bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating Technology Insertion Risk Using Fuzzy Logic
Authors: Yates Don , Butler Alley
Published: November 2020

Technology insertion into an existing system or subsystem requires careful planning and evaluation. Because the technology is new, there is often limited information upon which to base decisions. Further, decisions about technology insertion are typically made in the very early stages of a project when detailed information is sparse. Under these circumstances, the available information is typically linguistic, and fuzzy methods can be used to significant advantage in this environment.

The implementation discussed in this paper employs an Excel spread sheet for user interface, and it employs COTS (Commercial Off the Shelf Technology) software for an inference engine. Heuristic based models are developed to evaluate risk in technology insertion. Risk elements include: budget risk, schedule risk, and performance risk. Results with an example problem are described to illustrate the fuzzy logic method, and conclusions are drawn regarding the advantages of this technique.
Fuzzy Logic Application in Data Acquisition
Authors: Sule Dileep R. , Watkins Tory K. , Restifo David
Published: November 2020

The aim of this paper is to introduce an expansion of the practice of using surveys when making subjective judgments or decisions. This method is particularly useful in situations in which precise data is limited or nonexistent. It can be especially valuable when working with new designs by reducing the error associated with estimates in the beginning of the product’s life cycle in which costs are greatest. Our approach modifies the traditional survey style by including fuzzy logic and expert judgment. Using fuzzy logic, we solicit the information in a way that gives the evaluator a continuous choice for the cost estimate and a method to indicate the level of confidence in a linguistic manner. By doing this, a range of the likely values for the real value can be defined, and a subjective judgment can be turned into objective information that can be more useful than the traditional approach.
A Study on Distributed CIMS Analysis and Design
Authors: Li Renwang , Xiao Renbin , Qi Guoning
Published: November 2020

The concurrent collaborative working environment between teams is helpful to facilitate people to communicate freely. However, it is still impossible for people to describe CIMS accurately due to the lacking of efficient communication tools offered by the research on the CIMS analysis and design up to now. The main characteristics and bottlenecks of distributed CIMS analysis and design have been elucidated comprehensively in this paper. On the basis of the above work, a concrete distributed CIMS analysis and design software system, which was developed by the authors and others, was introduced and illustrated through a practical enterprise.
Practical Considerations and Lessons Learned in Setting up a Virtual Reality System for Industrial Virtual Prototyping
Authors: De Kroon Joseph P. , Bras Bert
Published: November 2020

In this paper we present issues to be considered by those who are interested in setting up a practical Virtual Reality (VR) system for virtual prototyping. The considerations discussed in this paper are based on lessons learned in a virtual prototyping implementation project undertaken with an industrial partner. We propose a classification of virtual prototyping applications into two main categories, which provide the basis for a simple tool that, although subjective, can serve as a decision-making aid in selecting a VR system for particular tasks, or in determining which VR tasks to attempt with a given system.
Physically Based Modeling in Virtual Assembly
Authors: Wang Yong , Jayaram Uma , Jayaram Sankar , Lyons Kevin
Published: November 2020

Virtual assembly is a promising application of virtual reality in design and manufacturing and has drawn much attention from industry and research institutes. Physically based modeling has been an important research topic in computer graphics and virtual reality. In this paper, physically based modeling issues in virtual assembly are investigated. The specific requirements and characteristics of physically based modeling in virtual assembly versus those in traditional computer graphics are analyzed and studied. The mass properties of the assembly models are extracted from the Computer Aided Design (CAD) system while the design models are transferred from the CAD system to the virtual assembly environment. This added information allows the assembly models to be categorized using human strength survey data. The interaction of parts, environment objects, and the human are analyzed. In the fully immersed virtual environment, it is discovered that certain presentations of gravitational acceleration needs to be scaled down to achieve maximum realistic feeling. Finally the benefits and limitations of physically based modeling in virtual environments are discussed.
Definition Clarification and Review on Virtual Prototyping
Authors: Wang G. Gary
Published: November 2020

Virtual Prototyping (VP) technique has been interpreted in many different ways, which causes confusion and misunderstanding among researchers and practitioners. Based on a review of the current related application and research, this paper gives a clarified definition of VP as well as its essential components and functions. VP is then compared with and distinguished from virtual reality (VR), virtual environment (VE), and virtual manufacturing (VM) techniques. Given the clarified definition, benefits and limitations of VP are analyzed and future VP related research topics are suggested.
A Haptics-Based Virtual Environment for Engineering Design and Manufacturing Applications
Authors: Sharma Cartik , Kesavadas T.
Published: November 2020

