The Virtual Fields Method applied to sandwich structures to obtain flexural modulus by modal analysis

The mechanical characterisation of panels by non-destructive testing allows to reduce costs and obtain additional structural information. Nearly three decades ago, Grédiac & Paris developed a non-iterative method for calculating the elastic properties of thin anisotropic composite plates under bending, called the Virtual Fields Method (VFM), using modal analysis under free-edge conditions. Despite being a classic method, there is still potential exploration for VFM, such as its application in sandwich structures, since there is no reference to the method applied to this material architecture. This work verifies the functionality of VFM by measuring the flexural modulus by modal analysis of a sandwich structure, statistically comparing the value obtained with data reported in the literature. The VFM proved to be statistically accurate.  Fundings: CAPES MSc Scholarship (SAC #1773569 & SCBA #88882.427173/2019-01) and CNPq (PQ1). Also on ResearchGate: http://bit.ly/3Py72sE.