الفهرس 
Introduction and Literature ReviewOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
Designers are frequently called upon to assign dimensional and geometrical tolerances to components and assemblies such that their manufacture is both feasible and economical and that products made of these components will function satisfactority. Interchangeable parts and the reduction of manufacturing costs are the motivation for considering carefully design tolerance allocation and improve methods for products error evaluation
Due to the increasing demands for better performance of manufactured parts, new trends in geometrical tolerancing and error evaluation methods are needed. These methods should take the actual part’s performance in direct consideration to obtain a truly complete surface characterization of the part. This characterization should insure the best possible performance through a minimum number of allocated tolerances in order to reduce allocation and evaluation time and efforts. This concepts can only be arrived at through the implementation of the whole geometry concept
For the purpose of product error evaluation, the concept of whole geometry is introduced, which can be stated as the complete types of relations between the different geometric features of the part which could be created during its manufacturing, during assembly of different part, and during functioning. Whole part geometry evaluation measurably improves the functional performance, interchangeable parts and ease of part of part assembly. The analysis of the part’s whole geometry will result into the determination of the aloowable limits of size of each part of the mechanical system to obtain the required function accurately and precisely
The concept of whole geometry states that there is a relation between the various geometrical errors and therefore there is no need to measure the values of each required error independently, whereas it is possible to obtain the value of a number of geometrical errors through the measurement of one single error. In other words, when we are faced with a part with multiple features and it is required to evaluate the various geometrical errors associated withthese features, it is sufficient to problem a number of measurements that is significantly less than is usually carried out