2.3.12. Automatic Mode Pairing Algorithm

This algorithm provides an indication of possible mode pairs between File 1 and File 2 modes. This algorithm is triggered:

  • By pressing the Pair Modes button in the MAC Frequency Worksheet. In this case the algorithm is automatically triggered.

  • By setting the Pair Modes property in the project Details to Yes. In this case the algorithm is triggered after the MAC Calculator is generated.

The algorithm employs the following nomenclature:

  •   set of modes of File 1.

  •   set of modes of File 2.

  •   Rigid Body Modes Cutoff Frequency.

  •   Absolute Frequency Tolerance.

  •   Relative Frequency Tolerance.

  •   MAC value between modes   and   .

  •   MAC Limit threshold.

The algorithm is outlined as:

  • All modes in both   and   sets below   are unchecked (eliminated).

  • All   of the surviving modes are ordered in descending order.

  • All   are not considered for mode pairing.

  • All the surviving   values are compared (starting from the highest to the lowest), and two frequency checks are performed:

    • Relative frequency check:   .

    • Absolute frequency check:   .

    If either the relative or the absolute checks passes, modes   and   are considered to be paired, and both of them are blocked to be paired with the subsequent modes.

The four parameters of the algorithm,  ,  ,   and   can be modified through their respective properties under the Details view.