bluuebunny/crossref_metadata_2025_split huggingface dataset:
Full Beam Formulation for Coupled Elastic and Rigid Body Motion
Authors: Venkatakrishnan C. , Fallahi B. , Lai H. Y. 
Published: April 2021

Abstract
The need for higher operating speeds has led to the study of flexibility in mechanisms. In most of the previous works, rotary inertia, normal, tangential and coriolis terms are neglected. These assumptions are valid at lower speeds and for slender links. In this paper, a procedure to include all inertia terms in a local moving coordinate system is introduced. It is shown that the inertia terms lead to the introduction of three element matrices in the finite element formulation. The proposed approach is used to model the rotating beam problem. The results of a numerical solution is reported and validated.
A Collision Check Program for the IBM Sedab Two-Arm Robot
Authors: Eppinger Mike , Derby Stephen 
Published: April 2021

Abstract
This paper proposes an algorithm to check for collision between the two arms of the IBM SEDAB robot The collision check is based on static interference checks at discrete points along the selected trajectory. The points are equidistant and chosen such that the motion of all joints involved does not exceed given limits. The robot arms are modeled by a series of boxes, with each box representing a link. A collision check is performed by testing critical pairs of boxes for interference. The box - box interference tests involve excessive computation and are therefore time consuming. To reduce the number of necessary box interference tests, a quick test based on a rough model of the arms is used to determine the critical box pairs. This model consists of a series of spheres with one or two spheres circumscribing a box completely. Tools or parts fixed to the grippers can be included into the collision check.
Functionality in Surface Design
Authors: Lowe T. W. , Bloor M. I. G. , Wilson M. J. 
Published: April 2021

Abstract
The partial differential equation (PDE) method is used to generate surfaces which can be completely described using few parameters all of which have a global influence on the surface shape. We show how this method is suitable for the design of surfaces which optimize some property of the surface subject to certain given design restrictions. This is illustrated by considering two examples: the design of a yacht and the reduction of stress in a loaded blend.
Dynamic Collision Detection Using Space Partitioning
Authors: Ganter M. A. , Isarankura B. P. 
Published: April 2021

Abstract
A technique termed space partitioning is employed which dramatically reduces the computation time required to detect dynamic collision during computer simulation. The simulated environment is composed of two nonconvex polyhedra traversing two general six degree of freedom trajectories. This space partitioning technique reduces collision detection time by subdividing the space containing a given object into a set of linear partitions. Using these partitions, all testing can be confined to the local region of overlap between the two objects. Further, all entities contained in the partitions inside the region of overlap are ordered based on their respective minimums and maximums to further reduce testing. Experimental results indicate a worst-case collision detection time for two one thousand faced objects is approximately three seconds per trajectory step.
Sensitivity Analysis With the Shape Optimization Program
Authors: Atrek Erdal 
Published: April 2021

Abstract
SHAPE is an industry oriented commercial finite element based computer program for the shape optimization of continuum structures. It employs sensitivity analysis extensively during optimization. A new option allows the user to create, access, and plot sensitivity information for any prescribed design that can be processed by SHAPE. This feature of the program is described herein, and is illustrated by means of numerical examples.
Dimensional Tolerance Allocation of Stochastic Dynamic Mechanical Systems Through Performance and Sensitivity Analysis
Authors: Lee S. J. , Gilmore B. J. , Ogot M. M. 
Published: April 2021

Abstract
Uncertainties due to random dimensional tolerances within stochastic dynamic mechanical systems lead to mechanical errors and thus, performance degradation. Since design standards do not exist for these systems, analysis and design tools are needed to properly allocate tolerances. This paper presents probabilistic models and methods to allocate tolerances on the link lengths and radial clearances such that the system meets a probabilistic and time dependent performance criterion. The method includes a general procedure for sensitivity analysis, using the effective link length model and nominal equations of motion. Since the sensitivity analysis requires only the nominal equations of motion and statistical information as input, it is straight forward to implement. An optimal design problem is formulated to allocate random tolerances. Examples are presented to illustrate the approach and its generality. This paper provides a solution to the tolerance allocation problem for stochastic dynamically driven mechanical systems.
Engineering Design: A Perspective on U.K. and Swiss Developments
Authors: Eder W. Ernst 
Published: April 2021

Abstract
Historic developments, and the current state of the art are surveyed in thought, theory, methods and methodology, and education for and about engineering design. This survey covers two particular and disparate regions, the United Kingdom, and Switzerland, the latter including the activities of an international group centered in Zürich known as WDK — Workshop Design-Konstruktion.
Design Science: Meta-Science to Engineering Design
Authors: Eder W. Ernst 
Published: April 2021

