Experimental Modal Analysis and Operational Deflection Shape Analysis of a Cantilever Plate in a Wind Tunnel with Finite Element Model Verification

Experimental methods are used across all engineering domains to study a system’s response to some specified input or forcing function. This work explores the response of a structural member in a wind tunnel containing a cantilever plate attached to a cylinder, under an impact excitation. The computer-aided design (CAD) model and finite element analysis (FEA) modal simulation of the experimental setup are introduced. Two experimental techniques used in this research are discussed – an accelerometer-based experimental modal analysis (EMA) method and a non-contact, full-field digital image correlation (DIC) operational deflection shape (ODS) analysis method. The FEA and experimental results of the first five mode shapes and natural frequencies of the cantilever plate are presented and compared. The modal assurance criterion (MAC) between FEA-based mode shapes and EMA-based mode shapes is at least 0.935 for each mode. Absolute values of percent errors between EMA-based and FEA-based natural frequency results are less than 5% for each mode, while absolute values of percent errors between ODS analysis and FEA-based natural frequency results are less than 11% for each natural frequency. When comparing the EMA method with the ODS analysis method, there is less than 2% difference between each mode’s natural frequency.