Purlins and Girts. A division of Canam Group

Transcription

1 Purlins and Girts A division of Canam Group

2 TABLE OF CONTENTS OUR SOLUTIONS AND SERVICES Cautionary statement INTRODUCTION Advantages High-performance steel Design Tolerances Complete fabrication services LATERAL STABILITY OF PURLINS Through-fastened roof Standing seam roof Definition of discrete bracing Anchorage of purlin bracing (anti-roll safeguard) Plan view of purlin bracing locations per bay Sample calculations Metric Loads on discrete bracing lines Metric Table 1 Z sections on a 2/12 roof pitch Table 2 Z sections on a 4/12 roof pitch Table 3 C sections on a 2/12 roof pitch Table 4 C sections on a 4/12 roof pitch C SECTIONS New nomenclature Properties Metric Selection table for factored loads Metric Properties Imperial Selection table for factored loads Imperial Fabrication tolerance Z SECTIONS New nomenclature Properties Metric Selection table for factored loads Metric Properties Imperial Selection table for factored loads Imperial STANDARD FEATURES OF C AND Z SECTIONS Assembly holes Sag rod holes Fabrication marks Overlapping Z sections CONNECTION DETAILS AND ACCESSORIES Interior girt to column connection details Interior girt to corner column connection details Exterior girt to corner column connection details D view of building corner column Frame attachment angles Angle closures APPENDIX 1 Cutting list (order form) APPENDIX 2 Fabrication details (order form) BUSINESS UNITS AND WEB ADDRESSES PLANTS AND SALES OFFICES ADDRESSES Canam is a trademark of Canam Group Inc. 3

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4 OUR SOLUTIONS AND SERVICES Canam Canada specializes in the fabrication of steel joists, joist girders, steel deck, and purlins and girts used in the construction of commercial, industrial, and institutional buildings. We offer customers value-added engineering and drafting support, architectural flexibility, and customized solutions and service. Canam Canada is one of the largest steel joist fabricators in North America. Because product quality, job site management and timelines are critical to the execution of any project, big or small, our reliability makes life easier for our customers. From design to delivery, our products stand out in terms of their exceptional quality. It should therefore come as no surprise that, thanks to our cutting-edge equipment, skilled employees and top-quality products, Canam Canada always delivers on its promises. Whatever the nature or scope of your project, we will meet your requirements and comply with all building codes applicable in your area. At Canam Canada, we know that, for our customers, time is money. This is why we have developed a rigorous job site management process to ensure that deadlines are met, period. To further streamline this process, our fleet of trucks stands ready to assure on-time delivery, regardless of the location. CAUTIONARY STATEMENT Although every effort was made to ensure that all data contained in this catalog is factual and that the numerical values are accurate to a degree consistent with current cold-formed steel design practices, Canam Canada does not assume any responsibility whatsoever for errors or oversights that may result from the use of the information contained herein. Anyone making use of the contents of this catalog assumes all liability arising from such use. All comments and suggestions for improvements to this publication are appreciated and will receive full consideration in future editions. 5

5 INTRODUCTION Purlins and girts are complementary products to structural steel and used primarily in the walls and roof of a building. All purlins and girts are cold-formed using high-performance steel in order to minimize weight while maximizing capacity. As with all Canam Canada products, our purlins and girts meet strict quality standards. Canam Canada fabricates a complete range of C and Z sections for use as purlins and girts at its plant in Boucherville, Quebec. The nominal depth of these sections varies from 6 inches (152 mm) to 14 inches (356 mm). ADVANTAGES Our automated equipment eliminates waste by cutting sections to exact length, which results in substantial cost savings for our customers. We can also manufacture sections according to your shop drawings. Canam Canada can equally apply a coat of red or grey primer to cold-formed sections according to the specifications of CPMA Standard 1-73A. This service is offered at a competitive price. HIGH-PERFORMANCE STEEL All purlins and girts are cold-formed from high-strength steel in order to minimize weight while maximizing capacity. The steel used to fabricate such members complies with the requirements of ASTM Standard A1011 HSLAS Grade 50. DESIGN The capacity of all Canam Canada cold-formed C and Z sections complies with the requirements of the CAN/CSA- S136-M07 North American Specification for the Design of Cold Formed Steel Structural Members with a material grade of 345 MPa (50 ksi). TOLERANCES The fabrication tolerances of all Canam Canada coldformed C and Z sections comply with those specified in the ACNOR CAN/CSA-A660-M04 standard for the Certification of Manufacturers of Steel Building Systems. Material thickness tolerances comply with standard ACNOR CAN/CSA-S136-M07. COMPLETE FABRICATION SERVICES In addition to our standard cut-to-length, punching and painting services, Canam Canada is now pleased to offer customers a turnkey fabrication solution for purlins and girts. The installation of connections and punching is performed at our plant according to your shop drawings. Customers who entrust the fabrication of their purlins and girts to Canam Canada benefit from multiple advantages: A finished product that is delivered directly to the job site Time savings (no changes or deliveries to the customer s facility) Lower manpower costs Reduced shipping and handling costs (no deliveries to the job site from the customer s facility) To obtain a quote or for additional information, please contact one of our sales representatives. 6