Haptic technology is revolutionizing the way engineers interact with computers. Haptics allow people to directly interact with digital objects and data as they do in the real world using their sense of touch. Hitherto, designers and artists have used haptics to intuitively sculpt models using digital clay and doctors have trained on haptics based virtual surgical simulators. Most applications however merely seek to make up for the lack of sense of touch and its effects. The following paper investigates the application of the haptics loop using decision support activities in core engineering areas like design optimization and shop floor lay out. An architecture combining large-scale visualization environment with haptics is proposed. The interaction of multiple loops running an application and the procedural advantages and difficulties faced are addressed. Finally, the Virtual Factory environment (VFACT) is used as a test-bed to validate the efficacy of haptics for facility design and layout. A prototype using haptics for intuitive exploration of the design space for single row machine layout problem is implemented.
Automatic Unstructured Mesh Generation Around Two-Dimensional Domains Described by B-Spline Curves
Authors: Flórez Guzmán Horacio , Manzanilla Morillo Raúl
Published: November 2020

A computer code for the generation of unstructured two-dimensional triangular meshes around arbitrary complex geometries has been developed. The code is based on Delaunay triangulation with an automatic point insertion scheme and a smoothing technique. The geometrical definition of the domain to be meshed is prescribed by means of B-spline curves obtained from two approaches of interest in Computer-Aided Geometric Design named inverse design and interpolation problems. The presented scheme is based on an interpolation procedure along a B-spline curve proposed by the author in a recent paper. This technique prevents that the resulting grid may overlap convex portions of the boundaries. The main goal is to study the possibility of extend the methodology of unstructured grid generation beginning with boundaries described by polylines to other in which they are prescribed by piecewise polynomials curves capable to drive more realistic problems. Several figures and examples from Computational Fluid Dynamics have been included to show the various steps of the algorithm. The results show that the code is able to solve the problem of automatic grid generation in a robust manner opening new perspectives for the development of a black-box grid generator.
On the Identification of Hysteresis in Inelastic Systems
Authors: Ma Fai
Published: November 2020

The generalized model of differential hysteresis contains thirteen control parameters with which it can curve-fit practically any hysteretic trace. Three identification algorithms are developed to estimate the control parameters of hysteresis for different classes of inelastic structures. These algorithms are based upon the simplex, extended Kalman filter, and generalized reduced gradient methods. Novel techniques such as global search and internal constraints are incorporated to facilitate convergence and stability. Effectiveness of the devised algorithms is demonstrated through simulations of two inelastic systems with both pinching and degradation characteristics in their hysteretic traces. Due to very modest computing requirements, these identification algorithms may become acceptable as a design tool for mapping the hysteretic traces of inelastic structures.
MATLAB in Engineering Education
Authors: Alimi M. H. , Mahinfalah M. , Nazari G. H.
Published: November 2020

One of the most important aspects of engineering education is problem solving. This paper intends to show how MATLAB can be utilized to solve various problems in science and engineering. A simple vibration problem is solved using MATLAB’s ODE solver to illustrate the excellent capability of MATLAB in numerical integration of matrix differential equations.
Interaction Modeling in Systems Design
Authors: Sinha Rajarishi , Paredis Christiaan J. J. , Khosla Pradeep K.
Published: November 2020

We present a simulation and design framework for simultaneously designing and modeling electromechanical systems. By instantiating component objects in our software and connecting them to each other via ports, the designer configures complex systems.

Interactions are the physical phenomena that occur at the interfaces between connected components. Most of the research in configuration design has focused on modeling components, with very little attention paid to the dynamics of the interaction phenomena. To obtain an accurate virtual prototype, the interaction dynamics must also be captured in behavioral models.

All interactions between components are mediated by ports. We introduce port and interaction model taxonomies, and provide a set-theoretic formalism that defines the algebra of port and interaction models. In addition, the formalism supports automatic instantiation of interaction models given the types of the connected ports, as well as the ability to replace one interaction model for another depending on the requirements of the desired simulation experiment. We illustrate our framework with an example.
Vehicle Analysis Using an Agent-Based Analysis Tools Framework
Authors: Gee Ken
Published: November 2020

Methods to combine a number of analysis tools into an agent-based integrated design system (IDS) for aerospace vehicles were developed. Computer-aided Design (CAD) and Finite Element Method (FEM) thermal and structural analysis packages were integrated with low-fidelity aero- and thermodynamic methods and high-fidelity CFD flow solvers. Analyses were characterized by the generation of an FEM unstructured grid from the CAD data, generation of a structured grid from the FEM grid, computation of the aerodynamic solution, interpolation of the flow data onto the FEM grid, and solution of the thermal and/or structural response of the geometry to the aerodynamic loading. A level of autonomy was provided by an expert system that managed the input data, selected the appropriate flow solver, and built the required input files. The ability to dynamically link available tools together to solve a given problem was also included. The framework integrated commercial tools to enable the use of distributed, heterogeneous computing systems. The framework was used to analyze the effect of wedge angle and nose radius on the heating characteristics of the nose region of a reusable launch vehicle.
An Information-Based Design Support System for Composite Structures
Authors: Hu Xiaochun , Sun Wei
Published: November 2020

