bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visual Interaction in Acoustic-Structural Analysis of Automobiles
Authors: Gaddipati Vijoy , Vance Judy M. , DeVries Richard 
Published: March 2021

Abstract
This paper describes a graphical technique used for investigating the effects of structural design changes on the sound pressure levels generated in an automobile compartment. Low frequency noise in the passenger compartment (in approximately the 20–85 Hz frequency range) is of primary interest, and particularly that noise which is generated by the structural vibrations of the wall panels and various other smaller parts of the compartment. A designer faced with reducing the noise levels at various frequencies typically has several hundred design variables as candidates for change. This paper describes a computer interface that facilitates understanding of the effect various design changes have on the noise levels. This interface allows the designer to investigate the design space to determine which variables hold the most promise for achieving the objectives of noise reduction and allows the designer to set targets or constraints, to a desired confidence level, using the sensitivity information of these design variables. The design targets set in this manner are then input to an optimization algorithm which solves for the optimized sound pressure level.
A Robotic Software Developed Using Object-Oriented Design
Authors: Nesnas Issa A. D. , Stanisic Michael M. 
Published: March 2021

Abstract
Due to its inter-disciplinary nature, robotic design often involves the integration of various complex system constituents. As a result, a means to manage this complexity becomes highly desirable, if not essential. The use of object-oriented design and programming is one such means, whereby the system is decomposed into layers of object model hierarchies. The work presented here is part of a project that involved the design of a vision based robot system for planar path tracking. The object-oriented design and decomposition of the robot system software will be presented. The hierarchies of the system’s data abstractions will be analyzed and some of the advantages of using object-oriented techniques will be illustrated through simplified versions of the system’s abstractions. Examples on the concepts of encapsulation, inheritance, polymorphism, and single typing will also be discussed. The use of object-oriented programming not only provides extendable and reusable software, it also provides a better and more efficient means for software development.
MDL: A Methodology Description Language in a CAE Integration Environment
Authors: Wang Nanxin , Cheng Jie 
Published: March 2021

Abstract
A methodology description language (MDL) has been designed for the rapid integration of CAE programs in order to automate complex engineering methodologies. Based on this language, an integration environment has been developed, which includes a representation scheme for methodology process flow and data flow, and a control scheme for methodology process scheduling, monitoring, and potentially, diagnosis. The blackboard technique has been adopted in the implementation of the control scheme. This approach has now been tested in several projects to prototype engineering methodologies involving multiple CAE analysis programs. It is anticipated that full implementation and deployment of this approach inside Ford Motor Company will enable the rapid prototyping of complex engineering methodologies for exploration, as well as optimization, of product designs and vehicle control strategies. Widespread use of these results within the Ford product development process will be a key enabler to improving product quality through including more up-front CAE analysis of vehicle components and systems while still achieving Fast Cycle Time goals.
Rod Design: A Concept to Production Connecting Rod Design System
Authors: Chau Eric L. 
Published: March 2021

Abstract
A Concept to Production Parametric Design Environment for connecting rod design is described. The system utilizes state of the art knowledge based engineering, constraint based reasoning, computer aided engineering (CAE), design (CAD), and manufacturing (CAM) technology to achieve 80% lead time reduction on prototype parts with similar lead time reductions possible on production parts.
Optimization-Based Design of a Leg Mechanism via Combined Kinematic and Structural Analysis
Authors: Shieh W. B. , Azarm S. , Tsai L. W. , Tits A. L. 
Published: March 2021

Abstract
We study a recently proposed compound two degrees of freedom planar leg mechanism consisting of a four-bar linkage and a pantograph. In this mechanism, one degree of freedom is used for normal walking to provide an ovoid path which emulates that of humans while the other is used only when necessary to walk over obstacles. Potential advantages of such a compound mechanism are fast locomotion, minimal energy loss, simplicity in controller design, and slenderness of the leg. To exploit these to the fullest, a multiobjective optimization-based design problem formulation is proposed with the following four design objectives: (i) minimum leg height, (ii) minimum of the maximum joint forces, (iii) minimum leg mass, and (iv) minimum energy loss for a walking cycle. In addition, this problem formulation takes into account a combination of mechanism requirements and structural requirements. Several tradeoff solutions are obtained using the Consol-Optcad interactive optimization-based design package.
Statistical Verification of Conformance to Geometric Tolerance
Authors: Kurfess Thomas R. , Banks David L. 
Published: March 2021