6 LATERAL STABILITY OF PURLINS THROUGH-FASTENED ROOF The use of a through-fastened roof does not preclude the need for proper purlin bracing. The roof structure can provide lateral stability but supplies no torsional stability whatsoever for Z or C sections. Discrete bracing should therefore be incorporated in the design phase in order to control torsional flexural buckling. DEFINITION OF DISCRETE BRACING A discrete brace can take a multitude of different forms as seen in the figures below. All of these types of bracing are discrete because the movement is controlled only at the particular brace point (Galambos 1998). The required bracing force and stiffness for this type of brace is dependant upon the number of braces provided STANDING SEAM ROOF The use of a standing seam roof does not preclude the need for adequate purlin bracing. The roof structure can only provide partial lateral stability and supplies no torsional stability whatsoever for Z or C sections. Discrete bracing should therefore be incorporated in the design phase in order to control torsional flexural buckling. EXAMPLES OF LATERAL STABILITY: TYPE 1 Symmetrical about the ridge Purlin brace Ridge brace TYPE 2 Symmetrical about the ridge Ridge channel Cope angles at top flange Angle cross brace at eaves Angle top and bottom (typical) Fasteners at each purlin (typical) Eave strut 7

7 LATERAL STABILITY OF PURLINS TYPE 3 Symmetrical about the ridge Steel deck Channel bracing Eave strut Ridge channel C section for discrete bracing Clip angle Purlin Structural bolts ANCHORAGE OF PURLIN BRACING (ANTI-ROLL SAFEGUARD) If no discrete bracing line is used, anchorage is required at each purlin support, which must be designed to resist in-plane forces. In certain instances, anti-roll clips may also be necessary. EXAMPLES: Purlin Anti-roll clip Structural fastener Purlin Shop weld Structural fastener Anti-roll stiffener Purlin Shop weld Anti-roll U section Structural fastener Horizontal plate Horizontal plate Structural bolts Structural bolts Structural bolts If one or more discrete bracing lines are used between purlin supports, the supports must be designed to resist in-plane forces as explained in the paragraph above. Substantial anchorage is required for the discrete bracing line at each eave and ridge end. The applied load on each line can be calculated according to standard S136. 8

8 LATERAL STABILITY OF PURLINS EXAMPLES: Purlin X purlin brace Single purlin brace NOTE: The purlin bracing is always installed in the same way regardless of the secondary member being used, including C and Z sections, struts, angles, etc. A A Single purlin brace (every other span) (1) Fastener Steel deck roof Single purlin brace Purlin X purlin brace (1) Fastener VIEW A-A PLAN VIEW OF PURLIN BRACING LOCATIONS PER BAY 1) A minimum of two rows of purlin bracing is required for long spans, regardless of the length of the bay (see the tables on pages 13-16). 2) The purlin bracings are spaced as shown in the diagram below. Rafter Purlin Rafter Purlin Single purlin brace Purlin lap Single purlin brace Purlin lap X purlin brace X purlin brace 0.38 x span 0.24 x span 0.38 x span = = = = Span Span Spacing for two rows Spacing for three rows Location of purlin bracing on a pitch 2/12 9

