Determinacion Sag

3. Materials

Steel
The constituent elements of the façade support anchors shall be manufactured from sheet steel and cold/hot rolled in general use in construction following the general rule UNEEN 10025 and particulars BS.

Standard referred to:
EN 10025:2004 Former references
Steel
grade Minimum yield strength ReH Tensile strength Rm Minimum elongation

F D GB B
N/mm2 N/mm2 % NF A35-501 DIN 17100 BS 4360 NBN
A21-101
Thickness
(mm) Thickness (mm) Thickness (mm)
16
> 16
40
3
100
3
40

S 235 JRG2 235 225 340-470 26 RSt 37-2 40 B
S 235 J0 235225 340-470 26 E 24-3 St 37-3 U 40 C AE 235-C
S 275 JR 275 265 410-560 22 E 28-2 St 44-2 43 B AE 255-B
S 275 J0 275 265 410-560 22 E 28-3 St 44-3 U 43 C AE 255-C
S 355 JR 355 345 490-630 22 E 36-250 B AE 355-B
S 355 J0 355 345 490-630 22 E 36-3 St 52-3 U 50 C AE 355-C
S 355 J2G3/G4 355 345 490-630 22 St 52-3 N 50 D AE 355-D


4. Loads
We consider the weight of the whole system:temporally mullion + winch.
- Temporally mullion: 90 kg
- Winch (+ chain): 100 kg




We are going to calculate the worst case scenario, checking deflections and stress situations are not going to beupper than the limits imposed by the material and the specific rules.

Dead Load:

The 250x150x12 steel transoms are supporting the mullion weight which has a weight of 20 Kg/m. Considering 4 mmullions:



Considering: safety factor, 1.40 (BS 5950)..

Load due to the pulley:



Load due to steel transom self weight:






This load value is applied in the middle of thesteel transom.


5. Analysis

Load on transom, case simply support beam, calculation expression for deflection in the center of the transom is:




= 4.29 mm, < L/1000 = 6 mm OK!. (NSSS)fmáx: maximum deflection (mm).
Q: total load: 5866 N
L: distance between fixing points (6,000 mm).
E: steel elastic modulus (210,000 N/mm2).
Imin: moment of inertia 2925 cm4

Safety factor is...