Detaillierte Ermüdungsuntersuchungen für rechnerische Nachweise über die Normung hinaus am Beispiel von Glockenturmschwingungen

Detailed fatigue investigations for calculational proofs beyond standardization using the example of bell tower vibrations.

When building constructions are subject to dynamic loads the safety against fatigue failure has to be proven. In case of different dynamic loads simplified approaches often lead to very conservative results. Therefore existing capacity reserves can be used by more detailed considerations.
A method for such more detailed considerations of different dynamic loads is presented in this article using the example of a steel tower that is excited by the ringing of several bells.
For bell towers DIN 4178 gives orientation values for vibration velocities. If these values are not exceeded the vibrations are noncritical. If the orientation values are exceeded a range of measures to reduce the vibrations come into consideration. Alternatively there is the option to prove by further calculations that the existing vibration velocities even above the orientation values are harmless, e.g. by a fatigue proof.
In doing so the fatigue proof can be carried out with a simplified or a more detailed approach of the different dynamic loads. For both the simplified and the more detailed fatigue proof the method to determine the decisive loads and especially the decisive number of load cycles for the fatigue proof is explained using the case study of the steel tower.
It becomes apparent how unnecessary rehabilitation measures can be avoided by an increased effort of thinking and proving to capture the dynamic loads more precisely.