Abstract
Modern coordinate measurement machines have provided industry with new tools for inspecting complex parts. This paper develops statistical procedures that complement these inspection methods, and it ties the conformance problem into the hypothesis testing formalism of conventional statistics. Also, the paper suggests strategies for efficient sampling of the part surface, and an implementation of the usual decision-theoretic formulation of the tradeoff between false acceptance and false rejection of part geometries. These ideas are illustrated through the analysis of real and simulated data for perfect and imperfect cylinders.
An Effective Method for Modelling Flexible Surfaces of Cloth Objects
Authors: Zhao Y. F. , Tan S. T. , Wong T. N. 
Published: March 2021

Abstract
In this paper a method for modelling the deformation of flexible objects such as cloth is presented in which the physical analysis can be imported into the geometric simulation. The geometric representations as well as the physical properties of flexible objects are considered. A so-called basic configuration and a constraint finite element method are given to improve previous methods for modelling flexible objects. The basic configuration is a primitive 3-D surface of a flexible object, and the constraint finite element method is a special finite element method with respect to the constraint conditions of the deformed flexible objects. The basic configuration of a deformed flexible surface can be directly obtained from its initial 2-D shape by using some control points and curves. Subsequently, according to the geometric constraint conditions of deformation, the basic configuration is adjusted to a satisfactory flexible surface by the constraint finite element method.
Generating and Flattening of Developable Surfaces
Authors: Gan M. C. , Tan S. T. , Chan K. W. 
Published: March 2021

Abstract
In this paper, methods for generating and flattening developable surfaces by means of two given directrix curves have been investigated. By finding the two end points of every generatrix, a developable surface may be formed. Such a developable surface may be flattened by rotating part of the surface about a generatrix. A new approach based on the principle of geodesic curve length preservation for flattening developable surfaces is also introduced. In this technique, an algorithm for evaluating the geodesic curvature of a point of a curve that lies on a surface is utilized.
Geometric Decompostion and Structural Shape Modification for Turbomachinery Blades
Authors: Hines Brian D. , Oliver James H. 
Published: March 2021

Abstract
An efficient and precise method is presented for the generation of turbomachinery blade models in nominal configuration, i.e., the “cold-shape” given the blade geometry at operating conditions, i.e., the “hot-shape.” The shape correction technique has two main components: a preprocessor that generates a plate finite element model of the hot-shape geometry, and postprocessor that performs the blade shape correction. The preprocessor decomposes the hot-shape blade surface model into a mean camber surface and an associated set of thickness functions. A plate finite element mesh is generated on the resulting mean camber surface. The finite element model is used as input for specialized analysis software for cold-shape correction which provides displacements due to unloading the blade. The postprocessor constructs the nominal cold-shape blade model in two steps. First, the nodal deflections are applied to the hot-shape finite element model to generate a cold-shape mean camber surface. Then the original hot-shape thickness functions are applied to the cold-shape mean camber surface to generate characteristic blade section curves which are lofted to define the cold-shape blade model. Several examples of turbomachinery blades in their hot-shape and resulting geometry are presented to demonstrate the capabilities of the technique.
Feature Recognition by Volume Decomposition Using Half-Space Partitioning
Authors: Shen Yan , Shah Jami J. 
Published: March 2021

Abstract
A volume decomposition method called minimum convex decomposition by half space partitioning has been developed to recognize machining features from the boundary representation of the solid model. First, the total volume to be removed by machining is obtained by subtracting the part from the stock. This volume is decomposed into minimum convex cells by half space partitioning at every concave edge. A method called maximum convex cell composition is developed to generate all alternative volume decompositions. The composing sub volumes are classified based on degree of freedom analysis. This paper focuses on the first part of our system, i.e., the volume decomposition. The other part of the work will be submitted for publication at a leter date.
An Efficient Strategy for the Robust Optimization of Large Scale Nonlinear Design Problems
Authors: Ramakrishnan Balaji , Rao S. S. 
Published: March 2021

Abstract
The application of the concept of robust design, based on Taguchi’s design philosophy, in formulating and solving large, computationally intensive, nonlinear optimization problems whose analysis is based on a linear system of equations is investigated. The design problem is formulated using a robust optimization procedure that utilizes the expected value of Taguchi’s loss function as the objective. An efficient solution scheme that uses approximate expressions for the gradients and employs a fast reanalysis technique for their evaluation is introduced. This approach is validated by solving a simple minimum cost 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 method is then used to obtain the optimal shape of an engine connecting rod, that minimizes its weight when subject to geometric constraints on the shape variables, and behavioral constraints such as stress and buckling loads. The results obtained by solving the conventional and robust formulations of this problem, and the considerable savings in time that result by virtue of using the fast reanalysis technique are presented. The methodology presented in this work is expected to be useful in reducing the computational effort in obtaining insensitive designs of large structures and machines.
Structural Optimization for Rubberlike Materials Using Analytical Sensitivity Analysis
Authors: Barthold F.-J. , Falk A. , Stein E. 
Published: March 2021

