DDAM Analysis with LS-DYNA

DDAM (Dynamic Design Analysis Method) is a U.S. Navy-developed analytical procedure for shock design. It helps validate the design of onboard equipment and structures subject to dynamic loading caused by underwater explosions (UNDEX). It is a widely accepted procedure for safety evaluation for civil and military ship building. The keyword for response spectrum analysis (*FREQUENCY_DOMAIN_RESPONSE_SPECTRUM) in LS-DYNA has been extended to run DDAM analysis for shipboard components, with the option _DDAM. This paper first gives a brief review of the theory for DDAM analysis. Then, with several examples, this paper shows how to run DDAM analysis with LS-DYNA and how to perform post-processing of the results. For purpose of cross-validation, the results of DDAM analysis with LS-DYNA in the first example are compared with that given by other commercial code.