bluuebunny/crossref_metadata_2025_split huggingface dataset:
Layout of Plate Structures for Improved Dynamic Response Using a Homogenization Method
Authors: Soto Ciro A. , Diaz Alejandro R. 
Published: March 2021

Abstract
A model to compute average properties for Mindlin plates of rapidly varying thickness was introduced in [SOT93]. The model was designed to be of use in computations of the optimum shape and layout of plates using the technique introduced by Bendsøe and Kikuchi [BEN88]. In this paper we discuss the utilization of the model to determine the optimum layout of plate structures that maximizes a function of the structure’s natural frequencies. A simply supported square plate is used to illustrate the problem of optimization in the presence of repeated natural frequencies. An automotive application is presented to illustrate the usefulness in design practice.
A Continuous Force Model for Elastic-Plastic Impact of Solids
Authors: Trabia Mohamed B. 
Published: March 2021

Abstract
A model for elastic-plastic impact analysis of solids is presented. This model is valid for the cases when plasticity accounts for the absorption of energy during impact. It is assumed that impact forces follow continuous Hertz contact force model. The model depends on a new mechanism for energy absorption in the impacted solids. The method yields the relative velocity of impact needed to initiate permanent deformation, coefficient of restitution, and impact time. As an example, impact between spheres is considered. Comparison between analytical and experimental results is included.
Adaptive Refinement for 3-D Finite Element Analysis
Authors: Muthukrishnan S. N. , Namblar R. V. , Lawrence K. L. 
Published: March 2021

Abstract
A simple strategy to adaptively refine three dimensional tetrahedral meshes has been implemented. A method of refinement for both plane faced and curve faced elements is presented in this paper. Examples are presented in which the rcmeshing is based on a refinement ratio determined from an a-posteriori error indicator obtained from the finite element solution of the problem. The resulting finite element meshes have a smooth gradient in element size. Example meshes are included to show the adaptive nature of the remesher when applied over several solution cycles.
Modeling and Analysis Method for a Compound Mechanism With a Cam and Linkages
Authors: Shiohata Koki , Ozawa Hiroshi , Utsmi Itsunori , Kobayashi Mitsuru , Fijisawa Fumio 
Published: March 2021

Abstract
In the dynamic analysis of a compound mechanism with a cam and linkages, cam contour equations are often used to produce solutions in polar coordinates. This requires calculating higher-order equations corresponding to the complicated non-cycloidal cam contours. In this paper, a new method is proposed to analyze the behavior of a cam with arc, straight and corner contours. This method is characterized by converting cam behavior into linkage behavior, that is, a cam is modeled by a linkage. This method can solve for the cam and linkage parts of a compound mechanism simultaneously using the conventional linkage analysis. The method is successfully applied to a numerical analysis of the dynamic behavior of the compound mechanism with a cam and linkages in an automatic teller machine. Further, the accuracy of calculation of the mechanism’s dynamic behavior is discussed for two analytical models, the series model and the parallel model.
A Sequential Approximation Method for Structural Optimization Using Logarithmic Barriers
Authors: Kumar Ashok V. , Gossard David C. 
Published: March 2021

Abstract
A sequential approximation technique for non-linear programming is presented here that is particularly suited for problems in engineering design and structural optimization, where the number of variables are very large and function and sensitivity evaluations are computationally expensive. A sequence of sub-problems are iteratively generated using a linear approximation for the objective function and setting move limits on the variables using a barrier method. These sub-problems are strictly convex. Computation per iteration is significantly reduced by not solving the sub-problems exactly. Instead at each iteration, a few Newton-steps are taken for the sub-problem. A criteria for moving the move limit, is described that reduces or eliminates stepsize reduction during line search. The method was found to perform well for unconstrained and linearly constrained optimization problems. It requires very few function evaluations, does not require the hessian of the objective function and evaluates its gradient only once per iteration.
Topology Optimization of 3D Trusses With Cost of Supports
Authors: Pedersen Pauli 
Published: March 2021

Abstract
The basic assumption for the present paper is the single load condition. In other aspects the stated problem is rather general and the important issue of local stability is taken into account. Even for this problem we can always find a statically determined topology that will minimize the cost of the structure.
The constraints of the optimization problem are allowable stresses, with the allowable compressive stresses being design-dependent. Supports are treated as design variables, and cost of a possible support can be given within the same generality as cost of truss members. The formulation is given in terms of bar forces and a modified Simplex technique is developed for the numerical solution.
Smooth Surface Fitting and Finite Element Mesh Generation for Irregularly Distributed Data Points
Authors: Chen Yih-Jen D. 
Published: March 2021

