Experimental Verification of Dynamic Stress Analysis Performed With DYNA 3D

Full scale drop tests of casks to be licensed as type B(U)- packages according to the IAEA- Regulations are in most cases necessary because certain specific cask features (i.e. bolts, welds) are not easi ly modeled. However, larger shipping casks can weigh up to 100 tons or more. The tests are extremely expensive and only a limited number of test facilities exist. If it can be shown that computer methods give reliable results for simulated drop tests, the number of necessary tests can be reduced. Static and/or one- dimensional computer models in most cases do not give satisfying results. Since the 3-dimensional dynamic finite element code DYNA 3D (developed by LLNL) was made available to us, we were interested in showing the possibilities of this powerful tool by comparison of measured test results with computed stresses in the cask body. For this purpose a series of carefully instrumented drop tests with ductile cast iron casks were chosen.