In this work several material failure criteria were researched including Tresca theory, von Mises theory and more. Also, more insight was gained about fracture mechanics tests such as single edge notch bend testing and compact tension testing. Compact tension test was chosen for the simulation of the fatigue crack growth rate. The Ansys static structural analysis was performed on a specimen with ASTM standard geometry and S275 structural steel was chosen from the library as the material. Tetrahedral mesh was generated and a pre-meshed crack was introduced at the notch. After applying the loads and boundary conditions to the model a simulation was created by Ansys Mechanical to simulate behavior of the specimen under a cyclic 200N load and relevant data such as the mode I stress intensity factor KI and crack extension was extracted. The crack length a, the number of cycles N and time obtained from the simulation and used to calculate the KI value using existing formulae. Then the KI values obtained from the simulation and by calculations were compared to show only minor differences. Thus, it can be concluded that Ansys enables for accurate and efficient trials. Due to computing power and meshing size limits, Ansys cannot always match the accuracy of tests conducted with real materials, but it can perform a large number of tests with various input data, such as geometries, loads, boundary conditions, or materials, reducing time and cost.