Hi,
 

I am using Abaqus CAE 2025 Standard/Explicit with Static, General step with python and would like to:
 

• apply inertial acceleration and an inertial angular acceleration to a specific set in my abaqus model
• the set contains an instance (with shell elements) and some point masses rigidly connected to the instance
• this is to replace the inertia relief formulation to allow computing two differently moving bodies (inertia relief will treat them as one body if I understand correctly)

However, I see the following issues

• Gravity loads and RotationalBodyForces cannot be applied to reference points apparently 
• as far as I am aware, the only way to create a point mass with python is with a reference point and engineeringFeatures.PointMassInertia. Hence, I cannot apply Gravity and RotationalBodyForce to my set that contains an instance and some point masses
   

My questions therefore are:

• a) why can a Gravity (but not RotationalBodyForce) then be applied to the whole model which includes my point masses, but not to my set that includes my point masses?
• b) is there a way to apply Gravity loads and RotationalBodyForces to a set that includes PointMassInertia objects? Or do I need to manually compute the respective rigid body accelerations of the PointMassInertia objects from their mass, inertia and distance from center of rotation?
   

Any thoughts are appreciated :)