This paper presents a framework of Information-Based Design Support System (IBDSS) for composite structure design, which is aiming at to improve the design process by alleviating the cost of obtaining the composite properties and the composite material design, automating design iterations in design process, and assisting to tailor material design. IBDSS mainly includes a database of composite unit cell, a reasoning and decision support module and a design and analysis module. The paper specifies problems in composite structure design, and describes the framework of the IBDSS, the logic structure of unit cell library, and its implementation in Java environment with SQL. The reasoning and decision support module with blackboard architecture and the working environment of IBDSS for Internet based design are also presented.
Steepest-Directed Tool Paths of Sculptured Parts: The Most Efficient Local Scheme in 3-Axis CNC Machining and its Mathematical Proof
Authors: Chen Zezhong C. , Dong Zuomin , Vickers Geoffrey W.
Published: November 2020

Three-axis CNC milling is often used in sculptured parts machining. Due to the complex shape of the part surfaces, optimal tool path planning can significantly improve machining efficiency. In this work the mechanism of 3-axis CNC machining is examined. The generic formulae of steepest direction of sculptured surface are derived. A mathematical proof of the highest machining efficiency of steepest-directed tool path is provided. The most efficient local scheme, steepest-directed tool path in tool path planning, is proposed. This scheme serves as a theoretical base for applying steepest-directed tool path in tool path generation algorithms for 3-axis CNC machining. The tool path has been used to develop the steepest-directed and iso-cusped (SDIC) tool path generation algorithm. An example of SDIC tool paths of a half-cylinder part illustrates the application of steepest-directed tool path.
An Algorithm to Generate Efficient Cutter Path for Pocket Milling Operations Using Modified Zigzag Strategy
Authors: Gupta Satyandra K. , Saini Sunil K. , Yao Zhiyang
Published: November 2020

Pocket milling is a widely used machining operation and used in a wide variety of applications. Using traditional zigzag milling strategy during rough milling operations, often requires several retraction or non-cutting repositioning moves, leading to poor cutting efficiency. In this paper we describe a geometric algorithm for generating cutter paths by using a modified zigzag milling strategy that attempts to minimize tool retractions and non-cutting repositioning moves. Several examples are used in the paper to show the advantage of our algorithm over traditional zigzag milling operations in rough milling of complex pockets.
A Design Procedure Applicable to Different Classes of Assemblies
Authors: Whitney Daniel E. , Shukla Gaurav , von Praun Stefan
Published: November 2020

One of the most difficult problems which designers of complex mechanical assemblies face routinely is not to be aware of when they are committing mistakes. More and more dependence of designers on CAD systems further aggravates the problem of committing the mistake of not giving proper attention to the kinematic structure of the assembly. This article presents design phases for assemblies according to a top-down design process and the generic steps that constitute different design phases. A comprehensive classification of mechanical assemblies follows the outline of the steps of the design process. This classification also defines the characteristics of different types of assemblies and most importantly it identifies the possible mistakes that designers may commit. A separate classification of different procedures for meeting assembly tolerances is also presented. This article will not only talk about the classifications but it will also enlist information about various techniques that can be used to analyze different types of assemblies. Together, these sets of classifications outline a comprehensive design procedure that will help designers of assemblies in making sure that they justify their design decisions. This paper also links the steps in the design process to specific tools developed in previous papers.
Specification of Assembly Requirements in Terms of Elementary Manipulation Tasks
Authors: Devenish Matthew D. , Rogers Graham G.
Published: November 2020

This paper presents work in progress towards a tool to assist system builders in the formal specification of lightweight, discrete component assembly tasks. Assembly system design and, in particular, manipulator design currently involves much trial-and-error testing and tends to be highly subjective. A key factor preventing the adoption of formal design methods is the lack of specification techniques for establishing and representing task requirements, such as desired pose transformation, fine motions, accuracy and compliance of the assembly manipulators. A top-down modelling framework for decomposing complex assembly manipulation tasks into elementary manipulation tasks (EMTs) is proposed. The EMT modelling approach provides the foundation for a formal CAD-based tool to represent assembly task requirements.
Optical and Mechanical Design of a Laser-Based Non-Intrusive Vehicle Delineation Detection System
Authors: Lin Bin , Cheng Harry H. , Shaw Benjamin D. , Chen Bo , Palen Joe
Published: November 2020

