Technique of Extrusion Die Tolerance Analysis Based on CAT

2014 ◽  
Vol 941-944 ◽  
pp. 1777-1781
Author(s):  
Yuan Lou Gao ◽  
Zhe Li ◽  
Xin Wang
Keyword(s):  
Manufacturing Process ◽  
Tolerance Analysis ◽  
Chemical Characteristics ◽  
Tolerance Design ◽  
Generation Algorithm ◽  
Extrusion Die ◽  
Tolerance Modeling ◽  
Screw Extrusion ◽  
Computer Aided ◽  
Manual Calculation

As traditional screw extrusion die tolerance analysis has characteristics like manual calculation, experience dependence so far, this paper aims at applying CAT (Computer Aided Tolerancing) into extrusion field with the assistance of tolerance modeling and self-generation algorithm of retrieval dimension chain to analyze tolerance and reassign tolerance based on the technology used for aircraft assembly referring to chemical characteristics of the manufacturing process. Practice on production line testified the rationality of improved tolerance design.

Computer-Aided Monte Carlo Aircraft Tolerance Design Based on UG

2011 ◽  
Vol 338 ◽  
pp. 300-303
Author(s):  
Chang Hong Guo ◽  
Ping Xi ◽  
Zhen Yu Wang ◽  
Xing Dong Li
Keyword(s):  
Monte Carlo ◽  
Three Dimensional ◽  
Integrated Design ◽  
Tolerance Analysis ◽  
Digital Design ◽  
Tolerance Design ◽  
Computer Aided ◽  
Design And Manufacture

Along with the CAD technology being popularized, three-dimensional design of aircraft is ultimately realized into digital design. However, aircraft tolerances have not been designed by computer. They are mainly based on lots of manual calculations and not coordinated with integrated design and hold back the development of aircraft digital design and manufacture technologies. This paper introduces how to develop computer-aided aircraft tolerance analysis and distribution modules on UG and introduces Monte Carlo tolerance analysis technology. Running instances of aircraft tolerance design are illustrated in the paper.

Fuzzy Tolerance Analysis of 3-D Mechanical Assemblies

1997 ◽  
Author(s):  
K. Srikanth ◽  
F. W. Liou ◽  
S. N. Balakrishnan
Keyword(s):  
Fuzzy Logic ◽  
Manufacturing Process ◽  
Three Dimensional ◽  
Tolerance Analysis ◽  
Tolerance Design ◽  
Cost Information ◽  
Assembly Tolerance ◽  
Mechanical Assemblies ◽  
Representation Scheme ◽  
Tolerance Assignment

Abstract Tolerance design is interdisciplinary in nature and is characterized by a highly uncertain environment. In recent years, fuzzy logic has appeared as a credible alternative for tolerance design. In this paper a fuzzy based tolerance representation scheme is presented to model three dimensional (3-D) tolerances. With this representation, relative assembly tolerance constraints can be expressed. A fuzzy tolerance generation and assignment process for assembly is discussed. Fuzzy tolerance equations are generated for 3-D assembly considerations. Manufacturing process information, along with uncertain cost information modeled in fuzzy terms, is added to the system to arrive at a cost-optimal tolerance assignment.

Machining Feature-Based CAD/CAPP for STEP-NC

2014 ◽  
Vol 598 ◽  
pp. 591-594 ◽  
Author(s):  
Li Yan Zhang
Keyword(s):  
Process Planning ◽  
Manufacturing Process ◽  
Data Transfer ◽  
Operation Planning ◽  
Computer Aided Process Planning ◽  
Machining Feature ◽  
Computer Aided ◽  
Cad Cam ◽  
Feature Based ◽  
Cam Systems

ISO 14649, known as STEP-NC, is new model of data transfer between CAD/CAM systems and CNC machines. In this paper, the modeling based on machining feature is proposed. The machining feature comes from the manufacturing process considering the restriction of machining technology and machining resource. Then the framework for computer aided process planning is presented, where the algorithms of operation planning is studied. The practical example has been provided and results indicate that machining feature based model can integrate with CAPP and STEP-NC seamlessly.

Conformal Optimization Algorithm for Undevelopable Surfaces and its Application

2014 ◽  
Vol 602-605 ◽  
pp. 3570-3574
Author(s):  
Zhen Hua Luo ◽  
Fen Jiang
Keyword(s):  
Approximation Algorithms ◽  
Optimization Algorithm ◽  
Manufacturing Process ◽  
Research Topic ◽  
Important Research ◽  
Computer Aided Geometric Design ◽  
Industrial Manufacturing ◽  
Important Research Topic ◽  
Computer Aided ◽  
Planar Materials

In the industrial manufacturing process, most kinds of surfaces are processed by planar materials, but undevelopable surfaces are difficult develop to the plane. The approximation algorithms to develop a undevelopable surface is an important research topic in Computer Aided Geometric Design (CAGD). In this paper, we propose a new approximation algorithms based optimization algorithm. We guarantee the deformation vector make the minimum changes during the developing process. In the paper, some numerical example are given and the can illustrate the our method is effective.

