# Combined method of identification of free oscillations of perforated riffled plates

## TL;DR

This paper presents a combined experimental and numerical method to predict the natural oscillation frequencies of perforated plates with riffles, helping assess their durability and deformation risks.

## Contribution

A novel experimental–numerical approach for analyzing the oscillation frequency of riffled perforated plates with validated models and derived equations.

## Key findings

- Natural oscillation frequency depends on plate thickness, riffle height, and pitch arrangement.
- The method enables prediction of crack formation between holes in riffled perforated plates.
- Equations describing the frequency dependence on key parameters were derived and validated.

## Abstract

Presented experimental–numerical method of prediction of modal characteristics of rectangular perforated plates with riffles. The technique allows to analyze the oscillation frequency of plates with holes and stamped riffles. The methodology is based on numerical modeling by FE-methods and experiments to obtain the regularities of changes in the natural oscillation frequency of plate. The methodology involves numerical modelling in Abaqus, the adequacy of which is experimentally verified on a vibrometer PSV-500. Experimental studies are conducted on basic plates with elongated holes measuring 3.2 × 20 mm and 5 × 20 mm, as well as riffled plates with similar holes and different riffles. As a result of the research, dependences of the natural oscillation frequency of riffled perforated plates on their parameters are obtained in comparison with unriffled surfaces. The analysis of the obtained models is carried out and the levels of influence of significant parameters of riffled plates on their natural frequency are determined. The dependences of the natural oscillation frequency of plates on the plate thickness, height, pitch and riffles arrangement, as well as the equations describing them are obtained. The greatest influence on the natural frequencies of riffled perforated plates is exerted by: the plate thickness, the pitch arrangement and the riffle’s height. The obtained regularities of the natural oscillation frequencies of riffled perforated plates may allow for predicting the appearance of deformations in the form of cracks between the holes and determining their durability

The online version contains supplementary material available at 10.1038/s41598-025-06614-5.