bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Direct Contact Problem in a Trochoidal-Type Machine
Authors: Shung John B. , Pennock Gordon R. 
Published: March 2021

Abstract
Reducing the contact forces in a trochoidal-type machine is important because the machine can not be adjusted for wear. The main difficulty in calculating the contact forces is to determine the forces that are transmitted through each contact point. Since there are many points of contact, at any instant, the problem is quasi-statically indeterminate and no satisfactory method of analysis is available in the current literature. The first part of this paper presents a simplified analytical model of a trochoidal-type machine when friction and deformation at the contact points are neglected. From this model, closed-form equations are derived for the normal contact forces. Then the second part of the paper presents a combined analytical and finite element model of the same machine. The analysis for the combined model includes the effects of friction and deformation at the contact points. The analysis for both models is for quasi-static conditions. The results from the two models are compared and important conclusions are drawn.
Determination of the Minimum Distance Between Moving Objects Including Velocity Information
Authors: Nahon Meyer 
Published: March 2021

Abstract
The rapid determination of the minimum distance between objects is of importance in collision avoidance for a robot maneuvering among obstacles. Currently, the fastest algorithms for the solution of this problem are based on the use of optimization techniques to minimize a distance function. Furthermore, to date this problem has been approached purely through the position kinematics of the two objects. However, although the minimum distance between two objects can be found quickly on state-of-the-art hardware, the modelling of realistic scenes entails the determination of the minimum distances between large numbers of pairs of objects, and the computation time to calculate the overall minimum distance between any two objects is significant, and introduces a delay which has serious repercussions on the real-time control of the robot. This paper presents a technique to modify the original optimization problem in order to include velocity information. In effect, the minimum distance calculation is performed at a future time step by projecting the effect of present velocity. This method has proven to give good results on a 6-dof robot maneuvering among obstacles, and has allowed a complete compensation of the lags incurred due to computational delays.
Application of the Monomial Method to Shape Optimization
Authors: Burns Scott A. 
Published: March 2021

Abstract
The monomial method is an alternative to Newton’s method for solving systems of nonlinear algebraic equations. It possesses several properties not shared by Newton’s method that enhance performance, yet does not require substantial computational effort beyond that required for Newton’s method. Previous work has demonstrated that the monomial method treats problems in structural design very effectively. This paper combines the monomial method with the method of generalized geometric programming to treat the problem of structural shape optimization of continuum structures modeled by finite elements.
Optimally Directed Truss Topology Generation Using Shape Annealing
Authors: Reddy Giridhar M. , Cagan Jonathan 
Published: March 2021

Abstract
This paper presents a technique for generation and optimization of truss structure topologies based on the shape annealing algorithm. Feasible truss topologies are generated through a shape grammar, in an optimally directed manner, using simulated annealing. The algorithm can incorporate a variety of constraints; stress and buckling constraints are employed in this paper.
Reconstruction of Sculptured Surfaces Using Coordinate Measuring Machines
Authors: Hsieh Yuan C. , Drake Samuel H. , Riesenfeld Richard F. 
Published: March 2021

Abstract
This paper presents a strategy for reverse engineering that uses a coordinate measuring machine to reconstruct three-dimensional sculptured surfaces. A rough initial model of the surface is generated manually. An iterative method is then used to refine the surface model. The reverse engineering is broken down into three phases: data acquisition, surface reconstruction and surface evaluation. For data acquisition, an exhaustive search algorithm is used to find a safe probe orientation in the vicinity of the target surface, and a coarse cell decomposition method is followed to manipulate the coordinate measuring machine in its work space. Surfaces are modeled by using the B-spline approximation technique, and position difference between the surface model and the measured data is used as a simple criterium to evaluate the quality of the reconstructed surface model.
On the Finite Screw System of the Third Order Associated With a Revolute-Revolute Chain
Authors: Huang Chintien 
Published: March 2021

Abstract
The finite displacements of the outermost body of a revolute-revolute chain are investigated. All the possible screws of the finite twists of the outermost body of an R-R chain are shown to form a screw system of the third order. The analytic expression of the screw system is given. The finite screw systems of special configurations of an R-R chain as well as the degenerate forms of the finite 3-system in infinitesimal kinematics and in displacing two points of a body are also discussed.
Layout of Extensional Surface Damping Treatment for Minimal Resonance Response
Authors: Wodtke Hans-Walter , Eschenauer Hans A. , Lamancusa John S. 
Published: March 2021