9 LATERAL STABILITY OF PURLINS SAMPLE CALCULATIONS METRIC Snow load = 2.4 kpa Wind pressure = 0.6 kpa Dead load = 1 kpa 8,000 mm 7 spaces of 1,100 mm Ridge channel Z section Wind (uplift) = 1.2 kpa 12 2 Example: Single span of Lx = 6,000 mm with a 1,100 mm spacing between Z sections. There are 9 sections (7 spaces of 1,100 mm) per building slope with a roof pitch of in 250 mm (angle of a = 9.46 degrees). The sloped length of one side is 8,000 mm with 300 mm between the ridge and the last section. Loads: Dead load (dl) of 1.0 kpa Snow load (sl) = 2.4 kpa Gross wind load in pressure (wp) = 0.6 kpa and 1.2 kpa of wind uplift (wu) STEP 1: CALCULATION OF Z SECTION WN AND WT LOADS FOR EACH LOAD wn dl = dl cos (a) Spacing = 1.09 kn/m wn sl = sl [cos (a)] 2 Spacing = 2.57 kn/m wn wp = wp Spacing = 0.66 kn/m wn wu = wu Spacing = 1.32 kn/m } wn wt dl = dl sin (a) Spacing = 0.18 kn/m wt sl = sl [sin (a)] 2 Spacing = 0.07 kn/m } wt STEP 2: LOAD COMBINATIONS ACCORDING TO THE 2005 NATIONAL BUILDING CODE Gravity: the greater of: 1.25 wn dl wn sl wn wp = 5.48 kn/m control 1.25 wn dl wn sl wn wp = 3.57 kn/m total wn = 5.48 kn/m total wt = 0.33 kn/m Uplift: 0.90 wn dl 1.4 wn wu = 0.87 kn/m 10

10 LATERAL STABILITY OF PURLINS STEP 3: CALCULATION OF LOADS ACCORDING TO WT AND WN Single span: Mf x = total wn Lx 2 / 8 = kn m Mf y = total wt Lt 2 / 8 = 0.37 kn m Where: Lt is the maximum distance between supports where discrete bracings are found. Assumption: According to the Canam table, one row of local lateral restraints at regular intervals, therefore, Lt = 3,000 mm. Vf = total Wn Lx / 2 = kn Mf uplift = uplift Lx 2 / 8 = 3.92 kn m STEP 4: PRELIMINARY CHOICE OF A SECTION Choice: new nomenclature: 305Z76-326M; former nomenclature: Z305x14 Assumption: the roof deck only partially maintains the compression flange on the Z section with a standing seam roof. Connections every 610 mm c/c provide only partial lateral support. Calculation of the moment under gravity loads Value of the Canam table (Mu) for Lt = 3,000 mm = 26.5 kn m Mrx = Mu Mry = 0.9 Sy Fy = 6.77 kn m where Sy = 21.8 x 10 3 mm 3 and Fy = 345 MPa according to the Canam table Interaction equations Mfx / Mrx + Mfy / Mry = 0.99 <= 1 ACCEPTABLE Calculation of the moment under uplift loads Mr uplift = Value of the Canam table (Mu for Lt = 3,000 mm) = 26.5 kn m Note: local lateral restraints can be used for uplift. Mf uplift / Mr uplift = 0.15 <= 1 ACCEPTABLE Calculation of shear (worst case scenario is shear near the support) Vr = Value of the Canam table (Vr) = kn Vf / Vr = 0.18 <= 1 ACCEPTABLE Calculation of web crippling with 100 mm of bearing Pr = Value of the Canam table (Pr) = kn Pr reduced because of the pitch = Pr [sin (90 a)] 2 = kn Vf / Pr reduced = 0.68 <= 1 ACCEPTABLE Reinforcement between the bearing and the support in the section s web is therefore not required in this step. Calculation of deflection I min (deflection < span / 180) = 180 x 5 x (wn sl + wn wp) x Lx 3 / (384 x 200,000 MPa) = x 10 6 mm. The Ix inertia of section 305Z76-326M according to the catalog is 22 x 10 6 mm 4 greater than the minimum inertia. Section 305Z76-326M (Z305x14) is acceptable. 11

