purlinsa requisition is a request for something, especially a formal written request on a...
DESCRIPTION
A requisition is a request for something, especially a formal written request on a pre-printed form.An online requisition is an electronic document, which can be originated by the requester and then using the company workflow or hierarchy rules, can be submitted to the subsequent levels, until it is finalized or approved and then converted to a purchase order. While reviewing the electronic requisition, the reviewer should have the ability to check different parameters of the requisition with regard to the inventory levels and financial controls.Requisitioning is sometimes a compulsory act similar to expropriation; for example in wartime some governments may (compulsorily) requisition what they need.A requisition is used in business as an internal document used to notify stores or the purchasing department of items that are needed or need to be ordered. It sets out the quantity and the time frame. It may also contain the authorization to proceed with the purchase if the required items are not available in stock.Medical requisition is generally referred to a process by which clinicians (physicians, physician assistants, pharmacists and nurses, etc.) place orders for medical diagnostic tests, medical equipment, radiology exams and oTRANSCRIPT
DESIGN OF PURLINS Sheet Content: Preliminary Data Sheet 1 of 28
PRELIMINARY DATA
Roof Data
Roof Angle 10.22
Roof Span 15 m
Spacing of Purlins 0.9 m
Length of Purlins 6 m
Material Type Weight Reference
Roofing GA 24 pre-
painted rib type roofing
1.3 psf Weight of
materials from:
www.pole-
barn.info
Insulation Fiberboard 1.5 psf
Conversion of Roofing and Insulation Weight to metric:
Roofing:
Insulation:
Trial Section: LC 175 x 50 x 20 x 2
mass in kg/m=4.68kg/m Sx = 30x103 mm3 Sy =5.5x103 mm3 (ASEP STEEL HANDBOOK)
DESIGN OF PURLINS Sheet Content:Loadings Sheet 2 of 28
LOADINGS
DESIGN OF PURLINS Sheet Content: Loadings Sheet 3 of 28
Dead Loads
Roofing (N/m) Weight of roofing x purlin spacing 71.85 x .9 =64.67 N/m
Insulation(N/m) Weight of insulation x purlin
spacing 62.67 x .9 =56.40 N/m
Total 121.07 N/m
Self Weight(N/m) Mass of purlin x gravity constant 4.68x 9.81=45.91 N/m
Live Loads
ROOF SLOPE: rise/run; 2.705/15
18.03%
Reference
Table 205-3
NSCP
Flat or rise less than 4 units vertical in 12 units horizontal
(33.3% slope). Arch and dome with rise less than one-eight of
span.
Tributary Area
95 m²
Uniform load (kPa)
0.6
Roof Live Load (N/m) Live load pressure x purlin spacing 540 N/m
DESIGN OF PURLINS Sheet Content: Wind Load Cases Sheet 4 of 28
WIND LOAD CASES
NORMAL TO RIDGE
(+GCpi)
(-GCpi)
38.06
DESIGN OF PURLINS Sheet Content: Wind Load Cases Sheet 5 of 28
WIND LOAD CASES
PARALLEL TO RIDGE
(+GCpi)
(-GCpi)
CRITICAL WIND PRESSURES
(+GCpi) (-Gcpi)
Wind Normal to the Ridge:
Windward: -863.932 -458.665
Leeward: -498.214 -92.947
Wind Parallel to the Ridge: -1063.824 -658.558
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 6 of 28
NORMAL AND TANGENTIAL LOADS OF DIFFERENT LOAD COMBINATIONS
D+W CASE 1:NORMAL TO RIDGE WINDWARD (+GCpi)
WINDLOAD=(863.93 N/m2)(.9 m)=777.54 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 7 of 28
D+W CASE 2: NORMAL TO RIDGE WINDWARD (-GCpi)
WINDLOAD=(458.67 N/m2)(.9 m)=412.80 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 8 of 28
D+W CASE 3:NORMAL TO RIDGE LEEWARD (-GCpi)
WINDLOAD=(498.21 N/m2)(.9 m)=448.39 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 9 of 28
D+W CASE 4:NORMAL TO RIDGE LEEWARD (-GCpi)
WINDLOAD=(92.95 N/m2)(.9 m)=83.66 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 10 of 28
D+W CASE 5:PARALLEL TO RIDGE (+GCpi)
WINDLOAD=(1063.83N/m2)(.9 m)=957.45 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 11 of 28
D+W CASE 6:PARALLEL TO RIDGE (-GCpi)
WINDLOAD=(658.56/m2)(.9 m)=592.70 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: Normal and Tangential Loads of Different Load Combinations Sheet 12 of 28
