Objectives:

To develop a 3-D strain concentration factor (SeCF) (Kte) equation for panels with countersunk rivet holes.

Approach:

Conducted an exhaustive 3-D finite element analysis of countersunk hole in a plate subjected to tensile loads. Countersunk angle and depth, plate thickness and width were varied for a wide range. Based on FE results and limiting conditions, a general equation for Kte was developed and verified.

Significance:

The equation would be a valuable tool for strain based design of structural elements. The Kte and Kt equations have similar form, and Kte <= Kt. The maximum difference between the two is 8% ( for v=0.3) or v²square for straight shank holes and is about v² for straight shank holes and is about v²/2 for countersunk holes.