Abstract: The six order natural frequencies are extracted from amplitude-frequency curve and modal shapes are tested through the experimental modal analysis carried out by the 1:10 scale similar test model and the prototype of 27 m2 large-scale linear vibrating screen. According to the similarity theory the relative error of the natural frequencies between the prototype of vibrating screen and the similar test model is less than 8.62%. The modal shapes of all orders are consistent between the prototype of vibrating screen and the similar test model. The results show that the inherent parameters of the linear vibrating screen can be obtained visually and effectively by using modal analysis method, which provides theoretical foundation for improving service life, reliability and structural optimization of the linear vibrating screen. The modal experimental results of the 1:10 scale similar test model are proved to be correct and valid compared with the data of the prototype of vibrating screen and the consistency and reliability of the experimental data are verified. The experimental modal analysis can be carried out by the similar test model instead of the prototype of the large-scale linear vibrating screen approximately, which provides reference for similar experimental studies.

Key words: Modal analysis, Similarity, Test model, Vibrating screen