A field prototype of a laser-based non-intrusive vehicle detection system has been developed for measurement of delineations of moving vehicles on the highway. This prototype is based on our previous research on the principle of the measurement. The detection system uses two laser lines that are projected onto the ground as probes. The reflected light is collected and focused onto a photodiode array by an optical system. Vehicle presence is detected based on the absence of reflected laser light. By placing two identical laser/sensor pairs at a known distance apart, the speed of both the front and rear of a vehicle can be calculated based on the times when each sensor is triggered. The detector data are acquired and processed by a real-time system to obtain speed, acceleration, and length of a detected vehicle. The travel time of a vehicle can be acquired by detecting a vehicle at the beginning of a link and re-identifying the same vehicle at the end of link. Several tests have been done with the field prototype system on the highway. The testing results show that the system can obtain the accuracy of measurement necessary to distinguish between moving vehicles on the highway. This article describes the design and implementation of each functional component of an advanced version of the field prototype system.
An Intelligent Zone-Based Delivery Scheduling Approach
Authors: Wang H. , Xue D.
Published: November 2020

A zone-based delivery scheduling approach is introduced in this research using artificial intelligence techniques. In this approach, delivery scheduling is conducted at three different levels: (1) prediction of customer delivery demand using a multi-level pattern clustering and matching method, (2) creation of delivery zones based on customer delivery demand, and (3) identification of the optimal sequence and timing parameters of delivery tasks. The system was implemented using Smalltalk, an object oriented programming language.
A Computational Method for the Dynamic Analysis of Planar Linkages With Applications
Authors: Attia Hazem A.
Published: November 2020

This paper presents a computational method for generating the equations of motion of planar linkages consisting of interconnected rigid bodies. The formulation uses initially the rectangular Cartesian coordinates of an equivalent constrained system of particles to define the configuration of the mechanism. This results in a simple and straightforward procedure for generating the equations of motion. The equations of motion are then derived in terms of relative joint variables through the use of a velocity transformation matrix. The velocity transformation matrix relates the relative joint velocities to the Cartesian velocities. For the open loop case, this process automatically eliminates all of the non-working constraint forces and leads to an efficient integration of the equations of motion. For the closed loop case, suitable joints should be cut and few cut-joints constraint equations should be included for each closed loop. Examples are used to demonstrate the generality and efficiency of the proposed method.
Development of the Endo-Periscope for Improvement of Depth Perception in Laparoscopic Surgery
Authors: Breedveld Paul , Hirose Shigeo
Published: November 2020

Laparoscopic surgery is carried out by using an endoscope with a camera that is inserted through a small incision in the abdominal wall. The camera pictures are presented on a monitor. The light source of the endoscope forms a ring around the camera lens, and the endoscope movements are limited by the incision point. The absence of shadows in the camera picture and the restricted ability to observe organs from aside complicate the surgeon’s depth perception.

This paper describes the development of a new steerable endoscope that is the product of a close co-operation between the Man-Machine Systems Group of the Delft University of Technology and the Hirose & Yoneda Laboratory of the Tokyo Institute of Technology. The endoscope, which is called Endo-Periscope, uses a new spatial parallelogram-mechanism to transform the movements of the handgrip into movements of the steerable tip. The handgrip contains an arrow that points always in the direction of the line-of-sight of the tip-camera. This provides intuitive control of the tip and it shows the surgeon how the camera is oriented in the abdominal cavity. The light source is located on the shaft and the tip-camera can be moved in six degrees of freedom. This enables the surgeon to observe organs from different sides and to use shadows as a depth information source.

Part of the parallelogram-mechanism is a new kind of spring which combines a very high torsional stiffness with a low, asymmetric bending stiffness. The spring and the working principle of the Endo-Periscope have been applied for two patents.
An Approach to Computer Aided Conceptual Design of the Mechanical Products With Middle Complex Level
Authors: Xu Cheng , Wang Yongjuan , Liu Changyi
Published: November 2020

An approach synthesized with comprehensive evaluation & decision, rule-based reasoning, case-based reasoning and 3D parametric model are proposed to solve the problems of automation of the conceptual design of the mechanical products with middle complex level. A prototype software system for automatic rifle layout design was implemented using the object-oriented language — C++ based on this approach. The results running the prototype software system can well meet the demands of conceptual design of these complex level products.
A New Mathematical Model for Geometric Tolerances As Applied to Rectangular Faces
Authors: Mujezinović A. , Davidson J. K. , Shah J. J.
Published: November 2020