Abstract
The efficiency of using surface-mounted damping layers for noise-reduction of thin-walled (sheet metal) structures, largely depends on their distribution on the component. It is therefore attempted — by using FEM and Mathematical Programming (MP) procedures — to determine optimal layer distributions in such a way that the resonance amplitudes in a frequency interval become minimal. An approximation method based on damped single degree of freedom response functions is used for resonance tracking. Beams, circular plates and shallow spherical shells with unconstrained damping treatment are considered as application examples. It will be shown that an optimal layout of the layers can result in substantial reductions in sound radiation. These reductions result not only from an increase in damping and stiffness but may also be due to a modification of the vibration modeshapes.
A Multilevel Structural Approach to Optimal Earthquake-Resistant Structures
Authors: Thierauf Georg , Portillo-García Edwin 
Published: March 2021

Abstract
A new method for increasing of the ductility of seismic damaged structures is presented. The method combines efficient and well tested mathematical programming techniques with modern dynamic inelastic design concepts (explicit ductility balance). The results of this method are presented for reinforced concrete frames. The design variables are the longitudinal reinforcement and the cross-sectional dimensions at all member ends. A preliminary design is modified sequentially until the balance of ductility has reached a preselected distribution (optimization level II). Before the structural optimization starts, the actual ground motion is replaced by an equivalent one which contains only a few impulses and produces the same structural damage as the original earthquake (optimization level I). Based on this equivalent earthquake, the optimization problem can be solved and even direct methods for the time-integration of the non-linear dynamic equations can be included.
Application of Singular Value Decomposition for Static Equilibrium Analysis
Authors: Lew Jiann-Shiun 
Published: March 2021

Abstract
This paper presents an algorithm to determine the static equilibrium positions of general mechanical systems. The system generalized coordinates used in this paper are Cartesian coordinates. The Singular Value Decomposition (SVD) of the Jacobian matrix of constraints is used to separate the system coordinate space into the constraint space and the tangent space. This tangent space represents the system motion space and the coordinates corresponding to this space are chosen as independent coordinates. The coordinates corresponding to the constraint space are chosen as dependent coordinates. The sufficient and necessary condition for an equilibrium position is that the independent acceleration at this position is zero. This condition is used to develop an algorithm to find equilibrium positions. Examples will be used to demonstrate the algorithm developed in this paper.
Implementation of Decomposition Analysis in Optimal Design
Authors: Wagner Terrance C. , Papalambros Panos Y. 
Published: March 2021

Abstract
Decomposition analysis studies how one may explore systematically the decomposition of a given optimal design problem to a variety of decomposed formats that can be then treated by a specific decomposition method. This article presents the implementation of a decomposition analysis methodology introduced previously. The discussion focuses on the linking properties that can determine candidate partitions of the original problems. Suggestions are offered about how to define acceptable partitions. Examples illustrate the computational implementation of the methodology.
Approximation Concepts for the Decomposition-Based Optimization of Complex Mechanical Structures on Parallel Computers
Authors: Eschenauer Hans A. , Weinert Matthias 
Published: March 2021

Abstract
The present paper introduces a decomposition procedure for the optimization of complex mechanical structures, where the coupling structure of the generated subsystems is assumed to be non-hierarchical. Since the above decomposition procedure is suitable for a parallel solution, it is implemented on a parallel computer. The procedure is applied to the shape optimization of a shell of revolution.
Second Order Based Multidisciplinary Design Optimization Algorithm Development
Authors: Renaud J. E. 
Published: March 2021

Abstract
This paper reviews the effectiveness of a recently developed second order based multidisciplinary design optimization (MDO) algorithm in application to coupled engineering test problems. The second order based procedure significantly reduces the number of system analyses required for optimization as compared to first order based MDO procedures and single level optimization strategies. Based on these successes, this paper introduces a blueprint for an improved second order based MDO algorithm. The new algorithm is designed to provide additional design team compatibility and to exploit parallel computations during system optimization. The new algorithm introduces a modified non-hierarchic decomposition strategy (state space decomposition) that allows individual design teams to access the full design vector during concurrent subspace optimizations. Access to the the design vector in the new algorithm is now based on the local analyses capabilities of individual design teams. The coordination procedure of system approximation in the new algorithm will make use of second order global sensitivities. The new state space decomposition provides for the calculation of these sensitivities in parallel making use of local design data bases.
Closed-Form Primitives for Generating Volume Preserving Deformations
Authors: Chirikjian Gregory S. 
Published: March 2021

