286 / 392
Figure 4. Fine model of excavator bogie
Figure 5. Stress field of bogie 0–28.3 kN/cm
2
Table 1. Contribution of stresses and strains in the bogie for base/modified model
Stress distribution
[
%
]
Base/modified model
Membrane Bending
Distribution of
strain energy
[
%
]
Upper horizontal plate
14.7/14.8
7.0/10.9
16.1/20.4
Lower horizontal plate
15. /15.7
6.2/6.3
18.7/20.9
Cilinder + saw-plate
18.7/15.5
12.8/8.3
18.7/12.6
Vertical plates
16.0/21.1
3.7/5.1
34.2/43.6
Flange
0.9/0.6
4.9/1.6
12.3/2.5
Total
65.3/67.7
34.7/32.3
100./100.
3.3. Failure anlysis of the radi-axial bearing of the rotary excavator C700S
During the warranty period, in service, radial-axial bearing of 5 m diameter failed due
to damage of fixing on bucket wheel excavator C700 (Kolubara Metal Vreoci). The
designer stated that the reason of failure was incomplete welding of diaphragms on the
bogie. Finite element computation (Fig. 6) showed, apparently, that he was wrong and
Kolubara-Metal had been released with significant expenses.
Analyses of the stress field (Fig. 7) showed presence of 16% bending stress in the
computation model with 6 DOF and 11% in the reduced model (based on verified good
concept of designed geometry). Large strain and stress concentration is found around
supports. Obtained results showed
that the effect of improper welding was negligible.
Figure 6. Model of excavator bogie C700S
Figure 7. Stress field
282