Stress Analysis of Near Optimal Surface Notches in 3D Plates

This paper presents a method of using two-dimensional (2D) optimal notch shapes to create near optimal surface notches with various depth and aspect ratios in uniaxially loaded three-dimensional (3D) plates. Axisymmetric and elongated surface notches are created by rotating 2D optimal notch shapes about two types of fixed axes, a major reason being to enable the surface notches to be manufactured by elementary methods. Stresses in the surface notches are determined using intensive 3D finite element analyses. Axisymmetric notches show small reductions in local peak stress relative to spherical notches with the same bounding dimensions. Local peak stresses in elongated notches are reduced by up to 26% relative to comparable spherical notches. The given method and results are transferable for the initial design, re-shaping, and damage repair of components manufactured from any commonly used metal. In damage removal applications a significant advantage of both notch types over spherical notches is that they allow more material to be extracted for the same notch length and maximum depth.