Abstract
In this paper, methods for generating closed-form expressions for locally volume preserving deformations of general volumes in three dimensional space are introduced. These methods potentially have applications to computer aided geometric design, the mechanics of materials, and realistic real-time simulation and animation of physical processes. In mechanics, volume preserving deformations are intimately related to the conservation of mass. The importance of this fact manifests itself in design, and in the realistic simulation of many physical systems. Whereas volume preservation is generally written as a constraint on equations of motion in continuum mechanics, this paper develops a set of physically meaningful basic deformations which are intrinsically volume preserving. By repeated application of these primitives, an infinite variety of deformations can be written in closed form.
Branch and Dead Position Problems of N-Bar Linkages
Authors: Ting Kwun-Lon 
Published: March 2021

Abstract
Based on the linkage rotatability theory, this article presents the first systematic and unified criteria to identify the existence of branch and dead positions of single closed-loop N-bar planar and spherical linkages or manipulators. It suggests that for any single-loop planar, spherical or even space linkages, the branch problem is irrelevant to the input conditions while the existence of dead positions depends on the type of kinematic chain and also the selection of the input links or joints. The proposed criteria and their simplicity are not affected by the type of applications nor by the use of coupler links as the input. They are also directly applicable to linkages with prism joints. Although the criteria are intended for computer use, the simplicity of these criteria allows one to develop geometric insight for graphic methods.
Parametric Deformations and Model Optimality in Concurrent Design
Authors: Rao J. R. Jagannatha , Chidambaram Bala 
Published: March 2021

Abstract
Concurrent modeling, as an emerging theme in engineering design research, also offers interesting new challenges in applied optimization. However, it is not always clear how best to construct mathematical models that represent such concurrent decision-making. In this paper, a class of engineering design problems, comprising analysis and synthesis tasks, is shown to be a two-player Stackelberg game with synthesis as the leader and analysis as the follower. Situations arising from a reversal of roles of the two tasks are studied and a Pareto model of a Design versus Analysis game is also investigated. Stackelberg games are then viewed in the larger context of concurrent design with design and manufacturing as two players. The potential benefits of such an approach are illustrated in the concurrent design of a stiffened plate structure.
Fractal Precision Models of Lathe-Type Turning Machines
Authors: Tumer Irem Y. , Srinivasan R. S. , Wood Kristin L. , Busch-Vishniac Ilene 
Published: March 2021

Abstract
The primary objective of this research is to develop surface models of machining processes to simulate machined surface profiles and analyze their structure. In this paper, fractal analysis is used to discover and characterize the variational pattern of turned surfaces. This analysis provides a means of explicitly stating the precision of a machining process. The results are used to further test the validity of the concept of fractal dimensions at tolerance scales and to establish a relation between surface models, experimental surfaces, and fractals. Based on these results, a more complete model of turning is available to designers for choosing process and design parameters and for comparing the precision between competing machining processes.
A Hybrid Shape Optimization Method Based on Implicit Differentiation and Node Removal Techniques
Authors: Shim P. Y. , Mannoochehri S. 
Published: March 2021

Abstract
This paper presents a hybrid shape optimal design methodology using an implicit differentiation approach for sensitivity analysis and a node removal technique for shape alteration. The approach presented attempts to overcome the weaknesses inherent in each individual technique. The basic idea is to combine the sensitivity analysis, which forms the analytical basis for the algorithm, and a node removal technique, which grossly modifies the shape without the need for a remeshing after each iteration. The sensitivity analysis is based on the finite element equilibrium equation and the implicit differentiation technique. It examines the effect positional changes of the boundary nodes have on the stress values. Using the sensitivity results, a sequential linear programming algorithm is utilized to determine optimum positions of the boundary nodes. These optimization results are provided as inputs to an algorithm that decides which boundary nodes should be removed. By removing boundary nodes, the boundary elements change to either a triangular or a non-existent type. This shape modification procedure starts from the boundary elements and moves toward the internal elements. Only two iterations of finite element analysis are required to modify one boundary layer. To maintain the structural integrity and the connectivity of the elements in the model, a connectivity check is performed after each iteration. Three design examples are given to illustrate the accuracy and the steps involved in the proposed optimal design methodology.
Information Management Support for Integrated Design Environments
Authors: Majumder Deeptendu , Rangan Ravi M. , Fulton Robert E. 
Published: March 2021