A new mathematical model for representing geometric tolerances is applied to rectangular faces, is extended to show its sensitivity to the precedence (ordering) of datum reference frames, and is adapted to include material modifiers. The model is compatible with the ASME/ISO Standards for geometric tolerances. Central to the new model is a Tolerance-Map©1, a hypothetical volume of points that corresponds to all possible locations and variations of a segment of a plane which can arise from tolerances on size, position, form, and orientation. Every Tolerance-Map is a convex set. This model is one part of a bi-level model that we are developing for geometric tolerances. The new model makes stackup relations apparent in an assembly, and these can be used to allocate size and orientational tolerances; the same relations also can be used to identify sensitivities for these tolerances. All stackup relations can be met for 100% interchangeability or for a specified probability. Methods are introduced whereby designers can identify trade-offs and optimize the allocation of tolerances. Examples are presented that illustrate important features of the new model.
Using a Neural Network to Determine Fitness in Genetic Design
Authors: Farritor Shane , Zhang Jun
Published: November 2020

Many automated design approaches require an objective function to determine the quality of a given design. Often, this function depends on a complex relationship between many parameters. Some parameters may be subjective and the relationships difficult to quantify.

This paper presents a method where a neural network is used to evaluate the quality of proposed designs during a genetic algorithm search. In general application of the approach, a human designer would propose candidate designs for a given problem. These candidate designs are used to train a neural network fitness function. Then the genetic algorithm evolves new designs that the human designer might not conceive. In this way, the proposed approach would aid in the brainstorming process.

The method is applied to the genetic design of modular robots for planetary exploration. This application is briefly described and the genetic design method is summarized. Then the neural network structure is explained and the training method is detailed. Finally, the neural network is used with the genetic design method to create a robot for a specific task.
Toward the Design of Compliant Actuators With a Specified Force and Stroke
Authors: Frecker Mary , Bharti Smita
Published: November 2020

The design of compliant actuators with a user-specified output stroke and force is discussed. A classical problem in structural optimization where a beam is optimally designed for a particular output deflection is investigated. This problem serves as the motivation for a scheme to scale the member sizes of an optimal compliant mechanism topology solution so that the desired output deflection is achieved. It is concluded that the scaling scheme is successful only if the stiffness of the actuator element and the external load are not considered. For the problem where a piezoceramic actuator is coupled to the compliant mechanism, which in turn works against an external spring, the optimal topology solution gives the maximum output deflection.
A General Method for Computing the Reachable Space of Mechanisms
Authors: Fuhrmann Artur , Schömer Elmar
Published: November 2020

A new methodology is presented for computing a minimal envelope for the reachable space of a mechanism, i.e. the space that contains a given mechanism in all its admissible configurations. The research is motivated by the packaging process in Digital Mock-Up applied in automotive industry. An important task in the concept phase, the automated determination of the space requirement for all parts, is still an unsolved problem in the case of mechanisms. The particular benefit of the method presented is its generality and robustness: It is able to deal with both open- and closed-loop mechanisms. The reachable space is computed with regard to the geometric description of each part. The approximation is enclosing and always converges in a uniform way and the tolerance can be pre-defined by the user. The method combines the use of bounding object hierarchies and the application of interval analysis. It is also able to approximate the swept volume of an object following a parameterized trajectory. We describe how the efficiency can be improved by lazy evaluation and by a deeper problem analysis. The presented algorithms are implemented and tested to a large extent.
On the Heuristics of Discrete Optimization
Authors: Gadallah Mohamed H.
Published: November 2020

The importance of developing optimization techniques capable of tackling realistic engineering problems cannot be underestimated. In this study, a modification to the usual Branch and Bound algorithm is presented. This modification deals with the high dimensionality of linear integer problems in three steps. The first step, statistical design of experiments is used to detect the most and least important variables. The least important variables are assigned the maximum or minimum value according to the nature of original problem. The second step, the remaining variables are assigned to an orthogonal array of proper size. The complexity of our algorithm becomes n (m – o) instead of the usual n (m). Results encouraged the extension of the developed algorithm to include continuous nonlinear problems. The nonlinear continuous problem uses the integer linear optimum solution resulted from the two stages as input for the third stage. The third stage assigns increments for the variables in a suitably chosen orthogonal array. This array is used to enumerate the optimum solution with the variations. These modifications enrich the subject of optimization through combination of search techniques and orthogonal statistical design of experiments and accommodate the problem of size. Several test cases are used to verify the performance of these modifications and conclusions are drawn.
A Meta-Object Based Approach to Finite Element Modeling
Authors: Shanbhag Santosh , Grosse Ian R. , Wileden Jack C. , Kaplan Alan
Published: November 2020

