LOBO

Unanchored, round, flat floors and slabs without additional edge moment

Fig. 1 - Unanchored rectangular or elliptical slab presented from the inside without additional edge moment

Unanchored, round plates with additional edge moment

Fig. 3 - Unanchored circular plate with additional equidirectional edge moment

Fig. 4 - Unanchored circular plate with additional opposing edge moment

Table 1 - Calculation coefficients of unanchored, circular, plane floors and slabs without additional edge moment

Design
(schematic view only)

Requirements

Calculation coefficient C

a) carded flat bottom

1. brim radius:

Since	rMinimum dimension
up to 500	30
> 500 to 1400	35
> 1400 till 1600	40
> 1600 till 1900	45
> 1900	50
And r ≥ 1,3s

2. shelf height: h ≥ 3.5s (observe conditions from section 6.1.1!)

0,30

b) forged or pressed flat bottom

1. rim radius

but not less than 8 mm.

2. shelf height h ≥ s

0,35

c) plate welded on both sides

Plate wall thickness

s ≤ 3 s1

0,35

s > 3 s1

0,40

d) flat plate on a flanged joint with continuous gasket

D1 ≥ _Di

0,35

e) plane plate with relief groove ¹⁾

s1= designed wall thickness of the cylindrical part of the bottom adjacent to the cylindrical shell

1. residual wall thickness in the groove:

but not less than 5 mm

and for _Da> 1.2 D1 sR ≤ 0.77 s1

2. groove radius:

r ≥ 0.2 s, but not less than 5 mm and

3. only killed cast steels may be used. When using plates, the plate must not have any doublings in the area of the weld seam in a width of at least 3 s12^).

4. in the case of special stresses, e.g. in the creep range, this design is not suitable without special proof.

0,40

f) plate welded on both sides

Panel wall thickness:

s ≤ 3 s1

0,40

s > 3 s1

0,45

Only killed cast steels may be used. When using plates, the plate must not have doubles in the area of the weld in a width of at least 3 s1. ²⁾

g) flat plate freely supported on both sides

Residual wall thickness at gasket circle or in grooves

sR ≥ 0.7 s

0,40

h) plate welded on one side

Panel wall thickness:

s ≤ 3 s1

0,45

s > 3 s1

0,50

i) partially welded flat plate

Panel wall thickness:

s ≤ 3 s1

0,45

s > 3 s1

Conditions for a:

a ≥ 0.5 s and a ≥ 1.4 s1

Df /D1 ≥ 0.7

0,50

k) flat plate presented from the outside

1. residual wall thickness at the sealing circle:
sR ≥ 0.7 s

2. soft material seal
D1 ≤ 500 mm

1,25

l) flat plate presented from the inside

Residual wall thickness at the sealing circle:

sR ≥ 0.7 s

0,45

¹⁾Other cross-sectional shapes of the relief groove may be more stress-favorable and are permissible with the appropriate verification.

²⁾This is usually fulfilled if the tests have been carried out in accordance with the steel-iron delivery conditions DIN EN 10160 quality class E 3. This can already be agreed when the order is placed.

AD 2000 B5 Plate 1