Issue 36

L. C. H. Ricardo et alii, Frattura ed Integrità Strutturale, 36 (2016) 201-215; DOI: 10.3221/IGF-ESIS.36.20

Figure 6 : FEM Model of CT specimen.

Figure 7 : FD&E SAE Suspension Modified Load History.

, followed by a single loading cycle

In the analysis, fatigue crack growth is simulated by releasing the crack tip node at P min

 P max

 P min,

P min

Fig. 7. The force is divided in nine steps between loads P min - P max

and nine steps between the P max

-P min

,

in each cycle. The smallest element size, 0.025 mm, was estimated based on the plastic zone size ( r p ) ahead of the crack tip and computed by Eq. (3.2). Only the first 20 reverses from load history shown in Fig. 7 were used to identify crack opening/closing and retardation effects.

P

a      

max



K

f

(3.1)

max

1

W BW

2

2

  

   

K

1

max

 

r

plane stress

(3.2)

p





y

where: K max

= maximum stress intensity factor;

P min P max = minimum applied load; = maximum applied load; B = specimen thickness; a = crack length; W = width of the specimen;

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