Abstract
This paper presents two computational methods for geometric modeling of curved surfaces represented by irregularly distributed data points. The study emphasizes irregularly distributed data points since this represents the most general case in geometric data interpretation. The first method is a direct mesh mapping procedure, which projects an relatively regular mesh to the complicated real surface. The second method is a surface fitting technique that reconstructs the mathematical surface model using piecewise bi-cubic parametric functions or B-spline functions. This data reconstruction method uses a normal-distance least-squares concept to generate the best fit. Recursive subdivision algorithm and quad tree data structure are applied to optimize the number of patches needed within the desired precision and thus minimize the computing time in the further processing of the surface model. A computer program based on the two computational methods in surface modeling has been developed and demonstrated by its engineering application. Its development provides an automated tool for design engineers and structure analysts to interpret and model complex surfaces derived from data points.
Reconstruction of B-rep Solid Models From Finite Element Meshes for Design Automation
Authors: Jablokow Andrei G. , Abraham Isaac 
Published: March 2021

Abstract
This paper presents the integration of Finite Element (FE) techniques with B-rep solid modeling. Algorithms for constructing B-rep solid models from a finite element meshes are presented. The finite element mesh data, which consists of node coordinates and connectivity information, is read in from any standard finite element analysis package (currently SDRC IDEAS and MSC/XL) and then processed to construct a polyhedral non-manifold B-rep solid model of the geometry. Since the finite element mesh of a solid object is essentially a non-manifold object, existing geometric modeling data structures based on two-manifold topologies cannot represent it directly. In this work the non-manifold radial-edge data structure is used for the internal representation of the finite element mesh. The mesh is then processed using non-manifold topology operators to eliminate internal nodes and elements to arrive at the solid model that is a polyhedral boundary representation. The results are useful for design automation through the integration of CAD with finite element analysis, shape optimization, as well as the manufacturing of geometry stored as a finite element mesh.
Motion Interpolation and Mechanism Synthesis
Authors: Ge Q. J. , Ravani B. 
Published: March 2021

Abstract
This paper studies planar motion approximation problems from a computational geometric perspective and develop a computational geometric structure that can be used for mechanical motion synthesis. This allows for development of computational algorithms and software systems to support the mechanical design activity. The approach uses an orientable kinematic mapping to transform the mechanical design problem into a curve design problem in the space of the mapping. The curve design problem for synthesis of an analytic motion is carried out by Hermite interpolation. In case of a mechanical linkage, however, the Hermite interpolation is combined with a first-order curve fitting procedure for synthesizing the motion.
Kinematic Synthesis of an RS-SRR-SS Adjustable Spatial Motion Generator for Three Alternate Tasks
Authors: Yao Jin , Xu Liju , Fan Shou-wen 
Published: March 2021

Abstract
A method is presented for kinematical synthesis of an RS-SRR-SS adjustable spatial motion generator for three alternate tasks. Three separate systems of synthesis equations to exactly generate the first and the last positions for each task are obtained for the R-S by co-plane and constant distance conditions, for the S-R-R by co-plane, constant distance conditions and inversion theory, and for S-S by constant distance condition. Based on these equations, mathematical model for approximately generating the intermediate positions for each task is formulated. This method is characterized by reduction of the unknowns and equations in both exact and approximate syntheses. As a result, computing work is to be decreased obviously.
Computational Efficiency of First and Second Order Sensitivity Analysis Methods for Dynamic Systems
Authors: Cao Qiushi , Krishnaswami Prakash 
Published: March 2021

Abstract
First and second order design sensitivity information have become very popular in engineering design, due to the recent development of appropriate methodology and computer technology. This paper presents an empirical study of the computing effort required for computing first and second order design sensitivity information for constrained dynamic mechanical systems and compares the relative efficiency of analytical and finite difference method. Four typical examples have been solved, with the computing time being recorded in each case. The time comparison results indicate that it is generally much more efficient to produce first order design sensitivity information by a direct analytical method than by finite differencing. For second order design sensitivity analysis, the results indicate that a purely analytical solution is usually more efficient than a pure finite difference solution. However, a hybrid scheme appears to be very competitive in terms of computational efficiency.
Optimal Design of Composite Lightweight Rollers
Authors: Bellendir K. , Eschenauer Hans A. 
Published: March 2021

