International Journal of Civil & Structural Engineering
Author(s) : AISSA MOHAMMED HEMZA , AMAR BOUZID DJILLALI
Many countries are now planning to build new wind farms with high capacity up to 5MW. Consequently, the size of the foundation increased. This kind of structures are subjected to fatigue damage from environmental loading mainly due to wind and waves as well as from cyclic loading imposed through the rotational frequency (1P) through mass and aerodynamic imbalances and from the blade passing frequency (3P) of the wind turbine which makes their behavior dynamically very sensitive.That is why natural frequency must be determined with accuracy in order to avoid the resonance of the system.