Structural Dynamics

Structural Dynamics

In a Rigid Dynamics analysis, when I overwrite the mass property of a body using the SetMassAndInertia() command, my result seems to be scaled up by 1000. For instance, I use the following: _myblockID = CS_Body.Find(_bid) _myblockID.SetMassAndInertia(10,0,0,0,0,0,0) I’m assuming that the solver will read in 10 kg for the mass. Performing a simple test involving gravitational acceleration, the force is 1000 times greater than what is expected. I am in mm,kg,s unit system.

    • FAQFAQ
      Participant

      If the active unit system is set to mm,kg,s, then the solver unit system will measure the mass in metric tons. Since 1 ton equals 1000 kg, the result will be scaled by 1000 if the appropriate conversion is not done beforehand. Keep in mind that command objects do not automatically scale quantities; they are units agnostic and take numerical inputs of both integers and floats. The usage of the solver unit system is not apparent because the solver output makes no indication of this, so we plan to enhance the command object header to reference the units used for the solver unit system.