Abstract
A well-aimed layout of fibre-reinforced lightweight rollers does not only require an efficient structural analysis procedure but also the application of structural optimization methods. Therefore, an analytical procedure is introduced for the calculation of the static behaviour of cylindrical shells subject to axisymmetric and/or nonaxisymmetric loads. In the scope of this procedure, arbitrary, unsymmetrical laminates as well as various boundary conditions will be considered. Basis is the shell theory by Flügge enhanced by anisotropic constitutive equations (material law) in the scope of the classical laminate theory. By means of mathematical optimization procedures we then determine optimal lightweight rollers, using different design and evaluation models. For that purpose, coated and uncoated roller constructions as well as hybrid types made of CFRP/GFRP will be applied. Concluding, we will discuss possible improvements and advantages of anisotropic lightweight rollers in contrast to isotropic ones made of steel or aluminium.
Vectorial Tolerancing for All Types of Surfaces
Authors: Martinsen Kristian 
Published: March 2021

Abstract
This article is a systematisation of Vectorial Tolerancing in order to show how it can be adapted to all kinds of surfaces on a workpiece. Vectorial Tolerancing provides a clear distinction between the different geometrical features size, form, location, and orientation for each surface. In Vectorial Tolerancing are location and orientation of a surface described with vectors in a Workpiece Co-ordinate System. The tolerance on the location and orientation vectors is described in the Tolerance Co-ordinate System. Only the fixed degrees of freedom are given tolerances on a surface.
An Object-Oriented Formalism for Geometric Reasoning in Engineering Design and Manufacture
Authors: Navaneethakrishnan Ravisrinivas , Wood Kristin L. , Crawford Richard H. 
Published: March 2021

Abstract
Geometry is a language for representing and communicating mechanical design information. To enhance the integration of design and manufacturing tasks, a representation of product geometry at appropriate levels of abstraction for geometric reasoning is necessary. In addition, a mechanism to perform reasoning with the representation is needed. This paper describes a computational formalism for representing and manipulating geometry at different abstraction levels. Geometry is abstracted in terms of form features. Spatial relationships between features, which are important components for geometric reasoning, are represented using a modification of a previously developed technique — the intermediate geometry language (IGL). To enable geometric reasoning, information abstracted using features and the IGL is transformed into a data model based on object-oriented modeling technology. An object algebra is defined to query the data model for information.
Application of Multidisciplinary Design Optimization to the Power Stage Design of a Power Converter
Authors: Kott Gregory , Gabriele Gary A. , Korngold Jacob 
Published: March 2021

Abstract
This paper describes the application of multidisciplinary design optimization to the power stage design of a power converter. The decomposition of the power stage design into an electrical and a loss subsystem is developed. The Sequential Global Approximation method is the non-hierarchic algorithm used to optimize the power stage design problem. Results of the non-hierarchic formulation compared to the non-decomposed formulation show a decrease of 63 percent in total system iterations required to converge to the optimal solution. Local and global move limits of 28 percent were found to provide the best performance for this problem.
The successful implementation and results of applying multidisciplinary design optimization to power stage design allows the extension of the research to incorporate other disciplines. Our goal is to include all disciplines to completely model the design of a power converter. The details of power stage design problem formulation are provided to be used as a test problem in multidisciplinary design optimization research.
Application of Stochastic Optimization Techniques at the Example of Ceramic Turbine Disks
Authors: Eschenauer Hans A. , Vietor Thomas 
Published: March 2021

Abstract
In comparison to metallic materials, ceramic materials are very brittle which has made a wide use of them difficult up to now. For this reason, stochastic failure criteria, which differ considerably from those of ductile materials, have to be formulated and calculated mathematically. Because of high specific elasticity and stiffness properties, the ceramics are suitable for the layout of rotating components with a high rotating velocity. In order to find the optimal layout of a component made of ceramic materials, a stochastic optimization problem has to be defined and solved.
A ceramic turbine disk has been chosen to demonstrate the shape optimization and the application of the stochastic optimization. By means of the functional-efficient boundaries and the associated optimal contours of the component conventional ductile materials are compared with ceramics for this application example. Herewith, the range of application of the materials examined can be determined.
Design Improvement by Simulation of Biological Growth
Authors: Mattheck Claus G. , Baumgartner Andreas , Kriechbaum Ralph G. , Walther Frank K. 
Published: March 2021

