Vilensky O.Yu., Lapshin D.A., Novinsky E.G., Rusinov N.S.
Afrikantov Experimental Design Bureau for Mechanical Engineering, Nizhny Novgorod, Russia
The paper presents basic results of analysis of deformation process and estimation of pipe mockup falling on a reactor roof (RR).
Reactor protection against possible falling of various pieces of equipment is provided by keeping RR integrity and no unallowable deformation on it. Full-scale representative testing of RR under dynamic impacts is rather difficult because of a large cost.
To decrease costs, at the design stage representative analytical studies were performed, and the design was optimized considering the shock resistance requirements to mitigate consequences of troubles in operation in course of transportation and handling operations at the reactor plant.
Computation analysis of falling is performed using dynamics computation module LS-DYNA of program complex ANSYS certified by Rostekhnadzor. The LS-DYNA module is intended for computation analysis of high-linear dynamic processes by an explicit scheme of integration of dynamics equations.
Mathematical analysis was made using a verified model of the behavior of a structural material used in the reactor roof, which was built based on the results of experimental studies under compression and tension conditions at various deformation rates and temperatures.
The obtained results permitted to analyze collision process, determine values of plastic deformations occurred in reactor roof elements.
Application of an integrated approach implemented in this computation analysis permitted to solve, with a moderate percentage of conservatism, a problem associated with safe reactor plant operation.
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