Smallwood proposed control algorithms for MDOF random vibration as far back as the late 1970s, MDOF vibration was not formally recognized in the MIL-STD-810 until the 2008 release of MIL-STD-810G.
While modern MDOF excitation systems generally are designed to be multipurpose as discussed above, they are still found in various sizes ranging from table sizes of under 100 square inches with frequency response on the order of 5 khz to large earthquake systems capable of imparting motion on entire building assemblies with a frequency response generally below 100 hz.
Development of MDOF specific reference criteria and the inclusion of the MDOF criteria in military specifications are essential to the accuracy of an MDOF vibration test.
MDOF excitation and control systems continue improving and are standard equipment in many vibration test facilities.
The commercial analysis program SAP2000 was used to perform the Time-History Analysis (THA) of the MDOF system subject to all 14 records.
Since the Time-History records used to analyze an MDOF system are scaled to match the design response spectrum, a Single-Degree-Of-Freedom (SDOF) can be used for preliminary analysis [?
THA was performed using SAP2000 for three MDOF systems representing a typical seismic-isolated structure with a natural period of vibration equal to 2.