A FE based numerical tool for crack assessment in ship structures employing the CSR loading scheme

Among the most common defects found in ship structures, which potentially could lead to criti-cal loss of structural integrity, are cracks. A methodology is proposed that combines the Common Structural Rules (CSR) fatigue loadings with the Finite Element Method (FEM) for the study of cracks on actual marine structure subjected to high-cycle low-stress fatigue. The aim is to establish a common base for evaluating dif-ferent crack arrest technologies. To this end a three-compartment model of an Aframax tanker was created us-ing the FEM and following the guidelines proposed by the CSR. The structure was subjected to fatigue loads and different crack scenarios were investigated for two loading conditions. The stress intensity factors were calculated and by using the well-known Paris law formula an estimation of the crack growth rate was derived. The proposed method is simple and based on rules and regulations widely accepted in the ship industry.