Process Signature Modeling for Tolerance Analysis

2010 ◽  
Vol 10 (2) ◽  
Author(s):  
R. Ascione ◽  
W. Polini ◽  
Q. Semeraro
Keyword(s):  
Concurrent Engineering ◽  
Manufacturing Process ◽  
Tolerance Analysis ◽  
Actual Surface ◽  
Contact Points ◽  
Geometric Tolerances ◽  
Systematic Pattern ◽  
Process Signature ◽  
Nominal Surface

Many well-known approaches exist in the literature for tolerance analysis. All the methods proposed in the literature consider the dimensional and the geometric tolerances applied to some critical points (contact points among profiles belonging to couples of parts) on the surface of the assembly components. These points are generally considered uncorrelated since the nominal surface is considered. Therefore, the methods proposed in the literature do not consider the actual surface due to a manufacturing process. Every manufacturing process leaves on the surface a signature, i.e., a systematic pattern that characterizes all the features machined with that process. The aim of the present work is to investigate the effects of considering the manufacturing signature in solving a tolerance stack-up function. A case study involving three parts has been defined and solved by means of a method of the literature, the variational method, with and without considering the correlation among the points of the same surface due to the manufacturing signature. This work represents a first step toward the integration of the design and the manufacturing in a concurrent engineering approach.

Parametric Kinematic Tolerance Analysis of Planar Pairs With Multiple Contacts

1996 ◽  
Author(s):  
Elisha Sacks ◽  
Leo Joskowicz
Keyword(s):  
Efficient Algorithm ◽  
Tolerance Analysis ◽  
Parametric Model ◽  
Worst Case ◽  
Multiple Contacts ◽  
Work Cycle ◽  
Computer Aided ◽  
Kinematic Models ◽  
Range Of Variation ◽  
Different Parts

Abstract We present an efficient algorithm for worst-case limit kinematic tolerance analysis of planar kinematic pairs with multiple contacts. The algorithm extends computer-aided kinematic tolerance analysis from mechanisms in which parts interact through permanent contacts to mechanisms in which different parts or part features interact at different stages of the work cycle. Given a parametric model of a pair and the range of variation of the parameters, it constructs parametric kinematic models for the contacts, computes the configurations in which each contact occurs, and derives the sensitivity of the kinematic variation to the parameters. The algorithm also derives qualitative variations, such as under-cutting, interference, and jamming. We demonstrate the algorithm on a 26 parameter model of a Geneva mechanism.

Automated Reuse of Solutions in Manufacturing Process Planning Through a Case-Based Approach

1996 ◽  
Author(s):  
M. Marefat ◽  
J. Britanik
Keyword(s):  
Process Planning ◽  
Manufacturing Process ◽  
Object Oriented ◽  
Process Plan ◽  
Primary Mechanism ◽  
Prismatic Parts ◽  
Manufacturing Process Planning ◽  
Computer Aided ◽  
Effective Use ◽  
Case Based

Abstract This research focuses on the development of an object-oriented case-based process planner which combines the advantages of the variant and generative approaches to process planning. The case-based process planner operates on general 3D prismatic parts, represented by a collection of features (eg: slots, pockets, holes, etc.). Each feature subplan is developed by the case-based planner. Then the feature subplans are combined into the global process plan for the part via a hierarchical plan merging mechanism. Abstracted feature subplans correspond to cases, which are used in subsequent planning operations to solve new problems. The abstracting and storing of feature subplans as cases is the primary mechanism by which the planner learns from its previous experiences to become more effective and efficient. The computer-aided process planner is designed to be extensible and flexible through the effective use of object-oriented principles.

Constraints and limitations of concrete 3D printing in architecture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chien-Ho Ko
Keyword(s):  
3D Printing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Research Approach ◽  
Layer By Layer ◽  
Content Type ◽  
Improve Design ◽  
Study Results ◽  
Computer Aided ◽  
Property Control

Purpose Additive manufacturing of concrete (AMoC) is an emerging technology for constructing buildings. However, due to the nature of the concrete property and constructing buildings in layers, constraints and limitations are encountered while applying AMoC in architecture. This paper aims to analyze the constraints and limitations that may be encountered while using AMoC in architecture. Design/methodology/approach A descriptive research approach is used to conduct this study. First, basic notions of AMoC are introduced. Then, challenges of AMoC, including hardware, material property, control and design, are addressed. Finally, strategies that may be used to overcome the challenges are discussed. Findings Factors influencing the success of AMoC include hardware, material, control methods, manufacturing process and design. Considering these issues in the early design phase is crucial to achieving a successful computer-aided design (CAD)/computer-aided manufacturing (CAM) integration to bring CAD and CAM benefits into the architecture industry. Originality/value In three-dimensional (3D) printing, objects are constructed layer by layer. Printing results are thus affected by the additive method (such as toolpath) and material properties (such as tensile strength and slump). Although previous studies attempt to improve AMoC, most of them focus on the manufacturing process. However, a successful application of AMoC in architecture needs to consider the possible constraints and limitations of concrete 3D printing. So far, research on the potential challenges of applying AMoC in architecture from a building lifecycle perspective is still limited. The study results of this study could be used to improve design and construction while applying AMoC in architecture.

CATI: A Computer Aided Tolerancing Interface

1992 ◽  
Author(s):  
Rikard Söderberg
Keyword(s):  
Normal Distribution ◽  
Tolerance Analysis ◽  
Distribution Model ◽  
Preliminary Design ◽  
Tolerance Limits ◽  
Cad System ◽  
System A ◽  
Computer Aided ◽  
2D Drawing ◽  
Normal Distribution Model

Abstract This work presents an interface for tolerance analysis in a CAD system. A method for picking up necessary information from a 2D drawing is developed and implemented as an interface in a commercial CAD system. The interface communicates with an external calculation program which determines unknown tolerance limits using the normal distribution model. Results from the calculation program is in the end used by the interface to present measures with tolerances on the drawing. The advantage of using CATI in preliminary design is discussed, and a strategy for treating interrelated tolerance chains is presented.

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