Impact load for tornado-generated missiles

Nuclear power plant structures are designed to resist impact loads from tornado-generated missiles. The paper gives a method to determine the contact pressure at the interface of the missile and the target, and the velocity and deceleration time-histories of the missile. It also gives a method to obtain the design load due to impact by tornado-generated missiles. The calculated design load compares very well with the total support reaction from a full-scale dynamic test. The comparison between the predicted deceleration and the deceleration recorded in a test is excellent. The method of determining the deceleration has also been used with very good results for earth-penetrating missiles.