Dimensional Tolerance Analysis of Mechanical Assemblies with Symmetric and Asymmetric Tolerances

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.

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Tolerance Analysis of Mechanical Assemblies Using Monte Carlo Simulation—A Case Study

Lecture Notes on Multidisciplinary Industrial Engineering - Operations Management and Systems Engineering ◽

10.1007/978-981-13-6476-1_1 ◽

2019 ◽

pp. 1-15

Author(s):

Pradeep K. Singh ◽

Vaibhav Gulati

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Tolerance Analysis ◽

Mechanical Assemblies

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A static analogy for 2D tolerance analysis

Assembly Automation ◽

10.1108/aa-05-2013-050 ◽

2014 ◽

Vol 34 (2) ◽

pp. 182-191 ◽

Cited By ~ 10

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.

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