Abstract
This paper identifies key requirements for an advanced engineering design information management system. With the advent of information management technology and design automation, the definition of Computer Aided Design (CAD) systems has evolved beyond the realm of geometric data to include support for a very wide range of activities of an intelligent design agent — such as definition, manipulation and analyses of complex information models of a product. These information models represent not only conventional product data associated with typical CAD applications (FEM, NC, Geometric models, etc.), but also design information characterizing correlations between the requirements, function, behavior and form dimensions of the design. The new generation of CAD systems are expected to provide the designer with capabilities for defining, manipulating and reasoning with such models. These new functionalities are important to individual designers, as well as organizations as the need to manage information as a corporate asset is becoming a a critical facet of corporate strategies.
This paper explores these needs using design scenarios that trace the conceptual phases of design as well as the organization relevance to the design process. The first scenario deals with the innovative design of drilling applications for lunar environments, while the second scenario deals with the routine design of computer peripherals in a collaborative, multidisciplinary environment. These scenarios are used to elicit high level requirements, and subsequently the development of prototype systems. Preliminary results from the prototypes are presented herein.
Product Models in Simultaneous Engineering
Authors: Tegel Oliver 
Published: March 2021

Abstract
Simultaneous Engineering more and more becomes an important management instrument to shorten product development cycles. In addition, the tense cooperation between employees working in different departments or even different companies results in important synergy-effects.
To enable Simultaneous Engineering an infrastructure has to be build up far the handling of product data. Communication between the staff as well as communication between the CAX-Systems have to be managed efficiently, too. Product models adapted to the companies needs can push the efficiency of product development a step forward.
Designing the Future DDG 51 Class Computer Aided Design
Authors: Ouillette Joanne J. 
Published: March 2021

Abstract
The DDG 51 Class of AEGIS guided missile destroyers is the Navy’s premier surface combatant. Named for famed World War II hero. Admiral Arleigh Burke, these ships represent state-of-the-art technology. This 504 foot, 8,300 ton destroyer has been designed with improved seakeeping and survivability characteristics and carries the sophisticated AEGIS Weapon System. Derived from the Greek word meaning “shield”, AEGIS ships are the “shield of the fleet”. The Navy has commissioned the first two ships of the class. They have performed beyond expectation in rigorous at-sea trials designed to fully test combat capability.
The DDG 51 Class ships are replacing retiring fleet assets. In a decreasing Department of Defense (DoD) budget environment, however, acquisition costs must be reduced to continue to build capable warships. The Navy’s Destroyer Program Office is pursuing the implementation of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) technology to reduce costs without reducing ship’s capability.
Under Navy direction, the ship construction yards, Bath Iron Works and Ingalls Shipbuilding, are aggressively pursuing the transition to CAD-based design, construction, and life cycle support This effort also involves General Electric, the Combat System Engineering Agent. Building a three dimensional (3D) computer model of the ship prior to construction will facilitate the identification and resolution of interferences and interface problems that would otherwise go undetected until actual ship construction. This 3D database contains geometry and design data to support system design. Accurate construction drawings, fabrication sketches, and Numerical Control (NC) data can be extracted directly from the database to support construction at each shipyard. At completion of construction, a model representing the “as built” configuration will be provided as a lifetime support tool for each ship’s projected 40 year life.
The transition to CAD-based design and construction has applied fundamental concepts of the DoD’s Computer Aided Acquisition and Logistic Support (CALS) initiative. In addition to creating a 3D database representing ship design, the shipyards have developed a neutral file translator to exchange this data between Computervision and Calma CAD systems in operation at Bath Iron Works and Ingalls Shipbuilding respectively. This object oriented transfer capability ensures data is shared rather than duplicated. The CALS concepts of concurrent engineering and computer aided engineering analysis are being applied to design an upgrade to the ship that features the addition of a helicopter hanger. The CAD models are used as an electronic baseline from which to assess proposed modifications. Optimizing the design before the first piece of steel is cut will reduce construction costs and improve the quality of the ship.
A Logic-Based Mechanical System Constraint Model
Authors: Wu J. K. , Wang J. H. , Feng C. X. , Liu T. H. 
Published: March 2021

Abstract
This paper presents some initial developments in modeling design constraints of mechanical systems using predicate logic. This design constraint modeling method is to manage design changes in a concurrent engineering environment that has CAE and CAM applications. The design constraints are classified according to an object hierarchy of a mechanical system information model which has five levels object including: a mechanical system level, assembly level, and part level. The constraint relationships are defined and formally expressed using predicate logic. Feature fitting and against relationships between parts in the assembly level and relationships between features of a part in the part level have been illustrated in the paper.