Finite element analysis of perforated metal sheets

Abstract

Perforated sheet metals have a wide variety of applications in engineering such as auto parts, computers, aerospace technology and even architectural design. Due to the increasing need for lightweight and efficient structures, perforated sheet metals have become a popular alternative to conventional sheet metals.

In this project, the stresses, deflections, and vibration characteristics of perforated sheets are studied using FEA. ANSYS-Mechanical APDL (ANSYS 2021 R1 Student Version) is used for this purpose. 2D models of perforated sheets with varying number of holes are constructed using ANSYS preprocessor. The models are meshed with solid 183 elements and subjected to tensile loading. Using the computed tensile deformations, equivalent Young’s modulus and Poisson’s ratio are determined. The load carrying capacity (i.e., the maximum load the plate can carry before yield failure) is also determined for models with varying number of holes. As an attempt to verify the effectiveness of the equivalent Young’s modulus and Poisson’s ratio, plates without perforations are modelled with the equivalent Young’s modulus and Poisson’s ratio, and the displacements are computed and compared with that of the perforated models.

Free Vibration analysis is also conducted to determine the natural frequencies and mode shapes of the perforated metal sheets and a verification analysis is also carried out to study if a metal plate without perforations using the equivalent material properties yields natural frequencies similar to that of perforated models.

The effectiveness of the equivalent material properties is also tested on a more realistic problem involving axial as well as bending deformations.

Based on the investigations, the equivalent material properties are found to be accurate in axial loading conditions rather than coupled bending cum axial loading deformations.