PSI - Issue 78

Laura Gioiella et al. / Procedia Structural Integrity 78 (2026) 1436–1442

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Fig. 3. Comparison of the roof lateral displacement derived from the roof camera (T0) and the ground camera (T7).

The longitudinal and lateral platen displacements measured by the shake table controller (acquired at 512 Hz) and by the roof camera are compared in Fig. 4. Aside from resampling the controller data to match the camera acquisition rate (100 Hz) and aligning the signals, no additional processing was applied. Since the displacements from the roof camera are obtained as the difference between the positions of two targets (T0 and T1) located at nearly the same distance from the camera, the disturbances visible in the individual target signals—such as those shown for T0 in Fig. 3—are inherently compensated. This is confirmed by the close-up views in Fig. 4, which focus on the peak displacement intervals and show that the shake table motion captured by the roof camera is virtually free of noise, despite the intense disturbances induced by the high roof accelerations (on the order of 1 g or higher).

Fig. 4. Comparisons of the platen longitudinal and lateral displacements measured by the shake table controller and by the cameras.