11 LATERAL STABILITY OF PURLINS STEP 5: DESIGN OF THE ROW OF BRACING MEMBERS AND THE RIDGE CONNECTION According to the information in table 1 on page 13, the factored vertical load of a 6,000 mm purlin with a 2/12 pitch and a bracing line is 0.367/section/1.0 kn/m. The axial load of 8 sloped sections with a factored vertical load of 5.48 kn/m is: x 8 purlins per slope x 5.48 kn/m = 16.1 kn factored/bracing line. The local lateral restraint must be sized from top to bottom to transfer this load. In our example, the pitch is 2/12, the lateral restraint could be an angle welded from top to bottom with a cross bridging weld every 3 spaces from top to bottom. Other types of lateral restraint can also be used (see the beginning of the present section). In our example, the 16.1 kn load will be offset by the component connecting the Z section on each side of the ridge. The sizing of this part must be designed to achieve 16.1 kn where the section will be attached. STEP 6: DESIGN OF SUPPORTS ACCORDING TO THE PN EFFORT The Pn effort per section in each top flange above the support is 2.01 kn, which is equivalent to (as indicated in table 1 on page 13) multiplied by 5.48 kn/m. The moment developed in the section is equal to Pn x height of the section = Mf support = 2.01 kn x 305 mm = kn mm. Mr support = 0.9 x (Sx) x Fy = 0.9 x [(width at the bearing) x (thickness of the section) 2 /4] x = kn mm Where: width at the bearing = height of the section in mm. Mf> Mr NOT ACCEPTABLE. According to Step 4, an anti-roll clip must be installed between the web and the support. Two options are possible at this stage: the use of either a stiffener or an angle of suitable thickness (see page 8 for examples of anti-roll stiffeners). If an angle is used, it must have a minimum thickness of 8 mm by 200 mm wide and 200 mm high, which is equivalent to Mr = 864 kn mm. The use of this option presumes that only the angle is connected to the support. The choice of a 75 mm long by 200 mm high by 3 mm thick bearing stiffener would allow for a 200 mm wide by 200 mm high by 3 mm thick angle, which is lighter. General notes: In the example above, the use of only one local lateral restraint slightly increases the weight of the Z section. However, the second discrete bracing line could have a greater impact. Consider the results with 2 rows: 2 discrete bracing lines with the same pitch: 254Z76-290M with a Pn = of the table x 8 x 5.48 kn/m = 7.3 kn/bracing line. Note that if no discrete bracing line had been used in this second example, it would not be considered acceptable even in the presence of several sag rod lines and with the largest available section. The choice of conventional steel deck instead of a standing seam roof is slightly conservative for a sloped roof when the tables in the present catalog are used. 12

12 LATERAL STABILITY OF PURLINS LOADS ON DISCRETE BRACING LINES METRIC TABLE 1 Z SECTIONS ON A 2/12 ROOF PITCH AND DISCRETE BRACING LOAD COEFFICIENTS (Pn) Span 3,000 mm 3,000 mm 4,500 mm 4,500 mm 6,000 mm 6,000 mm 6,000 mm 7,000 mm 7,000 mm Number of discrete bracing Material 152Z76-144M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-144M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Pn = load coefficient per section for 1 kn/m of factored vertical load per discrete bracing line. Axial load in a bracing line (kn) = number of sections per slope x the Pn value indicated in the table x factored vertical load in kn/m. (See Step 5 of the example on page 12 for more information.) 13

13 LATERAL STABILITY OF PURLINS TABLE 2 Z SECTIONS ON A 4/12 ROOF PITCH AND DISCRETE BRACING LOAD COEFFICIENTS (Pn) Span 3,000 mm 3,000 mm 4,500 mm 4,500 mm 6,000 mm 6,000 mm 6,000 mm 7,000 mm 7,000 mm Number of discrete bracing Material 152Z76-144M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-144M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Z76-181M Z76-218M Z76-254M Z76-290M Z76-326M Pn = load coefficient per section for 1 kn/m of factored vertical load per discrete bracing line. Axial load in a bracing line (kn) = number of sections per slope x the Pn value indicated in the table x factored vertical load in kn/m. (See Step 5 of the example on page 12 for more information.) 14