With the integration of CAD and FEA software packages, design engineers who are not skilled in finite element analysis are performing finite element modeling and analysis. Furthermore, in the analysis of a system, engineers often make numerous modeling simplifications and analysis assumptions depending on the trade-off between cost, accuracy, precision or other engineering analysis objectives. Thus, reusability or interoperability of engineering analysis models is difficult and often impractical due to the wealth of knowledge involved in the creation of such models and the lack of formal methods to codify and explicitly represent this critical modeling knowledge. Most institutions and organizations have started documenting these simplifications and assumptions, making them understandable for the other engineers within the organization. However, this does not allow a seamless exchange of data or interoperability with other analysis models of similar or dissimilar nature. This plays a very important role in today’s market, which is moving away from the traditional make-to-stock production model to a build-to-demand model. We address these issues in this paper by adopting and extending the computer science concept of meta-object, and applying it in novel ways to the domain of FEA and the representation of finite element modeling knowledge. We present a taxonomy for engineering models that aids in the definition of the various object analysis classes. A simple beam analysis example, followed by a more realistic injection-molded part example. The latter example involves injection-mold filling simulation, thermal cooling, and part ejection analyses which are subclasses for a generic manufacturing analysis meta-object class. Prototype implementations of automated support for this meta-object approach to finite element modeling is in progress.
HOME: House of Modular Enhancement for Product Redesign for Modularization
Authors: Sand J. , Gu P. , Watson G.
Published: November 2020

Product modularization aims to improve the overall design, manufacturing, operational, and post-retirement characteristics of products by designing or redesigning the product architectures. A successful modular product can assist the reconfiguration of products, while reducing the lead time of design and manufacturing and improving the ability for upgrading, maintenance, customization and recycling. This paper presents a new modular design method called the House Of Modular Enhancement (HOME) for product redesign. Information from various aspects of the product design, including functional requirements, product architecture and life cycle requirements, is incorporated in the method to help ensure that a modularized product would achieve the objectives. The HOME method has been implemented in a software system. A case study will be presented to illustrate the HOME method and the software.
Minimum Fuel Consumption and CO Emission and Optimum Speed of the Motorcycle With a CVT
Authors: Huang Yuan Mao , Hu Bi Shyang
Published: November 2020

The simulated annealing algorithm with the Bessel method for the curve fitting and the tensor product method for the surface fitting was used to transform the discrete experimental data into the form that the method of optimization can use these data directly. The rotational speeds of an engine starting the movement and corresponding the optimum speed of a motorcycle, minimum speed ratio of a CVT, optimum tooth numbers of gears and the gear ratio for the specific engine data were obtained. The rotational speeds of an engine corresponding the beginning and ending of the CVT speed ratio change, the minimum fuel consumption and the CO emission, the optimum design parameters can be determined. The results of the design parameters can be recommended for the CVT with the specific engine.
A Game-Theoretic Approach to Integrated Product Design
Authors: Steinhour William , Krishnamurthy K.
Published: November 2020

To develop a successful product in modern industry, it is necessary to incorporate design performance requirements, manufacturing processes requirements and cost considerations in the early stages of the product design cycle. In this study, a game-theoretic framework for integrated product design is discussed. A minimax game formulation is developed and applied to the design of a simplified automobile door. Results are presented with the design engineer, manufacturing engineer and cost accountant each represented by a player. The minimax game yields a conservative solution and represents the worst-case scenario. This study explores how the game-theoretic approach can be effectively implemented to design a product while satisfying conflicting requirements.
A Finite Element Approach to Direct Surface Manipulation
Authors: Marsan Anne L. , Chen Yifan , Stewart Paul
Published: November 2020

Direct surface manipulation (DSM) allows a designer to add a raised or indented feature to an existing NURBS or finite element surface. The user bounds the feature with a closed curve, and indicates an influence center that represents either the highest or lowest area of the feature. As we move radially outward from the influence center to the boundary curve, the magnitude of displacement is scaled gradually by a 1D parametric cubic basis function whose values range from 0 to 1. In this paper we present a new technique for assigning parameter values in the radial direction, i.e. u, to points within a DSM feature. The new technique poses parameter distribution as a Dirichlet problem and uses a finite element method to solve for u(x,y). The new method overcomes some stringent geometric conditions inherited from a fundamentally geometric-based reparameterization scheme and allows us to work with non-star-shaped and multiply-connected DSM features. Thus it allows us to apply this surface feature technique to a wider variety of surface applications.
Decomposition-Based Assembly Synthesis for Maximum Structural Strength and Modularity
Authors: Cetin Onur L. , Saitou Kazuhiro
Published: November 2020

