For each specified frequency, the ACS SASSI FORCE module forms the elements of the load vector which correspond to external forces such as impact and rotating machinery acting directly on the structure. The results are stored in File9.

The following options allow you to specify the analysis options for ACS SASSI FORCE module:

• Operation Mode - Select the operation mode from Solution and Data Check.
• Acceleration of Gravity - Type the acceleration of gravity. The value is the same as set in the Analysis Options - SITE dialog box.
• Frequency Step - Type the frequency step (Hz). The value is the same as set in the Analysis Options - SITE dialog box.
• Time Step of Control Motion - Type the time step of control motion (sec). The value is the same as set in the Analysis Options - SITE dialog box.
• Nr. of Fourier Components - Type the number of values to be used in the Fourier transform. The value is the same as set in the Analysis Options - SITE dialog box.
• Frequency Set Number - Type the number of the frequency set. The value is the same as set in the Analysis Options - SITE dialog box.

All forces and moments defined within the ACS SASSI PREP pre-processor (see F, MM, FREAD, MREAD) will be written to the input file for the ACS SASSI FORCE module.

Dynamic loads with similar time history but different maximum amplitude and arrival time may be applied at nodal points. Reference time history is defined as having maximum reference amplitude and zero arrival time (t₀), which means the load starts acting on the nodal point at time zero. All other time histories must be given relative to reference time history by defining load factor and arrival time. The load factor is defined as the ratio between the maximum amplitude of the applied load and the maximum reference amplitude, F_max / R_max.