Abstract
Following on from a paper presented at a previous Design Automation Conference (Eder 1986), this paper outlines some of the more recent insights concerning engineering design that have been developed by a small international group. Some of the models of designing and technical systems have been improved. A morphology of knowledge about designing and technical systems has been proposed, and extended to a morphology of knowledge itself. Some consequences are drawn from these developments, and summarized in this paper.
Accelerated Testing for Reliability
Authors: Smith C. O. 
Published: April 2021

Abstract
The designer of a product must determine if the design objective of reliability and/or product life has been met. This is normally accomplished by testing prototypes or early production units. Because of the time required to test, it is not very realistic to test under normal operating conditions. Accelerated testing is highly desirable. This paper discusses (1) some testing methods for determining the most significant variables affecting performance and (2) some techniques for reducing the time required to estimate reliability or product life.
Comparison of Weibull Strength Parameters From Flexure and Spin Tests of Brittle Materials
Authors: Holland Frederic A. , Zaretsky Erwin V. 
Published: April 2021

Abstract
Fracture data from five series of four-point bend tests of beams and spin tests of flat annular disks were reanalyzed. Silicon nitride and graphite were the test materials. The experimental fracture strengths of the disks were compared with the predicted strengths based on both volume flaw and surface flaw analyses of four-point bend data. Volume flaw analysis resulted in a better correlation between disks and beams in three of the five test series than did surface flaw analysis. The Weibull slopes (moduli) and characteristic gage strengths for the disks and beams were also compared. Differences in the experimental Weibull slopes were not statistically significant. It was shown that results from the beam tests can predict the fracture strength of rotating disks.
A Criticism of an Undergraduate Design Curriculum
Authors: West Harry 
Published: April 2021

Abstract
The mechanical engineering design curriculum of one university (MIT) is outlined. The sophomore level Introduction to Design course and the senior level Design Projects course are described in more detail, and compared and criticized.
The challenge of design education is ascribed to two sources: (a) the reach of design development that is expected of the students, and (b) the difficulty of providing adequate feedback to the students. It is proposed that (i) the limitations on the science based undergraduate curriculum for providing a professional education in design be formally recognized, and that there be a clearer understanding of what a graduating engineer is expected to be capable of, and what is to be provided by graduate school and/or company based on-the-job training programs; (ii) that established principles of design be taught at appropriate stages in the undergraduate curriculum to the extent that they match the students’ design development and experience; and (iii) that undergraduate design courses incorporate projects in which students’ designs are manifested in hardware to provide an effective complement to the feedback provided by the faculty teaching the course.
Multivariate Yield Maximization Using CAD/CAE Models: Efficient Approximations Based on Mean and Variance
Authors: Barton Russell R. , Tsui Kwok-Leung 
Published: April 2021

Abstract
A product contributes to yield if all of its performance functions fall within their upper and/or lower limits. For example, a piston connecting rod may be required to provide rigidity along several axes. The actual connecting rod deflection will vary, depending on variations in the materials and forging conditions, but the deflection must remain less than an upper limit. Designing for maximum yield for multivariate performance limits is a difficult task. Direct optimization may require excessive computing resources. We discuss two efficient methods for yield improvement: ‘performance centering’ and a method based on Taguchi’s ‘parameter design’ philosophy. Both are shown to be motivated by the Chebychev inequality. It is important to remember that these are approximate methods. An example shows that they may produce sub-optimal yield, even when the random components of the performance functions are independent and identically distributed.
A Methodology for Conversions of Feature-Based Representations
Authors: Rosen David W. , Dixon John R. , Dong Xin 
Published: April 2021

Abstract
Computer integrated manufacturing practices require the sharing of product information between functions, which is the larger context for the work presented in this paper. We are addressing the problem of converting from one feature-based representation to another, where the second representation is for a different application than the first. In particular, we are focusing on converting a design-with representation of a component into representations suitable for manufacturability evaluations. We offer a methodology for describing conversions as a three-step process: filtering information, such as features and geometry, out of the primary representation, selecting those entities that satisfy conditions appropriate to the secondary viewpoint, and aggregating entities into secondary viewpoint features. This methodology is applied to the conversion of a component from the design viewpoint to the injection molding viewpoint for the purposes of tooling cost evaluation. Results from the injection molding conversion, and several others under development, show that our methodology supports conversions at early design stages and suggests broad applicability.
Conceptual Design of Mechanical Systems
Authors: Welch Richard V. , Dixon John R. 
Published: April 2021

