Abstract
This paper proposes a modeling method of stress concentrated members for the first order analysis (FOA). When a complicate solid structure is simplified as an assemblage of simple beam elements applied to element forces such as axial force, shear force, bending moment and twisting moment, the total stiffness equation for FOA of the solid structure is constructed and solved for the given boundary and loading conditions by the usual FEM manner. Then, the total deformation of simplified model is estimated and the element forces are calculated in the element level. The stress concentration of simplified each member with holes, notches and variable cross section is also predicted by the suggested approximate formulation. A U-notched 3D-model is picked up and how the suggested formulas can predict the stress concentration precisely will be shown. These formulas can be used to show the influence of the design parameter changes to the designer and how the load transmission path will change by the design changes.
