CAD-FEA study on parameter sensitivity in the Grodzinski method for an axial load case

Abstract

In mechanical design it is necessary to reduce the stress concentration in areas of the structure with sudden geometrical changes. Topology and shape optimization is a modern tendency, but it implies some theoretical and practical difficulties. As an alternative, there is so called “simplified shape optimization”, making use of several shapes, available within modern CAD editors (FILLET, ELLIPSE, etc.) or copying the forms of the bionic structures. The final decision depends on the performance of a specific shape in reducing the stress concentration but also its ability to be implemented in a particular arbitrary case. The paper presents the Grodzinski method, that can be used in stress concentration areas with practically any aspect ratio. There is hardly any reference in the literature on the influence of the <i style="mso-bidi-font-style:normal">n</i> parameter (the number of division intervals in geometrical construction). A CAD-FEA study is performed on the influence of increasing <i style="mso-bidi-font-style: normal">n</i> parameter. The test case is a notched specimen, axially loaded. There are analyzed stress concentration coefficients <i style="mso-bidi-font-style: normal">K</i>_t, <img src='http://www.niscair.res.in/jinfo/sigma1.gif' border=0>_vonMisses and some geometrical characteristics of the stress concentration area. The results of the Grodzinski profiles are compared with the alternative options FILLET and ELLIPSE.

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