This study presents a systematic decomposition process to carry out assembly synthesis as a tool during the conceptual design phase of a product. Two configurations obtained by structural topology optimization are decomposed automatically into assemblies consisting of multiple members with simpler geometries. The optimal decomposition can be posed as a graph partitioning problem, which is actually a discrete optimization task. Considering the nonlinearity and the corresponding computational overhead of the problem, a steady-state genetic algorithm is employed as the optimization method. The final objective function attempts to find a solution that brings about two structures with maximum structural strength, maximum assemblability, and one or more components that can be shared by both products. The software implementation is carried out and a typical problem is solved using the procedure. It is observed that the algorithm manages to find an acceptable solution, allowing the commonality of one component in both end products and still maintaining a good structural strength and assemblability.
Successive Twinkling Simplex Search Optimization Algorithms
Authors: Mekhilef Mounib , Trabia Mohamed B.
Published: November 2020

Simplex algorithms have been proven to be a reliable nonlinear programming pattern search algorithm. The effectiveness of simplex however reduces when the solved problem has large number of variables, several local minima, or when initial guess is not readily available. Recent results obtained by introducing a technique of random selection of the variables in optimization processes, encouraged studying the effect of this idea on the Nelder & Mead version of the simplex algorithm to improve its semi-global behavior. This paper proposes several enhancements to the simplex. The algorithm is run for several attempts. Each attempt uses the final answer of the previous attempt as an initial guess. At each attempt, the search starts by generating a simplex with n+1 vertices. A random subset of the variables is involved in the movement (reflection, expansion, contraction, shrinking) of the simplex. This process is called twinkling. The paper presents several variations of twinkling the simplex. The random nature of the algorithm lends itself to problems with large dimensionality or complex topography. The algorithm is applied successfully to several engineering design problems. The results compare favorably with both regular simplex and genetic algorithms.
Optimization of the Closure-Weld Region of Cylindrical Containers for Long-Term Corrosion Resistance
Authors: Ceylan Zekai , Trabia Mohamed B.
Published: November 2020

Welded cylindrical containers usually experience stress corrosion cracking (SCC) in the closure-weld area. Induction coil heating technique may be used to relieve the residual stresses from the closure-weld. This technique involves localized heating of the material by the surrounding coils. The material is then cooled to the room temperature by quenching. A two-dimensional axisymmetric finite element model is developed to study the effects of induction coil heating and subsequent quenching. The finite element results are validated through an experimental test. The parameters of the design are tuned to maximize the compressive stress within a layer of thickness from the outer surface that is equal to the long-term general corrosion of Alloy 22 (Appendix A). The problem is subject to geometrical and stress constraints. Two different solution methods are implemented for this purpose. First, an off-the-shelf optimization software is used to obtain an optimum solution. These results are not satisfactory because of the highly nonlinear nature of the problem. The paper proposes a novel alternative: the Successive Heuristic Quadratic Approximation (SHQA) technique. This algorithm combines successive quadratic approximation with an adaptive random search. Examples and discussion are included.
Improvement on the Adaptive Response Surface Method for High-Dimensional Computation-Intensive Design Problems
Authors: Wang G. Gary
Published: November 2020

This paper addresses the difficulty of the previously developed Adaptive Response Surface Method (ARSM) for high-dimensional design problems. The ARSM was developed to search for the global design optimum for computation-intensive design problems. This method utilized the Central Composite Designs (CCD), which resulted in an exponentially increasing number of required design experiments. In addition, the ARSM generates a complete new set of CCDs in a gradually reduced design space. These two factors greatly undermine the efficiency of the ARSM. In this work, the Latin Hypercube Designs (LHD) were utilized to generate saturated design experiments. Because of the use of Latin Hypercube Designs, the historical design experiments can be inherited in later iterations. The improved ARSM has been tested using a group of standard testing problems and then applied to an engineering design. In both testing and design application, significant efficiency improvement of the ARSM was observed. The ARSM at the current stage demonstrated strong potential to be an efficient global optimization tool for computation-intensive design problems.
View-Dependent Deformation With Sketching Input
Authors: Wang Charlie C. L. , Yuen Matthew M. F.
Published: November 2020

The primary objective of this research work is to develop an efficient and intuitive deformation tool for conceptual freeform geometric modeling by sketching input. With our method, the user can sketch two strokes called the reference stroke and the target stroke to modify the model. The system moves the vertices of the polygonal model so that the spatial relation between the original positions and the reference stroke is identical to the relation between the resulting position and the target stroke. The movement is perpendicular to the view direction, and vertices do not move in the view direction. Thus, deform a object from different view direction will lead to different result — called view-dependent deformation. Our method is related to axial deformation. The self-intersection problem is solved, and users can define influence region by our deformation tool.
Optimal Concurrent Design Based Upon Distributed Database and Knowledge Base Modeling
Authors: Zhang F. , Xue D.
Published: November 2020

