Minimização da concentração de tensão em componentes mecânicos via otimização estrutural

Abstract

This work has as objective to present an approach to minimize stress concentrators in mechanical components using ANSYS®. The objective is to develop solutions that can help reduce maximum stress levels in stress concentration in mechanical components. Stress concentration minimization is an important challenge in engineering because these points are common in many mechanical components, such as welded joints, holes, notches, and chamfers. These stress concentrators can significantly reduce the mechanical strength of the component, resulting in premature failure. Therefore, it is essential to develop method to minimize these stress concentrators, increasing the component's useful life and reducing maintenance and repair costs. To achieve this objective, three engineering problems were developed, each with its own objective function and design variables. The first problem consisted of a symmetrical flat plate with a central hole and a stress reliever, in which the objective function was to reduce the stress concentrator by changing the design variables. Two optimization methods were tested, Nonlinear Programming by quadratic Lagrangion (NLPQL) and Adaptive Single-Objective, and the latter was chosen for the other two problems as it is independent of the initial condition to find the global optimum of the objective function. The second problem consisted of a threaded bar, with the objective of reducing stress concentration by altering the notch. In this case, there was a significant reduction in stress concentration. The third problem was an asymmetrically perforated beam, with the objective of reducing the maximum von Mises stress, where increasing the design variable was less significant than problem 2. The results obtained showed that the proposed approach can be effective in reducing stress concentrators in mechanical components and that the Adaptive Single-Objective method is an effective approach for optimizing mechanical components.