Prescribed Nodal "Dead" Loads
Dead loads are forces that are directly prescribed at the nodes of the mesh. The amplitude and direction of such forces is known a priori. In particular it is independent from the deformation of the underlying material. Such forces also strongly depend on the chosen mesh desnity. Changing the mesh usually requires a complete redefinition of these forces.
As a consequence, it is usually a bad idea to define nodal “dead” loads in a model. To model realistic loads (pressure and shear) which depend on the deformed configuration and do not depend on the mesh density, use Pressure and shear.
Anyway, the command used for the definition of “dead loads is the same as Prescribed Displacements except that Field1D refers to a force instead of a displacement.