14 LATERAL STABILITY OF PURLINS TABLE 3 C SECTIONS ON A 2/12 ROOF PITCH AND DISCRETE BRACING LOAD COEFFICIENTS (Pn) Span 3,000 mm 3,000 mm 4,500 mm 4,500 mm 6,000 mm 6,000 mm 6,000 mm 7,000 mm 7,000 mm Number of discrete bracing Material 152S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-144M S89-181M S89-218M S89-254M S89-290M S89-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-218M S89-254M S89-290M S89-326M Pn = load coefficient per section for 1 kn/m of factored vertical load per discrete bracing line. Axial load in a bracing line (kn) = number of sections per slope x the Pn value indicated in the table x factored vertical load in kn/m. (See Step 5 of the example on page 12 for more information.) 15

15 LATERAL STABILITY OF PURLINS TABLE 4 C SECTIONS ON A 4/12 ROOF PITCH AND DISCRETE BRACING LOAD COEFFICIENTS (Pn) Span 3,000 mm 3,000 mm 4,500 mm 4,500 mm 6,000 mm 6,000 mm 6,000 mm 7,000 mm 7,000 mm Number of discrete bracing Material 152S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-144M S89-181M S89-218M S89-254M S89-290M S89-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-218M S89-254M SS89-290M S89-326M Pn = load coefficient per section for 1 kn/m of factored vertical load per discrete bracing line. Axial load in a bracing line (kn) = number of sections per slope x the Pn value indicated in the table x factored vertical load in kn/m. (See Step 5 of the example on page 12 for more information.) 16

16 C SECTIONS NEW NOMENCLATURE New nomenclature International system Imperial system Former nomenclature SI Imperial d b h t d b h t SI Imperial 152S70-144M 600S C152x4.3 C6x S70-181M 600S C152x5.2 C6x S70-218M 600S C152x6.0 C6x S70-254M 600S C152x7.0 C6x S70-290M 600S C152x8.3 C6x S70-326M 600S C152x8.9 C6x S70-144M 800S C203x5.1 C8x S70-181M 800S C203x6.0 C8x S70-218M 800S C203x7.0 C8x S70-254M 800S C203x8.0 C8x S70-290M 800S C203x9.1 C8x S70-326M 800S C203x10.6 C8x S89-181M 900S C229x6.8 C9x S89-218M 900S C229x8.0 C9x S89-254M 900S C229x9.4 C9x S89-290M 900S C229x10.7 C9x S89-326M 900S C229x11.9 C9x S89-144M 1000S C254x5.7 C10x S89-181M 1000S C254x7.0 C10x S89-218M 1000S C254x8.6 C10x S89-254M 1000S C254x10.0 C10x S89-290M 1000S C254x11.3 C10x S89-326M 1000S C254x12.7 C10x S89-181M 1200S C305x8.0 C12x S89-218M 1200S C305x9.5 C12x S89-254M 1200S C305x11.0 C12x S89-290M 1200S C305x12.5 C12x S89-326M 1200S C305x14.0 C12x S89-218M 1400S C356x10.4 C14x S89-254M 1400S C356x12.1 C14x S89-290M 1400S C356x13.8 C14x S89-326M 1400S C356x15.5 C14x10.4 NEW NOMENCLATURE SI EXAMPLE: 152S70-144M With 152 = depth of section (mm) S = C section 70 = flange width (mm) 144 = minimum steel thickness, i.e. 95% of the design thickness (10-2 mm) M = International system nomenclature (metric) IMPERIAL EXAMPLE: 600S With 600 = depth of section (10-2 in.) S = C section 275 = flange width (10-2 in.) 57 = minimum steel thickness, i.e. 95% of the design thickness (10-3 in.) FORMER NOMENCLATURE SI EXAMPLE: C152x4.3 With C = C section 152 = depth of section (mm) 4.3 = nominal linear weight (kg/m) IMPERIAL EXAMPLE: C6x2.9 With C = C section 6 = depth of section (in.) 2.9 = nominal linear weight (lb./ft.) 17

