考虑表面形貌与受力变形的装配精度分析方法

Improving accuracy is one of the permanently pursued goals of the mechanical manufacturing discipline. With the continuous pursuit of higher precision for precision eletromechanical products, the accuracy requirements of tolerance analysis are also continuously improved. Hence, a method for assembly accuracy analysis with consideration of form defects and surface deformations is proposed. First, the positioning/orientation errors and form error are modeled by a small displacement torsor model and a linear basis function superposition method, respectively, based on the skin model shapes. Then, the contact deformations of different types of non-ideal matching surfaces are calculated by applying a conjugate gradient-fast Fourier transform algorithm. Thereafter, a modified polytope model is used to calculate the cumulative assembly deviations to achieve assembly accuracy analysis with a combined consideration of form defects and surface deformations. Finally, the differences of the instances considering the form defects and surface deformations whether or not are compared. The numerical results indicate that the proposed method can improve the accuracy of assembly accuracy analysis and provide more accurate guidance for product tolerance design.