Stress concentration due to a functionally graded ring around an elliptic hole in an infinite plate

This paper is to study the two-dimensional stress distribution of an infinite plate with a functionally graded annular ring around anelliptic hole based on complex variable method. With using the method of piece-wise homogeneous layers, the general solution for the functionally graded ring having normal arbitrary elastic properties is derived when the plate is subjected arbitrary constant loads at infinity, and then numerical results are presented for several special examples. It is found that the existence of the functionally graded annular ring influence obviously the stress distribution around the elliptic hole, and the stress concentration can be effectively reduced by choosing proper change ways of the normal elastic properties and proper thicknesses of the annular ring.