Abstract
Natural structures have been analyzed and investigated over many years for impulses and benefits that could possibly be applied to man-made technical structures. With today’s possibilities of computer-aided calculations, methods have been developed to improve the primitive research into nature by providing scientists with the tool of simulation for much preciser statements about the phenomena observed in the open.
K. Metzger, a German forester and author, reported on the existence of an even stress distribution in biological structures as early as 1893 (Metzger, 1893). For stems of spruce he observed that there is a definite relationship between the growth of stems and the mechanical loads which act on them. Metzger’s experience was adopted by a team of scientists at Kernforschungszentrum Karlsruhe GmbH. His observations have been providing the basis of extensive computerized simulations assisted by the finite-element method (FEM). Some of these calculations are discussed in this paper to prove and corroborate the theses given below.
Optimization of Helical Compression and Tension Springs
Authors: Metwalli Sayed M. , Radwan M. Alaa , Elmeligy Abdel Aziz M. 
Published: March 2021

Abstract
The primary objective of spring design is to obtain a spring which will do the required job and at the same time be the most economical for a given application. This means that the spring must fit into the available space and has a satisfactory life in service. The optimum springs would then have minimum weight, minimum length or minimum space. Various optimum values of wire diameter and spring index are obtained. These are evaluated in a closed form or utilizing iterative search techniques. The problem is formulated with and without the variation of the maximum shear stress with the wire diameter. The optimal parameters are also normalized and plotted.
Sculptured Surface Model Synthesis Based on Functional Design Constraints
Authors: Oliver James H. , Theruvakattil Philip C. 
Published: March 2021

Abstract
A technique is presented for the synthesis of sculptured surface models subject to several functional design constraints. A design environment is specified as a collection of polyhedral models which represent components in the vicinity of the design surface, or regions which the surface should avoid. The primary functional constraint is formulated as a proximity penalty function such that the design surface is induced to avoid a tolerance envelope around each component. In addition, a constraint based on surface area is formulated to counteract the expansion effect of the proximity constraint. Secondary design constraints are formulated to maintain consistent surface topology, and exploit part symmetry. Surface synthesis is thus formulated as an optimization problem and solved via simulated annealing. Several example applications are presented to demonstrate the capabilities of the technique.
A Non-Linear Machining Process Planner for Concurrent Mechanical Design
Authors: Ochiai Taro , Hoeltzel David A. 
Published: March 2021

Abstract
The performance of process planning systems is becoming increasingly more important within the context of concurrrent engineering. However, since planning strategies used in typical process planners cannot avoid combinatorial explosion without the appropriate use of domain heuristics, the planners cannot ensure acceptable performance for a more general class of machining problems. Using general non-linear planning techniques, we have developed a planner that attempts to cope with this problem. We establish a formulation for process planning using non-linear planning that enables graph-based conflict resolution. The planning mechanism is implemented using a production system in a computational experiment, and the possibility of generalization of this approach to other types of planning problems is discussed.
The STEP Integration Information Architecture
Authors: Yang Yuhwei 
Published: March 2021

Abstract
Traditionally, when the term “integration” is used to refer to the interoperability of disparate, heterogeneous computer system, it means the ability to exchange digital data between the systems. For the more sophisticated systems designers, “integration” may mean shared, distributed databases or a federated database system. Within the development of the Standard for the Exchange of Product model data (STEP - ISO 10303), “integration” refers to an information architecture composed of conceptual constructs that is independent of implementation considerations.
The Integration Information Architecture of STEP is presented and explained. Instead of a flat representation of abstract (i.e., conceptual) data structures, integration within STEP takes place at four different levels:
1) Intra-Resource integrated.
2) Structural integration of Application Protocols through Integrated Resources.
3) Semantic integration of Application Protocols through Application Interpreted Constructs (AICs)
4) Operational integration through Application Protocols.
Each level of integration and the relationships between the levels is explained.
Tight Integration and Synchronization of Distributed Graphical Applications
Authors: Mueller Wolfgang , Kleinjohann Bernd 
Published: March 2021

Abstract
Most engineering tasks are highly data intensive coping with the increasing complexity of systems. Gigabytes of heterogeneous engineering data have to be managed consistently by a huge array of tools. This necessitates sophisticated integration techniques based on a common database management system in order to decrease the amount of data that have to be exchanged between these tools.
In this paper we present a new approach to distributed design frameworks, integrating graphical as well as text processing tools. Tools may online share the same graphical and logical data synchronized by the event mechanism of an object management system. The synchronization concept is based on a tight integration into an object-oriented object management system and provides means to keep the graphical views of multiple agents consistent. We outline these concepts by the example of an integrated EXPRESS modeling workbench.