Dynamic responses of a steel-reinforced concrete target impacted by aircraft models

To investigate the characteristics of the impact load for a large commercial aircraft impacting upon a nuclear power plant, an integral test measurement system is developed through the experiments of aircraft models in middle sizes impacting upon a movable steel-reinforced concrete target via a rocket sled loading test platform. Three impact tests with different sizes of the aircraft models were carried out. In all the tests, the flying attitude and velocity of the aircraft models were recorded by a high-speed photography system. The acceleration and velocity time histories of the target were obtained by an acceleration measurement system and a DISAR system, respectively. The computed results of the impact loads calculated by using the measured acceleration and velocity data, respectively, are found to be in good agreement, which verified the reliability of the measurement system. Moreover, the acceleration time histories of the aircraft models were obtained by using the onboard overload storage, and, based on the measured data, the crushing load of the aircraft model can be calculated. On the other hand, the impact load time histories are also calculated by using the modified Riera equation, and the computed results are found to be consistent with that calculated by using the measured acceleration or velocity data of the target. In addition, the correction coefficient α in the modified Riera equation is also determined. Finally, an engineering calculation method and a formula to calculate the aircraft's impact load are proposed, with no need for knowing in advance the aircraft's crushing load distribution data. Moreover, the impact load of an aircraft calculated by using the engineering formula can be used in the evaluation on the impact resistance of the structure in a nuclear power plant, and the evaluation results will be impulse conservative.