Abstract
This paper presents a method for generating solutions to a class of conceptual design problems. We define conceptual design as the transformation of functional requirements to abstract physical systems in two stages: 1) phenomenological design — transforming a functional requirement to a behavior description by using physical principles; and 2) embodiment design — transforming the behavior specification to a physical embodiment that exhibit the required behavior. In order to reason about the behavior of in-progress designs, a new representation called behavior graphs has been defined. Behavior graphs are similar to bond graphs but have been developed as a design tool. (Bond graphs were developed as an analysis tool.) In order to guide the design process, the iterative redesign model of design is used at both the phenomenological and embodiment levels. The behavior graph representation and iterative redesign model constitute the conceptual design method presented here. A experimental computer program implementing this method is discussed and illustrative examples presented.
A Knowledge Base Data Representation for Collaborative Mechanical Design
Authors: Nagy Richard L. , Ullman David G. , Dietterich Thomas G. 
Published: April 2021

Abstract
Collaborative design projects place additional burdens on current design documentation practices. The literature on group design has repeatedly documented the existence of problems in design decision making due to the unavailability of design information. This paper describes a data representation developed for collaborative mechanical design information. The data representation is used to record the history of the design as a sequence of design decisions. The resulting knowledge base records the final specifications, the alternatives which were considered during the design process, and the designers’ rationale for choosing the final design parameters. It is currently used in a computerized knowledge base system under development by the Design Process Research Group (DPRG), at the authors’ institution (OSU).
Solving Parametric Design Problems Requiring Configuration Choices
Authors: Ramaswamy Rajan , Ulrich Karl T. , Kishi Norimasa , Tomikashi Minoru 
Published: April 2021

Abstract
Many design tasks involve selection from a set of configurations followed by parametric optimization of the chosen configuration. The models used for these tasks tend to be large, non-linear and involve both discrete and continuous variables. It is rarely possible to use any single formal algorithm to solve these problems and as a result there are few tools to help designers solve such problems. We believe computer environments that allow flexible access to a varied set of tools will help designers rapidly generate high quality solutions. We demonstrate our arguments on a design problem taken from a commercial auto manufacturer, propose a framework for dealing with the general class of problems and describe an implementation of a novel design system that integrates math programming, knowledge-based and graph theoretic tools.
Methods for Analyzing Design Procedures
Authors: Gebala David A. , Eppinger Steven D. 
Published: April 2021

Abstract
This paper surveys several common models which can be used to represent and study design procedures. A matrix representation of design is discussed in detail and both new and existing analysis tools are presented. Enhanced models are proposed to incorporate more information into the matrix representation and to allow more sophisticated analysis to be performed. The paper describes a testbed for the development and testing of algorithmic analysis tools and concludes with suggestions for further research into improving the design process.
A Robust Optimization Approach Using Taguchi’s Loss Function for Solving Nonlinear Optimization Problems
Authors: Ramakrishnan Balaji , Rao S. S. 
Published: April 2021

Abstract
The application of the concept of robust design, based on Taguchi’s loss function, in formulating and solving nonlinear optimization problems is investigated. The effectiveness of the approach is illustrated with two examples. The first example is a machining parameter optimization problem wherein the production cost, tool life and production rate are optimized with limitations on machining characteristics such as cutting power, cutting tool temperature and surface finish. The second example is a welded beam design problem where the dimensions of the weldment and the beam are found without exceeding the limitations stated on the shear stress in the weld, normal stress in the beam, buckling load on the beam and tip deflection of the beam. The results are highlighted by comparing the solutions of the robust formulation with those obtained from the conventional formulation. The methodology presented in this work is expected to be useful in the design of products and processes which are least sensitive to the noises and which reflect in higher quality.
Geometric Reasoning Based on Graph Grammar Parsing
Authors: Fu Zhuo , de Pennington Alan 
Published: April 2021

Abstract
It has been recognized that future intelligent design support environments need to be able to reason about the geometry of products and to evaluate product functionality and performance against given constraints. A first step towards this goal is to provide a more robust information model which directly relates to design functionality or manufacturing characteristics, on which reasoning can be carried out. This has motivated research on feature-based modelling and reasoning. In this paper, an approach is presented to geometric reasoning based on graph grammar parsing. Our work combines methodologies from both design by features and feature recognition. A graph grammar is used to represent and manipulate features and geometric constraints. Geometric constraints are used within symbolic definitions of features and also to define relative position and orientation of features. The graph grammar parsing is incorporated with knowledge-based techniques to derive feature information and propagate constraints. This approach can be used to the transformation of feature information and to deal with feature interaction.
Analysis of 3-D Elastic Contact Stresses for the Cylinder Head of an Internal Combustion Engine: An Improved Mixed Finite Element Method
Authors: Li Ming-Zhang , Jun Yu , Huang Yu-Ying , Zha Jian-Zhong 
Published: April 2021

