NUMERICAL SIMULATION OF DYNAMIC DEFORMATION OF AIR TRANSPORT PACKAGE IN HIGH-SPEED ACCIDENTAL IMPACT

In accordance with IAEA regulations, a package for air transportation of radioactive materials (a Type C package) must meet certain strict requirements. One of these requirements is that the package must be strong enough to withstand an impact with a hard surface at any angle and at a speed of at least 90 meters per second (m/s). On the one hand experimental testing of resistance of air transportation packages is very expensive. Therefore, experimental tests with the real packages need to be carried out only after overall detailed computer simulations of dynamic behavior of the structure during impacts at different angles, which define the “weakest” elements of the structure and the most dangerous direction of impact. On the other hand it is necessary to involve any available experimental data for verification of results of numerical modeling because the problem is really complicated. Dynamic deformation of the structure under high-speed impact with the hard surface is an extremely non-linear process, which has several specific aspects as follows: • large displacements (huge changes of initial structure shape); • high levels of plastic strains; • multiple contact interactions between structures elements and hard target. Practical solution of this problem with acceptable accuracy could be obtained by using the finite element code LEGAK-DK developed at RFNC-VNIIEF. The brief description of the code LEGAK-DK and its application for analyzing the large deformations dynamic response of structures is presented in the paper. The results of numerical investigation of the Type C package accidental impact with the hard surface at a speed of 90 m/s are also presented. Comparison of the calculated deformed package shape with experimental data shows that they are in a good agreement.