Effect of Micro-holes Addition on the Natural Frequency and Mode Shape of Perforated Plates

Abstract

In this paper, an extensive work on the natural frequency of perforated plate has been made by introducing micro-holes on the plate. The micro-holes, which is known to have a remarkable performance in several applications, were arranged diagonally among the perforated holes in order to make a new combination of micro-macro perforated plate. A 3D geometrical model of the plate was made in the Autodesk Inventor and the Finite Element (FE) simulation was employed to calculate the natural frequency and visualize the mode shape. Four models were made with various micro-holes diameter starting from 0,25, 0,5, 0,75 and 0,9 mm, respectively. The macro holes diameter, however, was kept constant to be 1,5 mm purposely to know the effect of micro holes in particular. The results from the models were then compared to a single perforated plate (PP) for clarification. It is found that the micro holes gives considerable effect to the perforated plate natural frequency. Similar to the author previous findings, the diameter of the micro holes is proportional to the natural frequency reduction.