Abstract: The natural vibration cycles of coupled in-line towers, especially its first three model vibration cycles, are the important in dynamic analysis. In this paper the authors discuss emphatically the bonding vibration along the longitudinal direction of coupled in-line towers. Using the supporting and connecting conditions of the towers, the differential vibration equations are obtained and reduced to a matrix equation. With the determinant of the matrix of coefficients of this equation set to zero, the natural vibration cycles of coupled in-line towers can be obtained rapidly by IBM-PC microcomputer. The results are in good agreement with the experimental data measured in the field.

Key words: 排塔, 自振频率, 自振周期, finite element simulation, numerical simulation, surface morphology, thermal contact resistance