A Complete Variation Algorithm for Slot and Tab Features for 3D Simulation-Based Tolerance Analysis

2005 ◽  
Author(s):  
Zhengshu Shen ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Tolerance Analysis ◽  
Virtual Manufacturing ◽  
3D Simulation ◽  
Product Development Process ◽  
Simulation Tools ◽  
Geometric Dimensioning And Tolerancing ◽  
Material Condition ◽  
Tolerance Chart ◽  
Simulation Based ◽  
Mechanical Products

Development of tolerance analysis methods that are consistent with the ASME and ISO GD&T (geometric dimensioning and tolerancing) standards is a challenging task. Such methods are the basis for creating computer-aided tools for 3D tolerance analysis and assemblability analysis. These tools, along with the others, make it possible to realize virtual manufacturing, in order to shorten lead-time and reduce cost in the product development process. Current simulation tools for 3D tolerance analysis and assemblability analysis are far from satisfactory because the underlying variation algorithms are not fully consistent with the GD&T standards. Better algorithms are still to be developed. Towards that goal, this paper proposes a complete algorithm for 3D slot features and tab features (frequently used in mechanical products) for 3D simulation-based tolerance analysis. The algorithms developed account for bonus/shift tolerances (i.e. effects from material condition specifications), and tolerance zone interaction when multiple tolerances are specified on the same feature. A case study is conducted to demonstrate the algorithm developed. The result from this work is compared with that from 1D tolerance chart method. The comparison study shows quantitatively why 1D tolerance chart method, which is popular in industry, is not sufficient for tolerance analysis, which is 3D in nature.

Simulation-Based Tolerance and Assemblability Analyses of Assemblies With Multiple Pin/Hole Floating Mating Conditions

2005 ◽  
Author(s):  
Zhengshu Shen ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Tolerance Analysis ◽  
Virtual Manufacturing ◽  
Product Development Process ◽  
3D Analysis ◽  
Dimensional Problem ◽  
Press Fit ◽  
Simulation Based ◽  
The Difference ◽  
2D And 3D ◽  
Mating Conditions

Development of tolerance analysis methods that are consistent with the ASME and ISO GD&T (geometric dimensioning and tolerancing) standards is a challenging task. Such methods are the basis for creating computer-aided tools for 3D tolerance analysis and assemblability analysis. These tools, along with the others, make it possible to realize virtual manufacturing in order to shorten lead-time and reduce cost in the product development process. Current simulation tools for 3D tolerance analysis and assemblability analysis are far from satisfactory because the underlying variation algorithms are not fully consistent with the GD&T standards. Better algorithms are still to be developed. Towards that goal, this paper proposes an improved simulation-based approach to tolerance and assemblability analyses for assemblies with pin/hole floating mating conditions in mechanical products. A floating pin/hole mating condition is the one where the mating pin should be able to “float” within the mating hole, and thus press-fit is not necessary for the parts to assemble properly. When multiple pin/hole mating pairs are involved in a product, the feasibility of assembly needs to be analyzed. This paper will introduce a more complete method of analyzing assemblability for such assemblies. In most cases, a 3D (3-dimensional) problem can be simplified to 1D (1-dimensional) or 2D (2-dimensional) problem, with the loss of some accuracy. To make a comparison and find out how accurately 1D and 2D analyses can approximate 3D analysis, this paper will provide the variation algorithms for 1D, 2D and 3D simulations. The algorithms developed account not only for bonus/shift tolerances but also for feasibility of assembling. These algorithms are extendable to consider other different GD&T specifications. The assemblability criteria proposed is generally applicable to any assemblies with pin/hole floating mating conditions. Case studies are provided to demonstrate the algorithms developed. The comparison study shows quantitatively the difference in the results from 1D, 2D and 3D simulation based analyses.

Preliminary Investigation on Generating an Explicit GD&T Scheme From a Process Plan

2013 ◽  
Author(s):  
Payam Haghighi ◽  
Prabath Vemulapalli ◽  
Prashant Mohan ◽  
Jami J. Shah ◽  
Joseph K. Davidson
Keyword(s):  
Reference Frames ◽  
Preliminary Investigation ◽  
Tolerance Analysis ◽  
Research Issues ◽  
Geometric Dimensioning And Tolerancing ◽  
Implicit Information ◽  
Material Condition ◽  
Geometric Tolerances ◽  
Manufacturing Tolerances ◽  
Set Up

Geometric Dimensioning and Tolerancing (GD&T) Standards have established a language for clear and concise specification of dimensional and geometric variations on manufactured parts. The language includes symbols for tolerance type, tolerance value, datum and reference frames, diameter and material condition modifiers and associativity with geometric entities. Designers use the standard to communicate their dimensional specifications to manufacturing and inspection personnel. However, process planners appear to be less formal in how tolerances are represented in process plans. Typically, they are shown only as dimensional plus/minus values. Datum Reference Frames (DRF) and geometric tolerance symbols are absent. It is believed that the latter are implicit in the set-up and fixturing prescribed in the plan. In this paper we explore how one might extract the implicit information systematically. The motivation for this effort is to verify the consistency of manufacturing tolerances with design specs and to be able to use the same tolerance analysis tools used in design. We discuss three research issues: extracting implied DRFs from set-ups and fixtures; converting plus/minus tolerances to appropriate geometric tolerances; and dealing with transient features — which are features that do not exist on the finished part used for GDT specs by the designer. We propose a new data structure, PCTF (process oriented constraint tolerance feature graph) to facilitate mapping between design and manufacturing tolerances.