Abstract
We present a differential geometry based formulation of structural optimization which links continuum mechanics and computer aided design closely together to obtain very naturally fundamental sensitivity data for the optimization procedure. The subsequent discretization process end up with an elegant matrix representation of sensitivity analysis.
The derived sensitivity analysis and the overall optimization procedure was applied to solve structural optimization as well as parameter identification problems for nonlinear elastic materials modelling rubber.
An Octree-Based Heuristic Algorithm for 3-D Packing
Authors: Dai Zuo , Cha Jainzhong , Yuan Junliang 
Published: March 2021

Abstract
Based on the Object-Oriented Simulation System for 3-D Packing developed by Dai & Cha (1993a), this paper presents an effective heuristic algorithm using the Octree Data Structure for the three-dimensional packing problems of irregular components.
It also describes in detail the Tri-Ring Method which is designed for the topology identification of the octree’s construction. For those problems where the total volume of packed items is smaller than that of container, the results of the theoretical analysis and numerical experiments show that the heuristic is excellent both in packing quality and calculation cost. For those problems where the total volume of packed items is larger than that of container, a variant of this method is expected to be also quite effective.
The packing of arbitrarily shaped objects is achieved by packing their octrees generated from their EXTENTS or BOUNDING BOXES.
Design Optimization Considering Flexibility for Working Environment Based on Information of Pareto Optimum Solution Curvatures
Authors: Yoshimura Masataka , Nishikawa Takatoshi 
Published: March 2021

Abstract
This paper presents design decision making methods considering flexibility for change in the working environment. In order to make a clear evaluation of the changes in the optimum levels of the product cost and product performance due to changes in the working environment, three objective design optimization problems are constructed having the three objectives of minimization of the product cost, maximization of the product performance and maximization of flexibility for the working environment. The Pareto optimum solution set forming a curvature is obtained for the evaluation. Then, a method for determining the preferable design solution using information from the Pareto optimum solution curvature is presented. Finally, the proposed methods are applied to design examples for demonstrating effectiveness.
On the Optimal Design of Bodies With Material Symmetries
Authors: Landriani Giannantonio Sacchi , Taliercio Alberto 
Published: March 2021

Abstract
These notes are concerned with the optimal design of two dimensional, in-plane loaded structural elements and three dimensional bodies, made of aleotropic materials, with regard to both the elastic and the ultimate behaviour.
Sec. 2 is devoted to finding the local orientations of the material symmetry axes in 3D orthotropic solids, corresponding to extreme values of the global elastic stiffness. These orientations are shown to be such that collinearity of principal stress and principal strains is achieved throughout the body. In the particular case of transversely isotropic or cubic materials, optimal orientations are shown to depend both on a material parameter and the strain field. A certain orientation of the material symmetry axes may correspond either to a minimum or to a maximum in the elastic stiffness, depending on whether the material has ‘high’ or ‘low shear modulus’. These results are then specialized to plane orthotropic bodies, in which case the theoretical findings obtained by other authors are recovered. In the plane case, also simultaneous optimization of fiber orientation and density is dealt with.
Sec. 3 concerns optimal limit design of plastic 2D in-plane loaded orthotropic structures. Fiber orientation and density are assumed as design variables. Here again, necessary optimality conditions are analytically found and their mechanical interpretation is studied. Analogies with both the numerical results of other authors and the elastic case are observed and discussed as well.
Variable-Topology Shape Optimization With a Control on Perimeter
Authors: Haber Robert B. , Jog Chandrashekhar S. , Bendsøe Martin P. 
Published: March 2021

Abstract
This paper describes a new method for variable-topology shape optimization. The method addresses certain problems that arise in relaxed formulations (i.e., homogenization design methods). For example, a complete relaxation generates optimal designs containing material with perforated microstructures that may be difficult or expensive to manufacture. Formulations that penalize perforated material, either explicitly or through a partial relaxation, can generate manufacturable designs. However, the same illposedness that motivates relaxed formulations reappears as the penalty against perforated material is strengthened. The practical consequence is that numerical implementations of the penalized formulations fail to converge with grid refinement.
The new approach uses a control on the design perimeter to effectively exclude chattering designs (which have an infinite perimeter) from the feasible solution space. This achieves a well-posed shape design problem without the introduction of microstructure. Numerical examples demonstrate that manufacturable designs can be obtained in a single, automatic operation. Grid refinement improves geometric resolution without altering the design topology. The new method also provides a means to control the number and the length scale of holes in the optimal design.
A Unified Multidisciplinary Optimum Design Method Using Genetic Algorithms
Authors: Yamakawa Hiroshi 
Published: March 2021

