PSI - Issue 39

Davide Leonetti et al. / Procedia Structural Integrity 39 (2022) 9–19 Author name / Structural Integrity Procedia 00 (2019) 000–000

16 8

3.2. Stress Intensity Factors due to the moving load In this section, the SIFs derived following the depicted procedure is qualitatively compared with the SIFs from FE simulations carried out by Bogdansky (1999), which are related to RCF crack ( ω= 75°, a/W=0.36) loaded by a rolling disk moving on top of a plate hinged on the other sides. The tangential load is applied considering a full stick behavior, i.e. q(s)=- μ p(s) , where μ =0.4 is the Coulomb friction coefficient. Moreover, a frictional behavior was set for the contact between the plate and the disk. The parameters D n ij for the considered geometry are required in order to determine the weight functions, using the Green’s functions. These are calculated using a finite element model. 3.2.1. Green’s functions for the reference case The Green’s functions for the reference case are derived using a finite element model of a finite width plate containing an inclined edge crack, following the mechanical scheme of Figure 1. As mentioned in Section 2.1 four reference cases are required to derive the weight functions according to the format proposed by Fett (1997), these are depicted in Figure 6.

a

a

Q

P

-P

-Q

ω

ω

W

W

5W

5W

a

a

Q

P

ω

ω

-P

-Q

W

W

5W

5W

Fig. 6. Reference load cases

(a) Control volume

(b) Crack tip mesh

Fig. 7. Mesh of the crack