摘要:

The Computer Numerical Control (CNC) machine is one of the most effective production facilities used in manufacturing industry. Determining the optimal machining parameters is essential in the machining process planning since the machining parameters significantly affect production cost and quality of machined parts. Previous studies involving machining optimization of turning operations concentrated primarily on developing machining models for bar components. Machined parts on the CNC lathes, however, typically have continuous forms. In this study, we formulate an optimization model for turned parts with continuous forms. Also, a stochastic optimization method based on the simulated annealing algorithm and the pattern search is applied to solve this machining optimization problem. Finally, the applications of the developed machining model and the proposed optimization algorithm are established through the numerical examples.

ISSN:0740-817X    

DOI:10.1080/07408179908969861

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this paper we describe the architecture of a new integrated process planning system, called 31-PP, which is comprised of three modules: feature completion, process selection, and process sequencing. We have applied a knowledge-based approach to feature completion and process selection, and the space search algorithm for process sequencing. The resulting process planning system provides for both upstream and downstream integration of CAPP with CAD and scheduling systems, rej.pectively. Description of the methodologies and procedures is provided and some experimental results that demonstrate the system performance are presented.

ISSN:0740-817X    

DOI:10.1080/07408179908969862

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper presents an optimization approach for evaluating the minimum zone flatness for a data set obtained from a Coordinate Measuring Machine. The search for the minimum zone is performed in the parameter space of a plane. The perpendicular distance (p) from the origin to a normal plane intersecting each point in the data set is determined. The difference between the maximum ‘p’ and the minimum ‘p’ for a particular set of parameters (direction cosine angles) determines the minimum zone for flatness. The parameters defining the orientation of a plane through each point in the data set are searched systematically. The set of parameters that determine the minimum zone is found by simplex search. The new method is applied to six example data sets and the results are compared with other methods.

ISSN:0740-817X    

DOI:10.1080/07408179908969863

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A successful approach to the generation of quadrilateral surface meshes for finite element analysis of sculptured surface products is presented. The free-form sculpted surface is divided into a feature based product anatomy which is used as the basis for defining regions of simpler shape that are related by the requirement for mesh continuity across their boundaries. Each surface region is meshed using a paving algorithm. Large surface areas are further subdivided to introduce new boundaries which improve contiol over mesh transitions and element distortion. A procedure, based on this approach, which generates well formed meshes on sculptured surface products is described using a hollow golf club head as an example. The approach is product specific and relies on initial user interaction to populate a feature based product data model. Thus, the data model contains, the attributes of a finite element mesh tailored to the product, which can be used to generate meshes on subsequent design iterations or other members of the product family with a high degree of automation, leading to reduced analysis cost.

ISSN:0740-817X    

DOI:10.1080/07408179908969864

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper addresses the problem of minimizing the amount of wasted space when cutting a set of rectangular pieces from a single rectangular sheet of stock material. A simulated annealing algorithm is developed and is shown to significantly outperform three existing heuristics on a set of 37 real-world data sets. In addition, a mathematical programming formulation of the problem and several theoretical lower bounds are developed and used to demonstrate that the simulated annealing solutions are within 9.5% of the optimal solution, on average.

ISSN:0740-817X    

DOI:10.1080/07408179908969865

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This research deals with the problems of setup and fixture planning for the machining of prismatic parts. The overall aim is to design the minimum number of setups that can be fixtured and machined using the available fixture elements and tools on the shop-floor. Setup planning takes into account machining sequence constraints, machine tools, as well as the feasibility of fixturing. A general scheme for search strategies in such planning is developed and implemented. The greater part of this work is aimed towards the development of an automatic fixture planner. A generalized representation scheme for a variety of fixture elements using geometric as well as functional properties is developed. A methodology is described to build up assemblies of fixture elements complete with the workpiece. The proposed approach has been implemented as part of an existing automated process planning system called the Quick Turnaround Cell.

ISSN:0740-817X    

DOI:10.1080/07408179908969866

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper presents an approach to the development of an open collaborative design environment in the Computer Aided Design (CAD) setting of a networked enterprise. Demand for high quality and variety of low to medium quality of products or 'mass customization' has led to the concept of'virtual organizations'. The de-centralized design teams of such an organization require a framework to manage the CAD product information. By integrating the emerging standard for 3D geometry on the World Wide Web with conventional CAD packages, we describe a framework for the development of a product model with various levels of abstractions. The syntactic content of the product model, accessible through any Internet interface such as Netscape Navigator associates itself with a centralized database for embedding technological information at the face and feature levels. The semanlic and syntactic content of the product model can then be accessed and manipulated through the single Internet interface. The system is deployed on a test-bed utilizing both a UNIX box and a machine operating under the Windows NT system, to demonstrate it's open architecture and interoperability.

ISSN:0740-817X    

DOI:10.1080/07408179908969867

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This paper considers the problem of minimizing the fixed cost of acquiring material handling transporter:; and the operational cost of material transfer in a manufacturing system. This decision problem, which arises during manufacturing facility design, is modeled using an integer programming formulation. Since the problem isNP-complete, two efficient heuristics are developed to solve it. Computational complexity, worst-case performance analysis, and extensive computational tests are provided for both heuristics. The results indicate that the proposed methods are well suited for large-scale manufacturing applications.

ISSN:0740-817X    

DOI:10.1080/07408179908969868

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor