Dynamic Response Experiment And Simulation Analysis Of Polar Crane Of Nuclear Power Plant Under Earthquake

Taking the polar crane of nuclear power plant as the research object,the dynamic seismic behavior of the polar crane under different working conditions and different seismic excitations is studied through shaking table experiments and numerical simulations,which provides basic data for improving the seismic performance of the polar crane.Based on the similarity theory,a similarity criterion for dynamic response of the polar crane under earthquake is proposed,and the similar relationship between the polar crane prototype and the experimental model is determined.Using finite element numerical simulation methods,the dynamic responses of the polar crane prototype and the 1:16 scale model under the El Centro seismic wave are simulated.By comparing the dynamic response of the polar crane prototype and the 1:16 scale model with the finite element simulation,the correctness of the derived similarity theory is verified numerically,which provides a theoretical basis for the next seismic analysis of the polar crane.After comprehensively considering the main purpose of the experiment,the characteristics of the prototype structure and objective experimental conditions of the polar crane,a 1:16 polar crane scale experimental model is designed and processed.According to the main experimental purposes,the shaking table experiment is designed and completed.The experimental data such as natural frequency,acceleration,strain,and wheel pressure are measured.Then the experimental data are calibrated and analyzed.The dynamic response of the polar crane experimental model under different conditions and different earthquake excitations is obtained.The experimental results show that the seismic intensity has a great influence on the acceleration of the polar crane.When the seismic intensity increases by 66%,the vertical acceleration response of the small car of the polar crane model is amplified by 3.27 times.The vertical acceleration response of the bridge is amplified by 2.45 times,and the horizontal acceleration of the bridge is magnified by 0.995 times.The lifting height has little effect on the acceleration of the structure and the deformation of the bridge,when the lifting height is in the middle,the response of the experimental model in the vertical direction is less than the other two positions.According to the polar crane experiment model,the corresponding finite element model was established using ANSYS.The modal analysis and time history analysis are performed.And the vibration modes,accelerations and stresses are statistically compared.The comparison results show that the first-order natural frequencies of the experiment and the simulation are close to each other,the deviation is 2.96%;the deviation of most measurement points in the experiment and simulation is 10%,and the deviation of most measurement points in the experiment and simulation is 25%.The results are in good agreement and the correctness of the numerical simulation is verified.