LICENSE: if you use this code it is mandatory for you to cite the paper below:

Implementation of Finite Element Method in Matlab for assessing modes and natural frequencies of 2D rectangular plates Augusto Carvalho de Sousa and Jeferson Rafael Bueno

Proc. Mtgs. Acoust. 30, 025005 (2017); https://doi.org/10.1121/2.0000779

This paper presents results for the assessing of the first six natural frequencies and modal shapes of a 2D rectangular plate with dimensions 200 mm × 500 mm × 2 mm, supposedly a door, with motion restrictions in certain points, supposedly the door ringes and handle. The assessment was made via a self-taught algorithm in MATLAB and the results were compared to COMSOL simulations. The mesh, mass and stiffness matrices, as well as their assembling, is taught through the document. Symbolic language was used to enhance the learning process. A maximum error of 6.02% was found between the two approaches for the 3rd natural frequency. Future research with this approach includes the coupling between the plate and an air cavity and the assessing of the modal shapes and natural frequencies of this system.