JOB NO 1220 DATE 21-Nov-2019 PAGE 1 OF 2
JOB NAMESEL MANUFACTURING DEGN BY KNK CHK BY GP
TITLE DESIGN OF PURLINS REV NO 0 Rev Dt
LOCATIONPURLIN - DESIGN -7.5 M - END BAY BULDG A
GIRT DATA :- BUILDING DATA :-
PURLIN SECTION Z200X1.75 WIDTH OF BUILDING : 35.00 M
SPAN OF THE PURLIN : 7.50 M INT PRESSURE CO-EFF : 0.20
ROOF SLOPE : 1:10 EXT. PRESSURE CO-EFF : 0.94
NO OF SAG RODS : 2 Nos. LOCAL CO-EFF : 0.00
PURLIN LAP : 353 mm YEILD STRENGTH : 344.7 N/mm2
CRITICAL SPACING EDGE STRIP : 1500 mm YOUNG'S MODULUS : 2.00E+05 N/mm2
CRITICAL SPAC. INTEROR STRIP : 1500 mm
ROOF ANGLE : 5.71 o
LOAD DATA :-
DEAD LOAD : 0.10 KN/m2, (Inclusive of Purlin/Girt self weight) 1.75 200
LIVE LOAD : 0.57 KN/m 2
DESIGN WIND PRESSURE : 0.80 KN/m2
UDL ON PURLINS :- Properties of Z200X1.75
DEAD LOAD :- Area 6.29 cm2
about X-X axis : 0.1x 1.5 x Cos 5.71 = 0.149 KN/m Ixx 377.01 cm4
about Y-Y axis : 0.1x 1.5 x Sin 5.71 = 0.015 KN/m Sx 37.70 cm3
LIVE LOAD :- : Rx 7.74 cm
about X-X axis : 0.57x 1.5 x Cos 5.71 = 0.851 KN/m Iyy 56.46 cm4
about Y-Y axis : 0.57x 1.5 x Sin 5.71 = 0.085 KN/m Sy 7.62 cm3
WIND LOAD :- Ry 2.99 cm
about X-X axis : 0.8 x ( 0.2 + 0 )x1.5 = 1.368 KN/m , as the Interior strip load is critical
LOAD CASES :-
Px Py
DEAD LOAD + LIVE LOAD = (0.149 + 0.851) = (0.015 + 0.085)
= 1.000 KN/m = 0.100 KN/m
DEAD LOAD + WIND LOAD = ( 1.368 - 0.149) x 0.75 = (0.015 + 0) x 1.0
(Considering 33% inc. of Stress) = 0.914 KN/m = 0.015 KN/m 1.000 KN/m
LOADING DIAGRAM :-
A 7500 B 7143 7143 D 7143 E
Ra=2.95 KN Rb=8.57 KN Rc=6.96 KN Rd=6.96 KN Re=6.96 KN
(0.393 wl) (1.143 wl) (0.928 wl) (0.928 wl) (0.928 wl)
SF DIAGRAM :-
(0.393 wl) (0.536 wl) (0.464 wl) (0.464 wl) (0.464 wl)
2.95 4.02 3.48 3.48 3.48
4.55 3.48 3.48 3.48
(0.607 wl) (0.464 wl) (0.464 wl) (0.464 wl)
BM DIAGRAM :-
(-0.1071 wl2) (-0.0714 wl2) (-0.0714 wl2) (-0.0714 wl2)
-6.02 -4.02 -4.02 -4.02
2.05 2.05 2.05
4.34 (+0.0364 wl )
2
(+0.0364 wl ) 2
(+0.0364 wl2)
(+0.0772 wl )
2
1 KN/m
DESIGN MOMENTS :-
Major axis Bending - Mxx : 4.34 KN-M, @ Mid span 6.02 KN-M
Major axis Bending - Mxx : 6.02 KN-M, @ Support
Moment at end of lap - Mxx: 6.02 + 1 x0.353^2/2 - 4.55x0.353 0.353 M
: 4.48 KN-M 4.55 KN
Shear force along y dirn. -Pv: 4.55 KN Free body diagram
Minor axis Bending - Myy : 0.080 KN-M
designed by deepee
JOB NO 1220 DATE 21-Nov-19 PAGE 2 OF 2
JOB NAMESEL MANUFACTURING DEGN BY KNK CHK BY GP
TITLE DESIGN OF PURLINS REV NO 0 Rev Dt
LOCATIONPURLIN - DESIGN -7.5 M - END BAY BULDG A
ACTUAL BENDING STRESS :-
Actual Stress major axis -s bc.cal-xx = Mxx / Sx = 4.48 x 10^6 / 37.7x 10^3 , as the support moment governs
= 119 N/mm 2
Actual Stress minor axis -s bc.cal-yy = Mxx / Sy = 0.08 x 10 ^ 6 / 7.62x 10 ^ 3
= 11 N/mm2
ALLOWABLE BENDING STRESS :-
Un supported Length L = 162 cms , distance from support to point of contraflexure
Co-efficient of Bending Cb = 1.75 + 1.05 (M1/M2) + 0.3 (M1/M2) 2 , subject to a min. of 1.00 & max of 2.3
= 1.75 , as the simply supported end moment is zero
Parameters :-
As Iyc = Iyy / 2 = 28.23 cm4
L2 x Sxc / d Iyc = 162^2 x 37.7 /20 x 28.23
= 1402
0.18 x P2 x E x Cb / Fy = 0.18 x 3.142^2 x 2.05x10^5 x 1.75 / 345
= 1848
0.90 x P2 x E x Cb / Fy = 0.90 x 3.142^2 x 2.05x10^5 x 1.75 / 345
= 9237
Allowable Bending Stress F= 2/3 Fy - Fy^2 / (2.7xPi^2x E x Cb ) x ( L^2 Sx / d Iyc )
= 2/3 x 345 - 345^2 / 2.7x3.142^2x2x10^5x1.75) x ( 1402)
= 212.11 N/mm2
Allowable Bending Stress F= 0.6 Fy
= 207 N/mm2
RATIO :-
s bx/Fbx + s by/Fbx = 119/207 + 11/212.11
= 0.63 < 1, Hence Safe
SHEAR STRESS :-
Actual Shear Stress :-
Actual Shear Stress, fv = Pv / (d x t)
= 464 / (20x0.175)
= 133 Kg/cm2
Allowable Shear Stress :-
Parameters :-
d/t = 20 / 0.175
= 114.285714
4590 / Sqrt (Fy) = 4590 / Sqrt(3447)
= 78
Allowable Shear Stress, Fv = 5 850 000 / (d/t)^2 ,as d/t > 4590/Sqrt(Fy)
= 5850000 / (114.285714285714*114.285714285714)
= 448 Kg/cm2 > 133 Kg/cm^2, Hence Safe
DEFLECTION :-
Actual Deflection = 0.0065wl4/EI , at 0.44 L
= 0.0065 x 1.219 x 7500^4 / 200000 x 377.01 x 10E04
= 34 mm, @ 3300 from the end support
Allowable Deflection = Span / 180
= 7500 / 180
= 42 mm > 34 , Hence Safe
designed by deepee