D+L WINDLOAD=(658.56/m2)(.9 m)=592.70 N/m
NORMAL COMPONENT
TANGENTIAL COMPONENT
AT TOP AT CENTROID
DESIGN OF PURLINS Sheet Content: PURLINS WITHOUT SAGROD Sheet 13 of 28
CASE 1: NO SAGROD
LOAD COMBINATION D+W
CASE 1
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 2
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITHOUT SAGROD Sheet 14 of 28
CASE 3
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 4
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 5
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 6
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITHOUT SAGROD Sheet 15 of 28
D+L COMBINATION
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITHOUT SAGROD Sheet 16 of 28
LOAD COMBINATION ACTUAL STRESS (MPa) ALLOWABLE STRESS
(Mpa)
D+W
CASE 1
PASS
CASE 2
PASS
CASE 3
PASS
CASE 4
CASE 5
PASS
CASE 6
PASS
D+L
FAIL
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT MIDPOINTS Sheet 17 of 28
CASE 2 : PURLINS WITH SAGROD AT MIDPOINTS
LOAD COMBINATION D+W
CASE 1
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 2
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT MIDPOINTS Sheet 18 of 28
CASE 3
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 4
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 5
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 6
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT MIDPOINTS Sheet 19 of 28
D+L LOAD COMBINATION
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT MIDPOINTS Sheet 20 of 28
LOAD COMBINATION ACTUAL STRESS (MPa) ALLOWABLE STRESS
(Mpa)
D+W
CASE 1
PASS
CASE 2
PASS
CASE 3
PASS
CASE 4
CASE 5
PASS
CASE 6
PASS
D+L
PASS
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT THIRD POINTS Sheet 21 of 28
PURLINS WITH SAGROD AT THIRD POINTS
LOAD COMBINATION D+W
If
The maximum moment is at third point, Otherwise, the moment is at midspan
Therefore, the maximum moment is at third points
CASE 1
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 2
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT THIRD POINTS Sheet 22 of 28
CASE 3
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 4
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 5
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
CASE 6
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT THIRD POINTS Sheet 23 of 28
LOAD COMBINATION D+L
MAXIMUM MOMENT
NORMAL COMPONENT
TANGENTIAL COMPONENT
At Top
At Centroid
DESIGN OF PURLINS Sheet Content: PURLINS WITH SAGROD AT THIRD POINTS Sheet 24 of 28
LOAD COMBINATION ACTUAL STRESS (MPa) ALLOWABLE STRESS
(Mpa)
D+W
CASE 1
PASS
CASE 2
PASS
CASE 3
PASS
CASE 4
PASS
CASE 5
PASS
CASE 6
PASS
D+L
PASS
Based on the calculations presented it is recommended to use LC 175 x 50 x 20 x 2 section of purlin with sagrods at third points.
SAGRODS AT MIDSPAN
LOAD COMBINATIONS
D+W
(Tangential forces at top of the purlin)
(Reaction of sag rod)
(Total Reaction of sagrod)
(Cross sectional area of sagrod)
(Diameter of sagrod)
D+L
(Tangential forces at top of the purlin)
(Reaction of sag rod)
(Total Reaction of sagrod)
(Cross sectional area of sagrod)
(Diameter of sagrod)
DESIGN OF PURLINS Sheet Content: CONCLUSION AND DESIGN OF SAGROD Sheet 25 of 28
CONCLUSION
DESIGN OF SAG ROD
SAGRODS AT THIRD POINTS
LOAD COMBINATIONS
D+W
(Tangential forces at top of the purlin)
(Reaction of sag rod)
(Total Reaction of sagrod)
(Cross sectional area of sagrod)
(Diameter of sagrod)
D+L
(Tangential forces at top of the purlin)
(Reaction of sag rod)
(Total Reaction of sagrod)
(Cross sectional area of sagrod)
(Diameter of sagrod)
DESIGN OF PURLINS Sheet Content: DESIGN OF SAGROD Sheet 26 of 28
DESIGN OF PURLINS Sheet Content: DESIGN OF TIEROD Sheet 27 of 28
DESIGN OF TIE ROD
TIE ROD FOR SAGROD AT MIDSPAN
FORCE TRIANGLE ANALYSIS COMPUTATION
RTOTAL
10.22
P
DESIGN OF PURLINS Sheet Content: DESIGN OF TIEROD Sheet 28 of 28
TIE ROD FOR SAGROD AT THIRD POINTS
FORCE TRIANGLE ANALYSIS COMPUTATION
RTOTAL
10.22
P
