This paper proposes an innovative concept for the design of an experimental testing programme suitable for causing Low Cycle Fatigue crack initiation in a bespoke complex notched specimen. This technique is referred to as the Reversed Plasticity Domain Method and utilises a novel combination of the Linear Matching Method and the Bree Interaction diagram. This is the first time these techniques have been combined in this way for the calculation of the design loads of industrial components. This investigation displays the capabilities of this technique for an industrial application and demonstrates its key advantages for the design of an experimental testing programme for a highly complex test specimen

This paper investigates an approach for calculating the cyclic J-integral through a new industrial application. A previously proposed method is investigated further with the extension of this technique through a new application of a practical three-dimensional (3D) notched component containing a semi-elliptical surface crack. Current methods of calculating the cyclic J-integral are identified and their limitations discussed. A modified monotonic loading (MML) concept is adapted to calculate the cyclic J-integral of this 3D semi-elliptical surface crack under cyclic loading conditions. Both the finite element method (FEM) and the extended finite element method (XFEM) are discussed as possible methods of calculating the cyclic J-integral in this investigation. Different loading conditions including uniaxial tension and out-of-plane shear are applied, and the relationships between the applied loads and the cyclic J-integral are established. In addition, the variations of the cyclic J-integral along the crack front are investigated. This allows the determination of the critical load that can be applied before crack propagation occurs, as well as the identification of the critical crack direction once propagation does occur. These calculations display the applicability of the method to practical examples and illustrate an accurate method of estimating the cyclic J-integral.

This paper investigates an approach for calculating the cyclic J-Integral (ΔJ) through a new industrial application. A previously proposed method is investigated further with the extension of this technique through a new application of a practical 3D notched component containing a semi-elliptical surface crack.Current methods of calculating the cyclic J-Integral are identified and their limitations discussed. A modified monotonic loading method is adapted to calculate the cyclic Jintegral of this 3D Semi Elliptical Surface Crack under cyclic loading conditions. Both the finite element method (FEM) and the Extended Finite Element Method (XFEM) are discussed as possible methods of calculating the cyclic J-Integral in this investigation. Different loading conditions including uni-axial tension and out of plane shear are applied, and the relationships between the applied loads and the cyclic J-integral are established. In addition, the variations of the cyclic J-integral along the crack front are investigated. This allows the critical load that can be applied before crack propagation occurs to be determined as well as the identification of the critical crack direction once propagation does occur.These calculations display the applicability of the method to practical examples and illustrate an accurate method of estimating the cyclic J-integral.