IFMASS8

A typical example is a plate of dimensions 100

100

1 cm with central through-crack

exposed to nominal tensile stress of 10 kN/cm

. The model of the cracked plate and stress

field component distribution are shown in Fig. 1 for crack length of 25 mm. The depen-

dence of different parameters on crack length is presented in Fig. 2.

In case of an embedded crack the computational model has to be of volume-type (see

Fig. 3). The crack effect has to be considered in two directions (crack length and depth).

Figure 3. Computational volume model for a plate containing an embedded crack

3.2. Behaviour diagnostics of the rotary excavator bogie (FC Beocin)

Frequent cylinder failures of the support excavator SH400 in the Cement factory (FC)

– Beočin, located beneath the flange of the radial-axial bearing (diameter

= 2.5 m) have

caused bearing destruction, requiring behaviour diagnostics. Existent behaviour diagnos-

tics were extended with the determination of flange warping. It has been shown that the

bogie of the rotary excavator is exposed to very unfavourable stress and strain fields.

The base fine model (Fig. 4) verified the existance of stress-concentration. The stress

value in the cylinder increased from 14 to 24.5 kN/cm

and in vertical plates from 10.5 to

28.3 kN/cm

(Fig. 5 and Table 1). Maximal deformation increased from 3 to 6.9 mm, and

warping value from 0.3 to 0.75 mm. These values have substantially exceeded allowable

values. The bogie modification could be done by adding the saw-plate between the

cylinder and flange. The application of the saw-plate efficiently eliminates unfavourable

behaviour of the cylinder and flange without perturbation of global behaviour of the

considered construction.

281