302 / 392
Table 15. Diagnostical data for structural behaviour of excavator superstructure
σ
max
[kN/cm
2
]
memb/bend [%]
σ
/
τ
[%]
E
d
[%], [kNcm]
Existing Recons Existing Reconstr. Existing Reconstr. Existing Recon
Longitudinal
17
13
15.6/2.8 15.2/2.6
12.4/6
12/5.8
16.3
17.9
Cross Plate
17
11
7.7/1
8.9/1.2
4.5/4.3
5.4/4.6
4.6
4.2
Cylinder
22
13
7/2.3
5/1.9
5.6/3.5
4.4/2
4.8
4.2
Bottom Plate
22
16
14.9/1.5 13.7/1.3
13/3.5
11.5/3
19.2
17
Top Plate
20
14
12.9/2.4
12.7/2
12.2/3.1
11.5/3.2
17.5
17.6
Column
14
13
27.8/3.9 28.3/4.3 20.5/11.4 21.2/11.3
29.3
28.1
Beams
2.4/.4
3/0.1
8.3
11.
Sum
86.1/13.9 86.3/13.7 68.2/31.8
69/31
13500 11200
3.15. The analysis of crack significance on rotary furnace ring
Cracks had been detected on the ring of furnace No 3 in Cement Factory Beočin.
Crack significance analysis was required for the permission of continued service without
repair. Inner diameter of the ring is 6000 mm, and thickness of 350 mm (Fig. 40). The
ring 3D model is presented in Fig. 40, and the obtained displacement field in Fig. 41. The
fine volume model produced 25% higher stress compared to plane ring model (Fig. 42).
Simulated crack depth on the volume model was 10.7 cm. On the planar model the
simulated crack depth of 26.8 cm is accepted (10 cracks with a step of 2.68 cm). Structure
with initial crack
a
= 10.7 cm has been analysed in Fig. 43, and crack growth effects on
parameters of concern, including crack opening displacement (COD) and crack tip open-
ing displacement (CTOD) is presented in Fig. 44.
Figure 40. 3D coarse model of
furnace ring
Figure 41. Displacement field,
f
max
= 0.5 cm
(no crack)
σ
eq
= 0–4.25 kN/cm
2
, step 1, without crack
2D model
σ
max
eq
= 5.5 (10.5) kN/cm
2
298
Figure 42. Results for 2D ring model