Direct tolerance analysis of mechanical assemblies with normal and non-normal tolerances for predicting product quality

2022 ◽  
pp. 1-18
Author(s):  
H. Hassani ◽  
S. Khodaygan
Keyword(s):  
Product Quality ◽  
Tolerance Analysis ◽  
Mechanical Assemblies

Statistical Tolerance Analysis of Over-Constrained Mechanical Assemblies With Form Defects Considering Contact Types

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Edoh Goka ◽  
Lazhar Homri ◽  
Pierre Beaurepaire ◽  
Jean-Yves Dantan
Keyword(s):  
Tolerance Analysis ◽  
Optimization Methods ◽  
Optimization Techniques ◽  
Behavior Modeling ◽  
Functional Requirements ◽  
Mechanical Assembly ◽  
Mechanical Assemblies ◽  
Statistical Tolerance ◽  
The Individual ◽  
Statistical Tolerance Analysis

Tolerance analysis aims toward the verification impact of the individual tolerances on the assembly and functional requirements of a mechanism. The manufactured products have several types of contact and are inherent in imperfections, which often causes the failure of the assembly and its functioning. Tolerances are, therefore, allocated to each part of the mechanism in purpose to obtain an optimal quality of the final product. Three main issues are generally defined to realize the tolerance analysis of a mechanical assembly: the geometrical deviations modeling, the geometrical behavior modeling, and the tolerance analysis techniques. In this paper, a method is proposed to realize the tolerance analysis of an over-constrained mechanical assembly with form defects by considering the contacts nature (fixed, sliding, and floating contacts) in its geometrical behavior modeling. Different optimization methods are used to study the different contact types. The overall statistical tolerance analysis of the over-constrained mechanical assembly is carried out by determining the assembly and the functionality probabilities based on optimization techniques combined with a Monte Carlo simulation (MCS). An application to an over-constrained mechanical assembly is given at the end.

scholarly journals A static analogy for 2D tolerance analysis

2014 ◽  
Vol 34 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Antonio Armillotta
Keyword(s):  
Functional Equations ◽  
Nonlinear Problems ◽  
Tolerance Analysis ◽  
Static Problem ◽  
Alternative Methods ◽  
Force Analysis ◽  
Correct Treatment ◽  
Content Type ◽  
Mechanical Assemblies ◽  
Free Body

Purpose – This paper aims to present a method for the tolerance analysis of mechanical assemblies that is suitable to nonlinear problems where explicit functional equations are difficult or even impossible to write down. Such cases are usually modelled by linearised tolerance chains, whose coefficients (or sensitivities) are calculated from assembly data. Design/methodology/approach – The method is based on the free-body diagrams of force analysis, which are shown to be related to the sensitivities of linearised functional equations. Such an analogy allows the conversion of a tolerance chain into a corresponding static problem, which can be solved by common algebraic or graphical procedures. Findings – The static analogy leads to a correct treatment of tolerance chains, as the analysis of several examples has confirmed by comparison to alternative methods. Research limitations/implications – Currently, the method has only been tested on two-dimensional chains of linear dimensions for assemblies with nonredundant kinematic constraints among parts. Practical implications – The proposed method lends itself to ready application by using simple operations with minimal software assistance. This could make it complementary to current methods for calculating sensitivities, which are mathematically complex and require software implementation for deployment in industrial practice. Originality/value – Analogy with force analysis, which has not been previously highlighted in the literature, is a potentially interesting concept that could be extended to a wider range of tolerancing problems.

Generalized 3-D tolerance analysis of mechanical assemblies with small kinematic adjustments

1998 ◽  
Vol 30 (4) ◽  
pp. 367-377 ◽  
Author(s):  
JINSONG GAO ◽  
KENNETH W. CHASE ◽  
SPENCER P. MAGLEBY
Keyword(s):  
Tolerance Analysis ◽  
Mechanical Assemblies

A Comprehensive Tolerancing System for 3D Mechanical Assemblies

2010 ◽  
Vol 139-141 ◽  
pp. 1289-1293 ◽  
Author(s):  
Dong Ya Yang ◽  
Jun Gong
Keyword(s):  
Design Principle ◽  
Tolerance Analysis ◽  
Automatic Generation ◽  
Geometric Feature ◽  
Design Practice ◽  
Simulation Environment ◽  
Assembly Tolerance ◽  
Detail Design ◽  
Comprehensive Method ◽  
Mechanical Assemblies

A comprehensive tolerancing system is presented with its design principle, system architecture and key functions. The following functional modules, automatic generation of dimension chain, equivalent variational mechanism (EVM) modeling and visualized 3D tolerance analysis, are described in detail. Design intent is expressed by assembly tolerance specifications, which may be added to the model and used in computing predicted quality levels. A comprehensive method, based on equivalent replacement, has been developed for modeling variations in 3D mechanical assemblies. The models are constructed of common engineering elements: dimension chain, kinematic joints, assembly datums, dimensional and geometric feature tolerances, and assembly tolerance limits. The method is consistent with engineering design practice and is well suited for integration with commercial CAD systems. To make the tolerancing system robust and efficient, new functionalities are added to well-known CAD software and simulation environment. Tested by many samples, this system shows good robustness and practicability.

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