Abstract
Multidisciplinary optimum designs have been of strong interest lately in many fields. A unified multidisciplinary optimum design method by utilizing the genetic algorithms is presented in this study. The design process is modeled there by a distributed hierarchical system to simulate ordinary design processes. Each level is optimized by genetic algorithms somewhat independently but some information is transmitted to the upper or the lower level. Engineering analysis can also be involved in a certain level. The proposed method is then applied to simple examples of preliminary designs of cars and numerical results show the effectiveness of the method.
Decision Decomposition for the Lifecycle of the Design Process
Authors: Fallin T. Wade , Thurston Deborah L. 
Published: March 2021

Abstract
Expanding design analysis to include lifecycle considerations makes design decision making more complex. This paper presents a methodology for structuring the lifecycle of the design decision making process itself in order to efficiently utilize designers’ time. The first step involves organizing performance objectives and decision variables into a hierarchical matrix structure defining the design space. Then, vertex partitioning is performed on a graph representation of the design space to delineate distinct stages where only a subset of decision variables are analyzed. An example of the parametric design of an artificial hip illustrates the methodology.
“Chaos” by Design in Mobile Robots
Authors: Shanmugasundram Arulkumar P. , Desa S. 
Published: March 2021

Abstract
A large class of tasks for mobile robots require the robot to cover an enclosed space that might contain several objects (obstacles). The usual approach to this problem is to design a sensor-intensive, computer-controlled robot that usually has a relatively simple kinematic form (type). The control of such a robot is difficult, expensive, and frequently unreliable. This paper demonstrates how the complexity in sensing and control can be circumvented by synthesizing a “chaotic” kinematic motion that, when appropriately embodied by a kinematic form, covers the space and easily deals with obstacles. The evolution of the “chaotic”, sensorless, mechanical mobile robot from concept, through analysis, numerical simulation and form embodiment, to realization is described. The testing of the prototype clearly demonstrates how, for the present task, complex “chaotic” motions do considerably simplify the control of the robot. A computer controlled prototype capable of mimicking the behavior of its mechanical counterpart is also described.
Numerical Algorithms for Mapping Boundaries of Manipulator Workspaces
Authors: Haug Edward J. , Luh Chi-Mei , Adkins Frederick A. , Wang Jia-Yi 
Published: March 2021

Abstract
Broadly applicable numerical algorithms for mapping boundaries of manipulator accessible output sets are developed and illustrated. Accessible output sets for planar and spatial manipulators are defined and analytical criteria determining their boundaries are stated, for both manipulators having the same number of input and output coordinates and redundantly controlled manipulators with a larger number of inputs than outputs. A method is presented for finding an initial point on the boundary of the accessible output set. From this point, a continuation method is used to map a family of one dimensional solution curves on the boundary. A method for finding tangents to solution curves at bifurcation points of continuation equations is presented and a computational implementation in the form of an experimental computer program is outlined. A planar redundantly controlled serial manipulator, a planar Stewart platform, and a spatial Stewart platform are analyzed, determining both the exterior boundary of the accessible output set and interior curves that represent local impediments to motion or controllability.
Dynamics of a Flexible-Link Planar Parallel Manipulator in Cartesian Space
Authors: Fattah Abbas , Misra Arun K. , Angeles Jorge 
Published: March 2021

Abstract
The subject of this paper is the modeling and simulation of a flexible-link planar parallel manipulator in Cartesian space. Given a desired end-effector motion, the inverse kinematics and inverse dynamics of a rigid-link model of the parallel manipulator is used to obtain actuated joint torques. The actual end-effector motion and vibration of the flexible links are obtained using simulation (direct dynamics) for the flexible-link manipulator. Finite elements are used to model the flexible links, while the Euler-Lagrange formulation is used to derive the equations of motion of the uncoupled links. The equations of motion of all the links are assembled to obtain the governing equations for the entire system. The methodology of the natural orthogonal complement, which has been previously applied to flexible-link systems with open-chain structures, is used here to eliminate the constraint forces. Finally, geometric nonlinearities in elastic deformations, which are very important in high-speed operations, are also considered.