Simple calculation method for stress concentration and stress intensity of T-shaped member

• The influence of shape parameters on stress concentration was shown in simple forms.
• The relation between shape parameters and stress concentration is analyzed by FEM.
• A method of approximating the stress concentration in an actual shape is proposed.
• The proposed method was validated with existing analytical solutions.

The objective of this study is to clarify the influence of shape parameters on the stress concentration in simple forms. In recent years, by the spread of general purpose Finite Element Method (FEM) analysis software, anyone can carry out FEM analysis now and can grasp the stress state of a structure. However, in order to grasp the influence on a stress state when some shape parameter has changed, FEM analyses for each shape are required, and it requires long time. As an example of this issue in fatigue strength design, the relation between the plate and rib in a T-shaped structure, containing a corner, is analyzed. The stress concentration factor or stress intensity factor between these two connected shapes are analyzed by the FEM, and a method of approximating the stress concentration factor and stress intensity factor in an actual shape is proposed. Then, the proposed FEM-based method was validated through a comparison of the results obtained using this method for shapes of finite dimensions with existing analytical solutions for shapes of infinite dimensions.