periodic Loads
Authors: Tortorelli Daniel A. 
Published: April 2021

Abstract
Adjoint and direct differentiation methods are used to formulate design sensitivities for the steady-state response of damped linear elastodynamic systems that are subject to periodic loads. Variations of a general response functional are expressed in explicit form with respect to design field perturbations. Modal analysis techniques which uncouple the equations of motion are used to perform the analyses. In this way, it is possible to obtain closed form relations for the sensitivity expressions. This eliminates the need to evaluate the adjoint response and psuedo response (these responses are associated with the adjoint and direct differentiation sensitivity problems) over the time domain. The sensitivities need not be numerically integrated over time, thus they are quickly computed. The methodology is valid for problems with proportional as well as non-proportional damping. In an example problem, sensitivities of steady-state vibration amplitude of a crankshaft subject to engine firing loads are evaluated with respect to the stiffness, inertial, and damping parameters which define the shaft. Both the adjoint and direct differentiation methods are used to compute the sensitivities. Finite difference sensitivity approximations are also calculated to validate the explicit sensitivity results.
Multi-Body Impact Motion With Friction: Analysis, Simulation, and Experimental Validation
Authors: Han Inhwan , Gilmore B. J. 
Published: April 2021

Abstract
When a multi-body system collides with a single body or with another multi-body system, impact dynamics with friction should be considered. This paper presents a general computer oriented analysis of impact dynamics incorporating friction. The presence of friction between sliding contacts during the impact makes the problem difficult since the events such as reverse sliding or sticking, which may occur at different times throughout the impact, must be determined. The boundary representations of the bodies are used to solve for the velocities at the points of contact. Using this information and a classification of the modes of impact, the frictional impact with sliding contact problem is solved. Using a high speed video camera, the resulting computer strategy is experimentally verified. Simulation and experimental results agree.
Recursive Linearization of Multibody Dynamics and Application to Control Design
Authors: Lin Tsung-Chieh , Yae K. Harold 
Published: April 2021

Abstract
The non-linear equations of motion in multi-body dynamics pose a difficult problem in linear control design. It is therefore desirable to have linearization capability in conjunction with a general-purpose multibody dynamics modeling technique. A new computational method for linearization is obtained by applying a series of first-order analytical approximations to the recursive kinematic relationships. The method has proved to be computationally more efficient. It has also turned out to be more accurate because the analytical perturbation requires matrix and vector operations by circumventing numerical differentiation and other associated numerical operations that may accumulate computational error.
Kinematic Study of the Face Gear
Authors: Chen Yih-Jen Dennis 
Published: April 2021

Abstract
This paper presents the kinematic study of the face gear drive system. The study includes three different configurations which are: (1) the on-center orthogonal face gear drive, (2) the on-center non-orthogonal face gear drive, and (3) the offset orthogonal face gear drive. The mathematical description for the gear meshing and the resulting face gear tooth surface is developed. This paper also presents the criteria for detecting the limitation of the effective face width due to tooth pointing and undercutting. The technique presented is applied to develop a computer program. This design automation tool allows visualizing the gear meshing and tooth geometry of the face gear drive.
Analysis and Synthesis of Mechanical Error in Universal Joints
Authors: Cagney J. L. , Rao S. S. 
Published: April 2021

Abstract
The modeling of manufacturing errors in mechanisms is a significant task to validate practical designs. The use of probability distributions for errors can simulate manufacturing variations and real world operations. This paper presents the mechanical error analysis of universal joint drivelines. Each error is simulated using a probability distribution, i.e., a design of the mechanism is created by assigning random values to the errors. Each design is then evaluated by comparing the output error with a limiting value and the reliability of the universal joint is estimated. For this, the design is considered a failure whenever the output error exceeds the specified limit. In addition, the problem of synthesis, which involves the allocation of tolerances (errors) for minimum manufacturing cost without violating a specified accuracy requirement of the output, is also considered. Three probability distributions — normal, Weibull and beta distributions — were used to simulate the random values of the errors. The similarity of the results given by the three distributions suggests that the use of normal distribution would be acceptable for modeling the tolerances in most cases.
Optimal Design of the Path of Chain Link Systems
Authors: Peng J.-P. , Carpino M. 
Published: April 2021

