32 B. Moldenhauer et al. Fig. 3.11 Analytical subsystem test vs FEM—(Top) natural frequency, and (Bottom) MAC plot The comparison for the half cube with the beam, or the analytical subsystem, is shown in Fig. 3.11. As with the TS, the FEM for the analytical subsystem agrees well in frequency and modeshape within the first ∼5000Hz. 3.6 Substructuring Prediction With the necessary modal data collected for each subsystem, the TSM may be applied as given in Eqs. (3.1) and (3.2). It is of note that, to define the constraint equations, a suitable basis of linearly independent TS FEM modeshapes must be chosen. If linearly dependent shapes are included, the pseudo-inverse in Eq. (3.2) becomes ill conditioned and an insufficient number of constraints are enforced to satisfy the coupling equations of motion, resulting in wildly inaccurate predictions for the
RkJQdWJsaXNoZXIy MTMzNzEzMQ==