### Abstract

In a wide range of the Reynolds number an elastically suspended
circular cylinder surrounded by a homogeneous wind velocity field
will generate vortex shedding of a frequency that by and large is
proportional to the far field wind velocity. However, if the
cylinder is free to vibrate, resonance will occur when the vortex
shedding frequency equals an eigenfrequency of the cylinder. This
vibration causes a feedback to the velocity field such that the
vortex shedding frequency becomes "locked in" at the considered
eigenfrequency within a rather wide interval of the wind velocity
(Sarpkaya 1979). Recent wind tunnel experiments show that the
position and width of the interval depends on whether the wind
velocity increases or decreases. Also the experiments show that
the presence of even a low degree of turbulence in the wind causes
the interval bounds to be rather uncertain. For the degree of
turbulence observed in the natural wind the undisturbed local wind
velocity directly upstream to the cylinder varies as a sample from
a random process. Thus the local wind velocity will cross in and
out of the "iock in"-intervals in a random fashion causing pulse
like bursts of strong vibrations. The paper describes a random
pulse process model of this vibration behavior supported on the
experimental work of the first author. Moreover, it is shown how
the mean accumulated material fatigue damage per time unit
according to the Palmgren-Miner rule can be evaluated by
simulation.

Original language | English |
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Title of host publication | Stochastic Structural Dynamics |

Place of Publication | Mayaguez, Puerto Rico |

Publisher | University of Puerto Rico |

Publication date | 1997 |

Publication status | Published - 1997 |

Event | Third International Conference on Stochastic Structural
Dynamics - San Juan, Puerto Rico Duration: 1 Jan 1995 → … |

### Conference

Conference | Third International Conference on Stochastic Structural Dynamics |
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City | San Juan, Puerto Rico |

Period | 01/01/1995 → … |

## Cite this

Christensen, C. F., & Ditlevsen, O. D. (1997). Fatigue damage from random vibration pulse process of tubular
structural elements subject to wind. In

*Stochastic Structural Dynamics*University of Puerto Rico.