Abstract
A general method for the design of the optimal chain path for a chain link system is presented. The dynamics of a chain link system are affected by both the kinematic effects of finite sized links and dynamic effects. Both of these effects have been incorporated into a dynamic model for arbitrary chain paths. This model is then used to determine chain paths which have been optimized for minimum position error and speed variation. Results of the dynamic analysis are presented for both low speed and high speed operations. An example of an optimized chain path for an oval configuration operating at low speed is also presented.
A Recursive Dynamic Formulation for Flexible Mechanisms
Authors: Souh Byung Yil , Kim S. S. 
Published: April 2021

Abstract
This paper presents a recursive dynamic formulation for modeling and simulation of spatial mechanisms with elastic beams. In order to circumvent some difficulties in the convential assumed mode approach, each flexible link is modeled with finite elements. The motion of the flexible link comprises the rigid body motion and elastic deformation. The elastic deformations are represented by nodal coordinates relative to the moving coordinate system fixed to the link. Recursive kinematic relationships are derived between finite beam elements. Using variational equations of motion for the one beam element and recursive relationships, the equations of motion for the open-chain flexible bodies are derived in terms of relative joint and nodal coordinates. For closed-loop systems, Lagrange multipliers are used to generate the equations of motion with kinematic constraints. The proposed method models geometric nonlinear effects and axial tensioning effects automatically. Also, the difficulties of the mode selection in the assumed mode approach is avoided. Numerical examples illustrate the effectiveness of this approach.
Efficient Dynamic Computer Simulation of Simple-Closed Spatial Linkages
Authors: Wang L. T. 
Published: April 2021

Abstract
A new method of formulating the generalized equations of motion for simple-closed (single loop) spatial linkages is presented in this paper. This method is based on the generalized principle of D’Alembert and the use of the transformation Jacobian matrices. The number of the differential equations of motion is minimized by performing the method of generalized coordinate partitioning in the joint space. Based on this formulation, a computational algorithm for computer simulation the dynamic motions of the linkage is developed, this algorithm is not only numerically stable but also fully exploits the efficient recursive computational schemes developed earlier for open kinematic chains. Two numerical examples are presented to demonstrate the stability and efficiency of the algorithm.
A Stress Based Methodology for the Design of Wire Rope Systems
Authors: Velinsky Steven A. 
Published: April 2021

Abstract
Wire ropes have been used extensively in a wide variety of applications for many years. However, detailed analysis capabilities for wire ropes have only been developed in the several years. Furthermore, these capabilities have not been exploited in the design of actual systems which are still designed in an empirical manner. This paper presents a stress based design methodology for wire rope systems based on these recent analysis capabilities. In addition to wire stress, this methodology allows multiple system properties to be considered during the design process. This is in opposition to current methods which only consider rope strength, and then size other components to match that particular rope. The optimum design problem is formulated for minimum weight design. Finally, examples illustrate the usefulness of the approach and its applicability to the improved design of real systems.
A Simplified Approach for Design Under Variable Amplitude Fatigue Loads
Authors: El-Sayed Mohamed E. M. 
Published: April 2021

Abstract
This paper presents an approach to simplify the design process for fatigue life requirement, when dealing with variable amplitude load history. The basic concept is to use the load history data and the material fatigue properties to calculate the fatigue life for different stress levels, using the contemporary fatigue life approach. The stress level and fatigue life data are then related by a simple power function and the constants of this function are calculated. The stress level for a required life, or the fatigue life at certain stress level, can be obtained using the power function in a way similar to the S-N curve. To demonstrate the approach some test cases using the SAE keyhole specimen fatigue data, for different load histories, are presented.
Critical Speeds of Geared Rotors by Including Mesh Stiffness and Using a Continuous System Model
Authors: Sener O. Sedat , Ozguven H. Nevzat 
Published: April 2021

Abstract
Dynamic analysis of high speed gearing for the computation of critical speeds and dynamic factors is a must in a proper design, while some other dynamic characteristics of the system such as dynamic transmission error are to be determined for more critical designs. Numerous different models have been suggested for the dynamic analysis of geared systems. These models differ both in the effects included and in the basic assumptions made. A continuous system model is used in this analysis in order to determine the torsional natural frequencies of a gear shaft system composed of two gears, two shafts and two inertias representing the drive and the load. Gear mesh is modelled as a spring connected between two gears. The natural frequencies of the same system are also calculated by using a four degree of freedom classical discrete model in which shaft masses are ignored. The percentage differences in the natural frequencies calculated with the discrete and continuous system models are determined for several values of some nondimensional system parameters. The results are presented in graphical form in terms of the nondimensional parameters defined. Some conclusions which may be important for designers are drawn.
A Variational Approach for Modeling Flexibility Effects in Manipulator Arms
Authors: Meghdari A. 
Published: April 2021

