Seismic response of electrical cabinets considering primary-secondary structure interaction with contact nonlinearity of anchors

Seismic assessment of safety-related equipment in a Nuclear Power Plant (NPP) is more demanding compared to general structures owing to their role in the safe operation and shutdown of the plant. In-cabinet response spectra (ICRS) is thereby generated to qualify the performance of the sensitive devices installed in a cabinet. This study presents the effect of post-installed anchor interaction on the seismic response of an electrical cabinet to drive the ICRS considering primary-secondary interaction (PSSI). Nonlinear hysteretic shear behavior of the anchor connection and its interaction with the floor was considered. An equivalent numerical model was developed to imitate the nonlinear behavior of the anchor bolt. The numerical behavior of anchor was validated using the recent available experimental results. A parametric study for the coupled and uncoupled condition was also considered. The seismic response manifests the nonlinear interaction of anchor bolt that is significant to be considered. The response amplification in a coupled system with anchors nonlinearity is more significant than the floor response spectra (FRS) method and the fixed boundary condition. Moreover, for tuned and nearly tuned primary-secondary systems under the linear and nonlinear connection is also addressed.