In this study, we investigated the free vibrations of a marine aluminum plate that
has a central crack and floats on water and evaluated the natural frequencies of the
plate. The method used on the governing equations is the Galerkin free element
method (EFG) and we used the moving least squares method (MLS) to obtain and
approximate the shape functions. Also, in order to simulate and apply the effect of
water on the plate, we used the simple method of adding mass. Rectangular plate
and simple support conditions are considered. First, validation was done for healthy
plate, plate in contact with water, and plate with cracks, and after ensuring the
accuracy of the method, we changed different parameters such as the size and angle
of the crack, plate thickness, and plate dimensions to determine the effect of each
on the plate natural frequency. evaluate. Finally, one of the results of the method
was the reduction of the natural frequency of the cracked plate in contact with water
compared to the healthy plate in vacuum.