Calculation Method for the Penetration Depth of Missile Impact on Nuclear Containment Concrete Walls Based on Plastic Limit Theory

The containment structure is the final barrier in nuclear power plants, designed to prevent the release of radioactive materials under severe accident conditions. Missile impact can pose a serious threat to the integrity of the containment concrete wall. This paper presents a new method for predicting the penetration depth (nonperforation) of missile impact on concrete walls based on the plastic limit theory. First, the penetration resistance of the missile when its nose partially and completely penetrates into the concrete wall is analyzed with consideration of the strain rate effect, and the corresponding equations of motion are established. Then, equations for predicting the penetration depth are derived for missiles with various nose shapes. Finally, the accuracy of the proposed method is validated against extensive test data. The results show that the proposed method can clearly reflect the penetration mechanism, and the predicted penetration depth is in good agreement with the test results. Utilizing the proposed method, the velocity-time and acceleration-time relationship of the missile during the penetration progress can be accurately established.