17 C SECTIONS PROPERTIES METRIC Y b h t/2 t X d S.C. C.G. X e x Y EXAMPLE: 152S70-144M With 152 = depth of section (mm) S = C section 70 = flange width (mm) 144 = minimum steel thickness, i.e. 95% of the design thickness (10-2 mm) M = International system nomenclature (metric) SECTIONS DIMENSIONS No. New Former nomenclature nomenclature d b h t 1 152S70-144M C152x S70-181M C152x S70-218M C152x S70-254M C152x S70-290M C152x S70-326M C152x S70-144M C203x S70-181M C203x S70-218M C203x S70-254M C203x S70-290M C203x S70-326M C203x S89-181M C229x S89-218M C229x S89-254M C229x S89-290M C229x S89-326M C229x S89-144M C254x S89-181M C254x S89-218M C254x S89-254M C254x S89-290M C254x S89-326M C254x S89-181M C305x S89-218M C305x S89-254M C305x S89-290M C305x S89-326M C305x S89-218M C356x S89-254M C356x S89-290M C356x S89-326M C356x (Table continued on page 19) 18

18 C SECTIONS Regular units of measurement are shown in parentheses. d = depth of section (mm) b = flange width (mm) h = length of lip (mm) t = steel thickness (mm) A = gross area of section (mm 2 ) C.G. = center of gravity S.C. = shear center I x = moment of inertia about axis X-X: maximum compressive stress = 0.6 F y (10 6 mm 4 ) S x eff = elastic section modulus about axis X-X: maximum compressive stress = 0.9 F y (10 3 mm 3 ) r x = radius of gyration about axis X-X (mm) I y = moment of inertia about axis Y-Y (10 6 mm 4 ) S y eff = elastic section modulus about axis Y-Y: maximum compressive stress = 0.9 F y (10 3 mm 3 ) r y = radius of gyration about axis Y-Y (mm) x = distance from center of web to center of gravity (mm) e = distance from center of web to shear center (mm) PROPERTIES SECTIONS I x S x eff r x I y S y eff r y x e A New nomenclature (imperial) S S S S S , S S S S , S , S , S S , S , S , S , S S S , S , S , S , S S , S , S , S , S , S , S , S , S

19 C SECTIONS SELECTION TABLE FOR FACTORED LOADS METRIC F y = specified minimum yield strength = 345 MPa M re = factored moment resistance (kn m) M u = factored moment resistance considering lateral buckling (kn m) L u = maximum laterally unsupported length for which a member can develop Mr (mm) V r = factored shear resistance (kn) P r = factored bearing resistance (kn) for a 100 mm bearing The tables on the following pages list M r, the factored bending moment resistance for Canam C sections, as well as L u, the maximum laterally unsupported length without lateral support in torsion and buckling for which this moment is valid. The maximum shear resistance, V r, is listed for each section. M u is the maximum factored bending moment that the section can resist at the specified laterally unsupported length (L u ). The maximum factored bearing resistance, P r, is given for a bearing length of 100 mm. SECTIONS No. New Former nomenclature nomenclature V r P r L u M re 1 152S70-144M C152x , S70-181M C152x , S70-218M C152x , S70-254M C152x , S70-290M C152x , S70-326M C152x , S70-144M C203x , S70-181M C203x , S70-218M C203x , S70-254M C203x , S70-290M C203x , S70-326M C203x , S89-181M C229x , S89-218M C229x , S89-254M C229x , S89-290M C229x , S89-326M C229x , S89-144M C254x , S89-181M C254x , S89-218M C254x , S89-254M C254x , S89-290M C254x , S89-326M C254x , S89-181M C305x , S89-218M C305x , S89-254M C305x , S89-290M C305x , S89-326M C305x , S89-218M C356x , S89-254M C356x , S89-290M C356x , S89-326M C356x , (Table continued on page 21) 20