This research introduces an optimal concurrent design approach based upon a previously developed distributed database and knowledge base modeling method. In this approach, the product realization process alternatives and relevant activities are modeled at different locations that are connected through the Internet. The optimal product realization process alternative and its parameter values are identified using a multi-level optimization method. Genetic Programming (GP) and Particle Swarm Optimization (PSO) are employed for identifying the optimal product realization process alternative and the optimal parameter values of the feasible alternatives, respectively.
An Approach to Sweeping NURBS
Authors: Yang Jingzhou , Abdel-Malek Karim , Cremer Jim
Published: November 2020

This paper presents a method of determining the swept volume of Non-Uniform rational B-Spline (NURBS) curves and surfaces. Characteristic (also called singular) points or curves are determined by obtaining local and global maxima points at discrete frames during the motion and with respect to a local moving coordinate system. This coordinate system is calculated in reference to the direction of motion of the rigid body as determined from its composite velocity vector. The aim is to develop a rigorous method for identifying and visualizing a NURBS swept volume. NURBS have become the industry standard for the representation, design, and data exchange of geometric information processed by computers. On the other hand, sweeping operations are valuable tools for the CAD user to shape and create primitives. In this paper, we extend our previous method used in determining the swept volume of implicit and parametric surfaces and those that are as a result of multiple sweeping. The method and numerical algorithm are illustrated through examples.
Design Parameterization for Concurrent Design and Manufacturing of Mechanical Systems
Authors: Chang Kuang-Hua , Silva Javier
Published: November 2020

Design changes are frequently encountered in the product development process. The complexity of the design changes is multiplied when the product design involves multiple engineering disciplines. Very often, a simple change in one part may propagate to its neighboring parts, therefore, affects the entire product assembly. Both parts and assembly must be regenerated for a physically valid product model, at the same time, the regenerated product model must meet designer’s expectations.

When a product is being developed in a Concurrent Design and Manufacturing (CDM) environment, the design changes are usually implemented first by altering geometry of the product represented in computer-aided design (CAD) solid models. If the product solid model is not parameterized properly, the changes in geometry often lead to invalid parts or assembly. At the part level, the changes may yield a solid model with invalid geometric features if it is not properly parameterized. In this case, the entire product assembly is in vain. Even when individual parts of the product are regenerated correctly, parts may still penetrate to their neighboring parts or leave excessive gaps among them, if the solid model is not properly parameterized at the assembly level.

In this paper, solid modeling and assembly techniques implemented in two major CAD tools, Pro/ENGINEER and SolidWorks, will be discussed. A set of guidelines will be proposed for the designers to parameterize the solid models in order to capture the design intents more effectively in the product virtual mockup. These guidelines at both part and assembly levels will support designers to successfully conduct product design in the CDM environment.

A number of examples, including a slider-crank mechanism and its crankshaft, a single-piston airplane engine and its components, as well as a number of simpler parts are presented to illustrate and demonstrate the parameterization method and guidelines proposed for both Pro/ENGINEER and SolidWorks.
Process Planning in Layer-Based Machining
Authors: Yang Z. Y. , Chen Y. H.
Published: November 2020

Some freeform surfaces cannot be machined by traditional CNC machining because of the inaccessibility to some critical points. Layer-based machining system developed by the authors can enlarge the accessibility by building a model layer by layer. Each layer is shaped by 5-axis machining. In this paper, the overall process planning techniques are identified and analyzed. The data flow chart in layer-based machining is established. The concepts of “decomposition for accessibility” and “decomposition for manufacturability” are proposed to decompose the model into manufacturable parts, which is called slabs. Adaptive slicing and interference avoidance algorithms are developed to achieve the maximum accessibility. A method called stock layer combination is proposed to select available stock layers for the process.
Haptic and Aural Rendering of a Virtual Milling Process
Authors: Chang Chu-Fei , Varshney Amitabh , Ge Q. J.
Published: November 2020

This paper deals with the development of a multisensory virtual environment with visual, haptic, and aural feedbacks for simulating the five-axis CNC milling process. The paper focuses on the haptic and aural rendering of the virtual milling process. Haptic rendering provides the user with kinesthetic and tactile information. Kinesthetic information is displayed by the cutting force of a milling machine. The tactile information is conveyed by the haptic texturing. Aural rendering simulates the machine sound and provides the aural feedback to the user. Using ideas from the concepts of image-based rendering, haptic and aural rendering are accelerated by pre-sampling related environment’s parameters in a perception-dependent way.