In the input specification to the RIFLEX module INPMOD the user is allowed to select mass and force units. This is done by specifying the gravitational constant as the ratio of force to mass units. In order to allow inconsistent units, e.g. \(\mathrm {kN}\), \(\mathrm {kg}\), \(\mathrm {m}\), \(\mathrm {s}\), the acceleration in terms of force to mass will be different than acceleration in terms of the ratio length to squared time. A constant is therefore introduced as a specification of the difference, see the RIFLEX User Guide for further details.

The unit specification made by the user in INPMOD also applies to the results from the VIVANA module.