Abstract: The modal analysis of four towers (Example 1st to 4th) in "NB/T 47041 standard interpretation and calculation example" is carried out with the finite element software ANSYS. The results show that the error between the numerical solution of ANSYS and the methods in standard NB/T 47041 is very small for the towers with no change or little change in section characteristics (Example 1, 3 and 4). And for the towers with big change in section characteristics (Example 2), the accuracy of the lumped mass method and matrix iteration method is subject to the number of sections and the numerical solution is more accurate.

Key words: ANSYS, towers, natural vibration period, mode shape function