Abstract
In this paper, an improved mixed finite element method (FEM) for analysing elastic contact stresses is presented. Since the corresponding softness matrix symmetrized, the main advantage is that not only is the computation efficiency is improved, but also the data storage is reduced in comparison with the usual mixed FEM. A set of computation formulas of FEM for 3-D elastic contact problems with friction is established and realized on digit computers. A numerical example compared with the results obtained by ADINA shows that the present approach is very efficient and reliable.
Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller
Authors: Ramamurti V. , Subramani D. A. , Sridhara K. 
Published: April 2021

Abstract
Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.
An Approach to Dynamic Distance Calculations for Obstacle Avoidance Problems
Authors: Liu C. Y. , Chen W. R. , Mayne R. W. 
Published: April 2021

Abstract
This paper presents a distance calculation method which can be used in machine motion planning optimizations where interference is a concern. Dynamic distance calculations are discussed which use the quadratic programming method combined with an approximate swept volume approach. Distance-to-contact calculations can be obtained for both interference and non-interference situations. The swept volume of a moving polygon is constructed through a series of overlapped swept volume segments. Each of the swept volume segments is efficiently developed by checking the inner products of polygon outward boundary normals with velocity vectors for polygon vertices. Two dimensional examples of distance-to-contact computations and robot path planning problems are presented for a sample three link robot with three rotational joints.
Design Considerations for Vibration Assisted Compliant Assembly
Authors: Liu Y. , Leu Ming C. 
Published: April 2021

Abstract
This paper presents design considerations for vibration assisted compliant assembly involving peg-in-hole insertion. We propose a feasible parts mating assembly model, based on the positional uncertainty and tolerance of an assembly task. For an infeasible task, whose tolerance set does not contain the uncertainty set, it is proposed to introduce a relative motion between the two mating parts, so as to enlarge the task tolerance relative to its uncertainty. A specific type of such motion, viz vibration in two orthogonal directions, is studied in detail. The amplitudes and frequencies of vibrations are determined for given tolerance, uncertainty, and other assembly parameters. A numerical procedure is devised to select the ratio of the two orthogonal vibration frequencies, for minimum search time of parts engagement. Criteria on suitable compliances for assembly are proposed, with consideration of insertion failure.
Noise Reduction of Engine Component Covers Using the Finite Element Method
Authors: Sivakumar Jayaraman , Sung Shung H. , Nefske Donald J. 
Published: April 2021

Abstract
Radiated noise from an engine component cover is predicted by using a structural finite element model of the cover to predict its forced vibration response, and then by using the Rayleigh integral method to predict its radiated noise. Applications to evaluate the radiated noise from an engine rocker cover and an engine front cover are presented. Measurements of the radiated noise from actual covers installed on a running engine show the predicted noise reduction due to structural modifications is achieved.
A Singular Perturbation Analysis of Eigenvalue Veering and Mode Localization in Perturbed Linear Chain and Cyclic Systems
Authors: Happawana G. S. , Bajaj A. K. , Nwokah O. D. I. 
Published: April 2021

Abstract
An investigation into the eigenvalue loci veering and mode localization phenomenon is presented for mistuned structural systems. Examples from both, the weakly coupled uniaxial component systems and the cyclic symmetric systems, are considered. The analysis is based on singular perturbation techniques. It is shown that uniform asymptotic expansions for the eigenvalues and eigenvectors can be constructed in terms of the mistuning parameters, and these solutions are in excellent agreement with the exact solutions. The asymptotic expansions are then used to clearly show how the singular behavior in the eigenfunctions or modeshapes leads to mode localization.
Analysis of Dynamic Systems With Periodically Varying Parameters via Chebyshev Polynomials
Authors: Sinha S. C. , Wu Der-Ho , Juneja Vikas , Joseph Paul 
Published: April 2021

Abstract
In this paper a general method for the analysis of multidimensional second-order dynamic systems with periodically varying parameters is presented. The state vector and the periodic matrices appearing in the equations are expanded in Chebyshev polynomials over the principal period and the original differential problem is reduced to a set of linear algebraic equations. The technique is suitable for constructing either numerical or approximate analytical solutions. As an illustrative example, approximate analytical expressions for the Floquet characteristic exponents of Mathieu’s equation are obtained. Stability charts are drawn to compare the results the proposed method with those obtained by Runge-Kutta and perturbation methods. Numerical solutions for the flap-lag motion of a three blade helicopter rotor are constructed in the next example. The numerical accuracy and efficiency of the proposed technique is compared with standard numerical codes based on Runge-Kutta, Adams-Moulton and Gear algorithms. The results obtained in the both examples indicate that the suggested approach extremely accurate and is by far the most efficient one.