Abstract
This paper presents a general technique to model flexible components (mainly links and joints flexibilities are considered) of manipulator arms based on the Castigliano’s theorem of least work. The robotic arms flexibility properties are derived and represented by the matrix of compliance coefficients. Such expressions can be used to determine the errors due to the robotic tip deformations under the application of a set of applied loads at the tip in Cartesian space. Once these deformations are computed, they may be used to correct for the positional errors arisen from the robotic structural deformations in the motion control algorithms.
Syntax and Semantics of an Image Communications Language for Design Management
Authors: Willett Shirley 
Published: April 2021

Abstract
The apparel industry is currently in crisis because of the lack of communication between different points in the design to manufacturing process. For communications tools to be useful to design management in the industry as a whole, they must be based on a language that supports standardization of representation, linkage of production information and product requirements to product representation, use of basic building blocks to avoid repetitive effort, and incorporation of syntactical information to aid in understanding of the represented product. It is this language, rather than the CAD/CAM systems which it makes possible, which is our unique contribution to the computerization of the industry.
Organizing the Tasks in Complex Design Projects
Authors: Eppinger Steven D. , Whitney Daniel E. , Smith Robert P. , Gebala David A. 
Published: April 2021

Abstract
This research is aimed at organizing complex design projects in order to perform faster product development. We use a variation of Steward’s design structure matrix [Steward 1981a] to represent both the sequence of and the technical relationships among the many design tasks to be performed. These relationships define the “technical structure” of a design project. We will develop analytical techniques to find alternative sequences and definitions of the design tasks, offering opportunities to speed development progress by improved coordination and information transfer. Our algorithms will consider the technical structure of a project in order to identify which tasks should be resequenced and which tasks should be redefined or split into smaller sub-tasks to avoid development bottlenecks. We will develop these techniques into a strategy for design management which can significantly reduce the overall project complexity by reorganizing the few critical tasks. We expect that this research will benefit not only new design tasks that have never been structured before but also long-standing, often repeated design tasks that may have drifted into poor organizational patterns over many years.
A Recursive Model for Managing the Design Process
Authors: Ward Allen C. 
Published: April 2021

Abstract
This paper introduces a model of the design process which challenges some commonly stated assumptions about design. For example, it holds that design should be normally be recursive rather than iterative; that we design and reason about sets of artifacts, not an artifact; and that we should normally not design to meet specifications. The model integrates and provides perspective on a variety of design methodologies, including Taguchi methods and QFD. It allows formal treatment of some key issues; for example, formal conditions can be identified for the concurrent development of products and processes.
Constraint Reasoning in Concurrent Design
Authors: Rinderle James R. , Krishnan V. 
Published: April 2021

Abstract
One paradigm of concurrent design is based on the simultaneous consideration of a broad range of life-cycle constraints including those arising from function, manufacturing and maintenance. This simultaneous treatment of life-cycle issues results in a multitude of constraints, which not only increase the complexity of finding a design solution, but also make it difficult to understand the trends and interactions underlying the design. It is our goal to enhance the designer’s ability to identify and discriminate those constraints that critically impact the design from those that are irrelevant. We propose an interval analysis based approach, which is augmented with monotonicity and dominance principles. The approach helps in identifying regions of the design space where constraints possess certain desirable properties. It also enables reasoning with constraints in these regions. The regional inferences can then be reassembled to obtain global results. These ideas have been applied in the concurrent design of a fan blade, to identify the dominant, active and redundant constraints, enabling the designer to more clearly perceive and base his decisions on the critical design consideration. Furthermore, the identification of dominant constraints permits the easy evaluation of the significance of newly asserted constraints and frequently facilitates the automatic formulation of noniterative constraint satisfaction methods which guarantee a globally optimal design.
Improving Mechanical Design Decisions With Alternate Formulations of Constraints
Authors: Watton John D. , Rinderle James R. 
Published: April 2021

