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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.

LAU-7 missile launcher housings, which are fitted to most Royal Australian Air Force (RAAF) F/A-18A/B aircraft, can experience cracking in the guide rail. This paper covers the design, manufacture and validation of a life extension repair for cracked launcher housings. The repair development uses DSTO's rework shape optimisation technology and fatigue testing capabilities. The rework design reduces peak stresses by 33 %, resulting in significant fatigue life enhancements, as demonstrated by representative coupon testing. A special manufacturing jig has been designed and transitioned to the RAAF, which has used it to repair housings. These housings have performed well in flight tests, with no cracking detected.