grc screen lower
DESCRIPTION
Design of lowersTRANSCRIPT
PROJECT: DUBAI MALL FASHION AVENUE EXTENSION
LOCATION: DUBAI, UAE
SUBJECT: GRC SCREEN LOUVER
FIG. 1
1300
a a
The following calculation is for the panel at the location of the opening (of size 1300x1635).
This is an integral part of the overall panel.
b
b
1635
FIG. 2 section aa
FIG. 3
II GIVEN DATA
GRC UNIT WEIGHT = 2000 kg/m³
MODULUS OF ELASTICITY (E) = 6895 MPa
FOR THE SCREEN
GRC THICKNESS = 35 mm
LENGTH (Span)= 1635 mm
WIND PRESSURE = Wp = 3.16 kPa (Suction)
TRIBUTARY AREA = 1300x 1635= 2,125,500.00 mm²
2.1255 m²
LESS AREA OF OPENINGS = 1223675.77 mm²
1.224 m²
NET EFFECTIVE AREA Ag = 0.902 m²
NET AREA FACTOR = 0.902/2.1255 0.424
FOR THE SECTION OF THE SCREEN
N. Axis
c = 18.33 35 35
see at section bb COMPUTE THE M.I. (I) OF SECTION
Width of the panel = 1300 mm
Effective width after reduction of the openings
= 846 mm
Effective moment of Inertia
= 846 x 353
Fw 12
= 3,022,688 mm4
Wp = -3.16 kPa (Suction)
Effective wind pressure = Wp x Net area factor
= 3.16 x 0.424
= 1.340 kPa
Wind load per unit length = 1.340 x 1.3
= 1.742 kN/m
1635
V = w L/2 1424.09 N
118,000 Nmm
The panel is part of the overall panel and consequently, partial fixity condition at the edges are assumed.
M = wL² M = wL²
10 10
Nmm
BENDING
max M = 1.742 x 1.6352
10
= 0.466 kNm
= 465,676 Nmm
CHECK FOR BENDING STRESS AND SHEAR STRESS
fb = M c
I
465,676 x 18.33
fb = 2.82 N/mm²
3,022,688
465,676
ALLOWABLE BENDING STRESS OR FLEXURAL = 900 Psi (minimum)
6.2 N/mm²
fb IS LESS THAN ALLOWABLE, HENCE OK
SHEAR :
fv = V
A
fv = 1424.09 A = (35 x 35)x2 + (25 x 35) x 5
6825 6825 mm²
fv = 0.209 N/mm² OK
FOR ALLOWABLE SHEAR STRESS= 400 Psi
2.758 N/mm²
fv IS LESS THAN ALLOWABLE, HENCE OK
DEFLECTION
Max. Deflection = wl4
384 EI
= 1.56 mm
Allowable Deflection = span/200
= 8.175 mm
Maximum deflection is less than allowable. HENCE OKMaximum deflection is less than allowable. HENCE OK