Dynamic Design Analysis Method (DDAM) Response Spectrum Analysis with Abaqus

The Dynamic Design Analysis Method (DDAM) is a U.S. Navy methodology for qualifying shipboard equipment and supporting structures for survival of shock loading due to

underwater explosions (UNDEX). The DDAM is a regimented collection of procedures that utilize estimates of the peak linear dynamic response of ship equipment and structures

obtained from normal mode response spectrum analyses. The response spectra are usually based upon empirically obtained Shock Design Values (SDVs) that are dependent on the type of ship, mounting location, direction of attack, response frequencies, and overall survivability

requirements. The requirements for efficiently implementing the DDAM procedures are quite extensive. However, the customization capabilities with Abaqus/CAE are ideally suited for

streamlining the process. In this technology brief a custom GUI application, designated as DDAM for Abaqus, is presented. It is designed to capitalize on the excellent normal

mode capabilities within Abaqus and allows engineers to perform DDAM analyses efficiently. DDAM for Abaqus is available with the release of Abaqus Version 6.5-3 and is free and unlicensed for existing Abaqus sites.