It is crucial in fields that require high geometric precision and advanced technologies, such as aeronautics and automotive, to perform tolerance analysis for assemblies, particularly at an early design stage. This helps to limit the effect of assembly parts variabilities and facilitates the making of robust decisions. In the literature, few methods are presented for the tolerance analysis for compliant assembly. The Direct Monte Carlo (DMC) and the Method of Influence Coefficients (MIC) are widely used in such cases. MIC has proven advantages in terms of time and cost reduction. Nevertheless, the contact problem is generally not taking into account by this conventional method. When dealing with the non-rigid assembly of non-ideal parts, it is important to consider the contact between the components. This can provide more information about the real behavior of flexible assembly and lead to robust control of overall variations. The aim of this work is to address these issues and contribute to the prediction of flexible assembly variations of parts presenting geometric defects. The main objective of this paper is to contribute to the performance of tolerance analysis for non-rigid parts with shape errors by using the analytical Method of Dimensionality Reduction (MDR) instead of the traditional MIC method. This methodology provides a new model for predicting the flexible assembly variation of thin parts with analytical formulation. Indeed, it allows us to take into account shape defects and contact between parts which is the originality of this work. A case study is presented to illustrate and validate the proposed approach. The results lead to predict the variation of the assembly with respect to the geometric parts form. The new methodology offers several advantages over conventional MIC, the results of which are detailed and discussed in this paper.