Abstract
Mechanical design equations which relate performance and functionality to design variables are often highly coupled, nonlinear parametric equations. The structure of these interacting equations can be simplified by a reformulation based on alternative design variables. For many design configurations the reformulation results in highly beneficial improvement in equation monotonicity and complexity. The benefits include convenience and expediency in quantitative evaluations in addition to enhanced physical insight. They facilitate such important design activities as computing satisfactory solutions, active constraint recognition for optimizations, and the decomposition of design decisions. The reformulations can be thought of as alternative views of the design configuration that provide abstractions that can promote design synthesis. In this paper we discuss and illustrate the nature of these benefits with a number of simple design examples.
A Method to Identify Reformulations of Mechanical Parametric Constraints to Enhance Design
Authors: Watton John D. , Rinderle James R. 
Published: April 2021

Abstract
The complexity of mechanical design is reflected in the complexity of the design equations which relate functional requirements to design parameters. Reformulations of the design equations can significantly reduce this complexity. This is accomplished by a transformation to alternative design parameters, such as a critical ratio, a nondimensional parameter, or a simple difference; e.g. the ratio of surface area to volume for heat transfer loss, the Reynold’s number in fluid mechanics, or the velocity difference across a fluid coupling. We have developed a method by which the alternative parameters are chosen for physical significance and for the ability to create a more direct correspondence to functional behavior as determined by measures of serial and block decomposability of the constraints. Rules have been developed for the creation of physically significant new parameters from the algebraic combination of the original parameters. The rules are based on engineering principles and rely on knowledge about what a parameter physically represents rather than other qualities such as dimensions. A computer based system, called EUDOXUS, has been developed to automate this procedure. The system operates on a set of design constraints to produce sets of transformed constraints in terms of alternative design parameters. The method and its implementation have demonstrated successful results for many highly nonlinear and highly coupled parameterized designs from many mechanical engineering domains.
Methods for Process Selection in Design
Authors: Ishii K. , Lee C. H. , Miller R. A. 
Published: April 2021

Abstract
This paper describes our proposed methodology for process selection that applies to the early stages of product design. We focus on net-shape manufacturing processes and identify the major factors that affect the selection of an appropriate process. The sequence at which designers typically make decisions depends largely on the nature of the product and the development environment. Thus, a versatile methodology should consider all the factors simultaneously in assessing the suitability of the candidate processes. The paper describes three types of knowledge that represent the compatibility of various processes to a given set of specifications: a) Case-based knowledge, i.e., templates of good, bad, and poor combination of decisions, b) Ordinal relationships among candidate processes based on interval analysis of cost, and c) Life-cycle cost estimate. Each type of knowledge gives an evaluation of suitability (compatibility) of candidate processes. Our future challenge lies in combining these measures at various stages of product development. Our initial studies on relationships between process selection and influencing factors lead to a HyperCard stack which stores information in an object-oriented fashion. This stack contains information which is the basis for our future computer-aid for process selection.
Feature Based Approach for Casting Design
Authors: Padhy Sisir K. , Sharan R. , Dwivedi S. N. 
Published: April 2021

Abstract
The conceptual stage design is very crucial in a design phase because maximum flexibility lies in this stage. The product can be changed or redesigned to achieve the optimum blend of quality and cost. The factors that influence the design include: shape complexity factor of the product, material, and processing parameters. In the casting design, the shape-complexity factor plays a vital role in deciding the location of the gates and risers and hence in feeding system design. Feature based design is adopted for the evaluation of the shape complexity factor. The implementation of this design approach is also discussed.
The Use of Function and Form When Reading Mechanical Engineering Drawings by Experts and Non-Experts
Authors: Chovan John D. , Waldron Manjula B. 
Published: April 2021

Abstract
Function to form information used in reasoning about mechanical engineering drawings based on experience in design was investigated. The verbal utterances of expert mechanical designers, quasi-experts (graduate students) and novices while reading 13 mechanical engineering line drawings were recorded and analyzed for function to form relationships. A discriminant analysis of descriptions of these drawings showed similarities and differences between the design features used by each group when reasoning about the drawings. The results of this analysis and their implications for the development of intelligent CAD systems are discussed.