Seismic Non-linear analysis of Polar Crane
SMiRT-19, Toronto, Canada, August 12-17, 2007, Paper N K11-4
One of the requirements for Safe Design of NPP is that structures, systems, and components important to safety shall be appropriately protected against dynamic effects, including the effects of missiles, that may result from equipment failures. Consideration of such hazard is essential especially during seismic event for Polar Crane.
For seismic analysis a comprehensive finite element model of Polar Crane was developed. Model takes into account specific peculiarities of Crane design and dynamic characteristics of supporting structure. The following Crane's main parts were included in the model: Crane itself, special elements for seismic protection (shock absorber devices ) and
supporting concrete ring.
Seismic excitation in the form of Time History Acceleration was applied in the base of the supporting ring. A special investigation for Crane dynamic response was made with taking into account an angular seismic components. It was shown that crane's response parameters in this case could be amplified by 5 – 15 %.
Analysis of Crane motion has shown that correct accounting of slippage between wheel and rail could reduce seismic loads 4 – 6 times.
An other significant issue of performed analysis was dedicated to the different positions of the Crane during seismic event. On the base of variable calculations the most severe case was identified and analyzed.