Traditional TPA Process (two-step TPA)

Step 1: Calculate attachment Forces of the system in an assembled state:

1. Assemble the system together and identify responses for which TPA analysis will be performed.
2. Calculate forces acting on the attachment DoFs, as well as the responses for comparison with TPA calculated ones.
3. Identify all attachment points through which load maybe transferred from the excited structure (Powertrain and Chassis in the picture above) to the responding structure (the Body). Each Degree of Freedom (DoF) at the attachment points becomes a transfer path.

Step 2: Calculate Transfer Functions (TF) of the responding structure in an isolated state:

4. Break the system at the attachment points, and perform Free Body analysis with the responding structure isolated, as if it is not connected to the excited structure.
5. Calculate the cross transfer functions (Tactile Transfer and Acoustic Transfer in the picture) between the attachment points to the response points, as well as the driving point transfer functions (Point Mobility in the picture), by applying a unit load to each attachment DoF.

   
   
   Figure 1.