Study of natural frequencies of a welded industrial fan impeller using the APM FEM software package

Purpose of the study is to obtain numerical values for the occurrence of resonance of the studied structure and to evaluate the influence of the number of welds on the resonance of the impeller of an industrial fan in the APM FEM software package. Methods. This article uses the finite element method (FEM) analysis of a welded industrial fan impeller structure using the APM FEM software package for KOMPAS-3D v23.0.0.8. The structure was modeled using KOMPAS V23, and the welds were modeled using the "Permanent Joints" application in accordance with GOST 14771–76-T3. Weldto-solid conversion was applied to the weld locations to account for them when generating the finite element mesh. Results. Based on the analysis, it can be concluded that the design has a high vibration resistance margin under nominal loads. Increasing the number of welds from two to four per blade of the industrial fan impeller during design slightly increases the resonance risk. Therefore, the design can be recommended for manufacturing with a minimum number of welds, namely two per blade. Conclusion. An analysis of the welded structure of an industrial fan impeller using the APM FEM software package showed that when examined for the presence of natural frequencies, the structure retains its strength and geometric stability, and the obtained numerical values of resonance occurrence significantly exceed the values possible during operation. For the variant with two welds per blade, the natural frequencies of the first five modes were 357.42; 363.01; 363.36; 365.73 and 367.13 Hz. For the variant with four welds, the corresponding frequencies were 383.33; 391.77; 394.39; 396.63 and 397.18 Hz. The obtained numerical values of the expected occurrence of resonance comply with the requirements of regulatory documents.