In ansys always we use gravity load for static analysis as a default to capture self-weight of the frame same approach we have to use in NX simulation?
Solution
Gravity
In the Nastran environment, the options in the Gravity dialog box correspond to the fields on the GRAV bulk data entry. For Nastran models, you can use the Gravity dialog box to define the direction and magnitude of a gravity vector in any coordinate system you specify.
When you solve your model, Nastran multiplies components of the gravity vector by the mass matrix to obtain the components of the gravity force at each node. Since Nastran uses the mass matrix to compute the forces, you must have mass defined in the model, usually in the material assigned to the mesh.
Notes