Experimental Estimation of Buckling Load for Unstiffened Cylindrical Shell through Vibration Correlation Technique Utilizing Adjusted FEA

A cylindrical structure with geometric initial imperfections is vulnerable to buckling under compressive loads. In order to assess buckling loads without additional structural damage, the Vibration Correlation Technique (VCT) utilizes the relationship between compressive loads and natural frequencies. However, employing VCT, it is necessary to apply high compressive loads similar to actual buckling loads on the structure. This paper, compression and vibration tests on unstiffened metallic cylindrical shell structures were conducted, followed by modeling and finite element analysis (FEA). The material properties for FEA were adjusted using the compressive load-natural frequency equation. The buckling load was predicted through VCT by combining the natural frequencies obtained from the tests in the low compressive load range and the adjusted FEA results in the high compressive load range. This improved method of predicting buckling load was validated by comparing it with the accuracy of traditional VCT buckling load predictions.