Investigating the Effect of 3D Simulation Based Learning on the Motivation and Performance of Engineering Students

2010 ◽  
Vol 99 (3) ◽  
pp. 237-251 ◽  
Author(s):  
Caroline Koh ◽  
Hock Soon Tan ◽  
Kim Cheng Tan ◽  
Linda Fang ◽  
Fook Meng Fong ◽  
...  
Keyword(s):  
Engineering Students ◽  
3D Simulation ◽  
Simulation Based ◽  
And Performance

Sensitivity Analysis of Relative Worth in Empirical and Simulation-Based QFD Matrices

2008 ◽  
Author(s):  
Robins M. Kalapurackal ◽  
Shun Takai
Keyword(s):  
Cost Reduction ◽  
Quality Function Deployment ◽  
Development Process ◽  
Rating Scales ◽  
Rating Scale ◽  
Calculation Scheme ◽  
Product Development Process ◽  
Customer Requirements ◽  
Design Changes ◽  
Simulation Based

Quality function deployment (QFD) is one of the most popular tools used in the product development process. It relates customer requirements to product requirements and enables engineers to determine which product requirement is more important than the others in satisfying customers. Some of the benefits of QFD are cost reduction, fewer design changes at the start of production, and improved communication among engineers. QFD applications use various approaches (i.e., worth calculation schemes and rating scales) to calculate the worth of requirements. The purpose of this paper is to study the change in the relative worth (normalized worth) of product requirements yielded by different rating scales and calculation schemes. We studied empirical and simulation-generated QFD matrices to determine how calculation schemes and rating scales influence the relative worth of requirements. Two representative scales and two calculation schemes are used to find the most and least sensitive cases, and the influence of the number of rows and columns in the relative worth of requirements. From the results, we identified the least sensitive and most sensitive combination of calculation scheme and rating scale. We also learned that QFD matrices become less sensitive to changes in rating scale and calculation scheme as the number of columns increases.

Categorized Application Technology of Numerical Simulation on Electronic Equipment Thermal Design

2009 ◽  
Author(s):  
Yasuyuki Yokono ◽  
Katsumi Hisano ◽  
Kenji Hirohata
Keyword(s):  
Numerical Simulation ◽  
Product Development ◽  
Statistical Approach ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Product Development Process ◽  
Design Stage ◽  
Application Technology ◽  
Simulation Techniques ◽  
Simulation Based

In order to utilize a numerical simulation on a product development for electronic equipment, not only the simulation techniques themselves, but the application technologies of the simulation in the product design, were examined. The design process of electronic equipment was categorized into four stages, which were a concept, a function, a layout and a parameter design. Each design stage consists of a specifying that a human decide the specification for the next stage and a verification whether the specification satisfy the previous stage requirements. The specifying and the verification are conducted over and over again. Numerical simulation is corresponded to the verification and is used to accelerate this iteration instead of experiments. The examples of numerical simulation corresponding to these four verifications were shown in the present paper. There are few examples in last two type of simulation. The progress of the numerical technology for function and concept verification is expected. The product development process requires not only numerical simulation based on physics but also statistical approach.

Project-based strategy for teaching photovoltaic considering 3D simulation tools and natural phenomena

2019 ◽  
pp. 002072091986040 ◽  
Author(s):  
J Miguel Gonzalez ◽  
Joel Salome Baylon ◽  
Eric Morales Aguilar ◽  
Ramon O Betancourt ◽  
Luis A Contreras Aguilar ◽  
...  
Keyword(s):  
3D Simulation ◽  
Natural Phenomena ◽  
Simulation Tools

A framework for applying simulation in construction

1998 ◽  
Vol 25 (3) ◽  
pp. 604-617 ◽  
Author(s):  
Simaan M AbouRizk ◽  
Dany Hajjar
Keyword(s):  
Visual Object ◽  
Successful Implementation ◽  
Construction Operations ◽  
Construction Firms ◽  
Simulation Tools ◽  
Construction Companies ◽  
The Past ◽  
Simulation Based ◽  
Research Environments ◽  
Process Interaction

Researchers have successfully implemented system simulation concepts for the design and analysis of construction operations over the past two decades. A number of simulation environments have been created mostly following the CYCLONE methodology introduced by Halpin. The successes, however, remain limited to the academic and research environments. Construction companies have yet to demonstrate acceptance of simulation for everyday decision making. In this paper, an approach is presented that will facilitate adoption of simulation by industry. It summarizes five years of close work with a number of construction firms in developing and implementing simulation-based tools at their organizations. The paper also provides an overview of three simulation implementations for an earth moving contractor, an aggregate producer, and a general contractor. The three implementations represent different "world views" of simulation, namely (i) dynamic process interaction, (ii) continuous time-dependent, and (iii) static simulation. The successful implementation of these simulation tools was based on a common visual-object-oriented modeling environment. The successes, failures, and challenges of these implementations are also discussed.Key words: computer modeling, computer simulation, special purpose simulation.

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