20 C SECTIONS Example: Single span of 7,500 mm, spacing of 1,600 mm: external pressure + internal suction ( ) = 0.70 kpa external suction + internal pressure ( ) = 0.60 kpa Use two X bracings to prevent the section from buckling and torsion at a third of the span and hold the girt line straight ; metal siding on outside flange attached every 310 mm c/c. Pressure w f = 1.4 x 0.70 kpa x 1.6 m = 1.57 kn/m Suction w f = 1.4 x 0.60 kpa x 1.6 m = 1.34 kn/m + M f = 1.57 kn/m x (7.5 m) 2 / 8 = kn m - M f = 1.34 kn/m x (7.5 m) 2 / 8 = 9.45 kn m V f = 1.57 kn/m x 7.5 m / 2 = 5.89 kn I min (deflection < span / 180) = 180 x 5 x 1.12 kn/m x (7,500 mm) x 200,000 MPa = 5.5 x 10 6 mm 4 The Properties table lists many profiles with a value of I x greater than I min : 203S70-254M I x = 6.2 x 10 6 mm 4 229S89-181M I x = 6.9 x 10 6 mm 4 254S89-144M I x = 7.1 x 10 6 mm 4 The table also indicates that the strength of these three profiles: + M u with 2,500 mm of unsupported compression flange > M f - M u with 2,500 mm of unsupported compression flange > M f The X bracings must be connected to the section according to standard S as described in the section entitled Lateral Stability of Purlins (see pages 7-12). V r > V f P r > V f, except for 254S89-144M. If this section is selected, the connection to the support must be made by bolting the web to prevent web crippling over the bearing. The final selection will be determined according to the other bays of the building and the desired economy in steel or space. M u Sections Unsupported length New nomenclature 1,500 1,800 2,100 2,400 2,700 3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500 7,000 7,500 8,000 (imperial) S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S

21 C SECTIONS PROPERTIES IMPERIAL Y b h t/2 t X d S.C. C.G. X e x Y EXAMPLE: 600S With 600 = depth of section (10-2 in.) S = C section 275 = flange width (10-2 in.) 57 = minimum steel thickness, i.e. 95% of the design thickness (10-3 in.) SECTIONS DIMENSIONS No. New Former nomenclature nomenclature d b h t 1 600S C6x S C6x S C6x S C6x S C6x S C6x S C8x S C8x S C8x S C8x S C8x S C8x S C9x S C9x S C9x S C9x S C9x S C10x S C10x S C10x S C10x S C10x S C10x S C12x S C12x S C12x S C12x S C12x S C14x S C14x S C14x S C14x (Table continued on page 23) 22

22 C SECTIONS Regular units of measurement are shown in parentheses. d = depth of section (in.) b = flange width (in.) h = length of lip (in.) t = steel thickness (in.) A = gross area of section (in. 2 ) C.G. = center of gravity S.C. = shear center I x = moment of inertia about axis X-X: maximum compressive stress = 0.6 F y (in. 4 ) S x eff = elastic section modulus about axis X-X: maximum compressive stress = 0.9 F y (in. 3 ) r x = radius of gyration about axis X-X (in.) I y = moment of inertia about axis Y-Y (in. 4 ) S y eff = elastic section modulus about axis Y-Y: maximum compressive stress = 0.9 F y (in. 3 ) r y = radius of gyration about axis Y-Y (in.) x = distance from center of web to center of gravity (in.) e = distance from center of web to shear center (in.) PROPERTIES SECTIONS I x S x eff r x I y S y eff r y x e A New nomenclature (metric) S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S70-144M S70-181M S70-218M S70-254M S70-290M S70-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-144M S89-181M S89-218M S89-254M S89-290M S89-326M S89-181M S89-218M S89-254M S89-290M S89-326M S89-218M S89-254M S89-290M S89-326M 23

23 C SECTIONS SELECTION TABLE FOR FACTORED LOADS IMPERIAL F y = specified minimum yield strength = 345 ksi M re = factored moment resistance (kip ft.) M u = factored moment resistance considering lateral buckling (kip ft.) L u = maximum laterally unsupported length for which a member can develop Mr (ft.) V r = factored shear resistance (kip) P r = factored bearing resistance (kip) for a 4 inch bearing The tables on the following pages list M r, the factored bending moment resistance for Canam C sections, as well as L u, the maximum laterally unsupported length without lateral support in torsion and buckling for which this moment is valid. The maximum shear resistance, V r, is listed for each section. M u is the maximum factored bending moment that the section can resist at the specified laterally unsupported length (L u ). The maximum factored bearing resistance, P r, is given for a bearing length of 4 inches. SECTIONS No. New Former nomenclature nomenclature V r P r L u M re 1 600S C6x S C6x S C6x S C6x S C6x S C6x S C8x S C8x S C8x S C8x S C8x S C8x S C9x S C9x S C9x S C9x S C9x S C10x S C10x S C10x S C10x S C10x S C10x S C12x S C12x S C12x S C12x S C12x S C14x S C14x S C14x S C14x (Table continued on page 25) 24