The effect of using shell and solid models in structural stress analysis

Abstract

Computer aided engineering analysis is commonly used to evaluate and improve the performance and reliability of the products in today’s manufacturing industry. Computer aided engineering analysis software use finite elements method in their solutions. The most significant problem in practicing these analyses is to form the mesh structure properly. The aim of this study is to research the effects of using surface and three-dimensional solid models in structural stress analysis. In this context, the maximum deformation in a square beam subjected to bending was calculated analytically and numerically. The solid model and surface model were created via CATIA. These models were analyzed under the same conditions in the static analysis module via ANSYS workbench. A difference of 1.32 % was detected between the numerical solution and the numerical displacement value of the surface model, and a difference of 11.84 % was detected between the numerical solution and the displacement value of the solid model. The difference between the von mises stress values of both models is approximately 30 %. In the parametric assessment conducted regarding the change in the mesh size, it was discovered that the results were affected by the mesh size significantly, and the mesh size and stress increased by 1550 % with the singularity problem in the solid model. In systems subjected to bending, using a shell mesh with 6 degrees of freedom is more advantageous in terms of solution time, operational capacity, stability and accuracy of the result.