02-14-2011, 07:46 PM
Hi. The mass must be assigned following the Benny explanation. Be carefull about the mass definition, because the DEAD LOAD (selfweight) mass assignation is taking duplicate the correct value. Use the option 2 to define the mass asignation, and use the DEAD LOAD value as 1 (selfweight load only), the other dead load cases (for example, OVERLOAD) with 1 also, the LIVE LOAD as %(0.25, 0.5 or the using code value) and the any additional vertical load cases participating in the dynamic analysis. Best regards.