Issue 53

A. Chatzigeorgiou et alii, Frattura ed Integrità Strutturale, 53 (2020) 306-324; DOI: 10.3221/IGF-ESIS.53.24 316 V ERIFICATION OF THE CODE n this chapter, a comparison of the results of the calculation of the SIFs, with the results from an analytical method, is presented. In addition, is expounded the comparison of the trajectory and the fatigue lifetime estimation of the crack, created by the code and FEMAP, with results from an experiment, in order to check the accuracy and the percentage deviation. Calculation of Stress Intensity Factors. In order to check the results of the calculation of the SIF from the code, an analytical expression was used [29]. For the calculation of   and I   , the following equations were used:   I K C      (13)   2 3 4 1.12 0.231 10.55 21.72 30.39 C             I K C       (14)   2 3 4 5 4.886 11.383 28.198 38.563 20.555 C            where w    α = crack length W = breadth of the cracked plate According to Eqn. (13) and Eqn. (14), the plate shown in Fig. 13 with the characteristics from Tab. 3, was used, in order to calculate analytically the SIFs. The results are shown in Tab. 4 with the crack length α equal to 5mm. Figure 13: Lode case for K I (a) and K II (b). Taking into consideration the analytical solution, five FEMAP models were created. All models were considered to be in plane strain condition. Every model has a different number of contours, in order to check whether the results are affected by locally changing the mesh at the crack tip. The first model has one contour and the fifth has five. The global mesh size is 0.5mm. In Fig.14 is presented a cracked model with two contours (outside the Crack Tip Elements). I