Non-destructive buckling load estimation of oblate ellipsoidal domes using the vibration correlation technique

In this paper, experimental and numerical studies based on the vibration correlation technique (VCT) are employed to non-destructively determine the buckling load of oblate ellipsoidal domes subjected to external pressure loading. Two nominally identical isotropic oblate ellipsoidal domes are fabricated, and experiments are conducted using specially designed fixtures and a hydraulic system for applying pressure. The dome’s deformation, strains, and modal response are measured at different pressure loads and analyzed. Conventional and modified VCT approaches are used to evaluate the buckling load. The experimental buckling results are compared with VCT predictions and the effect of various factors like mode number of interest, reference natural frequency, number of data points, and reference critical buckling load are studied. The results from this work serve as a validation for the applicability of VCT in predicting the buckling load of oblate ellipsoidal dome structures.