EWPAA Structural Plywood and LVL Design Manual - Engineered ...

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13.16 Design of Type 2 Bolted ConnectionsEquation 13.15 gives the design capacity (ΦN j ) for a type 2 joint containing (n) bolts which are loaded indirect tension.For the strength limit state to be satisfied:where ΦNj is the lesser of:ΦN jΦN j≥ N* (13.15)= n(Φ Ntb ) (13.16)OR where crushing under the washer results in a limit on strength :and:ΦN j = Φ.k 1 .k 7 .nf”pj.Aw (13.17)N* = design action due to factored tensile loadsN = number of bolts in the jointΦN tb = design tensile capacity of bolts (Table 4.12)Φ = capacity factork 1 = duration of load factorK7= length of bearing factor of washer (Table 4.12)f’ pjA= characteristic bearing strength of timber in joints= effective area of washer for bearing.(Table C6)wMoment Resisting and Eccentric Bolted JointsAS 17201.1-1997 only real concern regarding moment joints for bolted connections is thatassociated with joint eccentricity. No guidance is given concerning the design of boltedmoment joints required to sustain large applied moments as can occur, for example, inportal frame knee joints.The design of bolted moment joints incorporating rigid steel side plates can be effected byapplication of the classical mechanics formula τ =Tρ/J. However, the objective of this Manualis to provide guidance to designers using plywood and LVL and moment joints with thesematerials are best done using nails as the connector as described in Chapter 10.Eccentric joints arise when the centre lines of action of their member forces, for example,those of a truss joint do not intersect at a common point as shown in FIGURE 13.10. Thisindiscretion can cause fairly high shear and moments to develop and tensile stressesperpendicular to the grain may also be high.FIGURE 13.10: Eccentric joint207
Because of the lines of actions of the (3) forces are not concurrent the connection is nowtreated as two separate connections. The bending shear is then determined for eachjoint through the application of the classic bending shear equation:f s = VQ / ItThis results in the A sj term containing the 2/3rds of shear area, b x d s .To accommodate this type of situation AS 1720.1-1997 recommends the secondary stressesdue to bending moment be checked to ensure no member or fastener is overstressed.Further, the design capacity in transverse shear at an eccentric joint (ΦV sj ) satisfiesEquations 13.18 and 13.19.where:and:ΦV sjΦV sj≥ V* sj= Φk 1 k 4 k 6 f” sj A sjV* = design action on the joint due to the factoredsjapplied loads, i.e. transverse shear at jointΦ = capacity factork 1 = duration of load factork4= partial seasoning factork6f' sj= temperature effects factor=characteristic strength in shear at joint detailsappropriate to species strength groupA sj = transverse shear plane area at joint;= 2.b.ds/3 where b is thickness of the member. SeeFIGURE 13.10. for d s .(13.18)(13.19)WashersAS 1720.1-1997 states all timber-to-timber bolted structural joints shall be fitted with awasher each end.The function of the washers in a bolted structural connection is two-fold:• having a larger diameter than the head and nut of the bolt, they distribute an axialforce in the bolt over a larger area;• provided the bolt is kept tight to combat shrinkage the washer can minimise waterpenetrating into the bolt hole. This reduces the possibility of rust of the bolt androtting of the timber.Serviceability Requirements for Type 1 Bolted Joints (Cl.C3.3)AS 1720.1-1997 provides relationships to determine connection deformations of solid timberjoints fabricated with bolts as the connectors. The equations provide estimates ofdisplacements if no test data for the connection response is available.The equations give reasonable results for the deflection of Type 1 joints under serviceabilityloadings. Joints become less stiff after a number of load cycles resulting in thedeformation predictions become less accurate.Equations 13.20 and 13.21 give the displacement ∆, taking into account grain direction.Δ = Δi+jj1433Q *Qkfor loads parallel to grain (13.20)208
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Structural Plywood & LVL Design Man
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Table of Contents1 Plywood & LVL -
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11 Plywood Stressed Skin Panels ...
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Table of FiguresFIGURE 4.1: Plywood
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Part OneProduct Production & Proper
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PeelingAfter conditioning, the logs
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Sanding, Trimming and BrandingAfter
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through to applications where aesth
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2.7 Identification CodeThe plywood
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2.10 Non Structural PlywoodsInterio
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3.5 Veneer QualityVeneer quality us
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the hygroscopic movement of structu
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effective an insulator as the wood
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5 Structural Plywood - Design Princ
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12 - 13 40015 - 19 45020 - 25 52026
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TABLE 5.3: Standard Structural Plyw
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TABLE 5.5: Indicative Stiffness Val
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Strength Limit StateStrength LimitS
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Application of Structural memberAll
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FIGURE 5.5 shows an I-beam defining
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j 2- Duration of Load Factor for Cr
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Using the theory of parallel axes a
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6 Structural LVL - Design Principle
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I (neutral axis(NA)-stiffness= (bd
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Serviceability Limit State:Calculat
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Strength Limit State:Strength Limit
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Equilibrium Moisture Content (EMC)P
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(c) For shear k 11 = 1.0(d) For com
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Chapter 6 AppendixSlenderness Co-Ef
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FIGURE A6.3: Continuous restraint a
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Stability factor.The stability fact
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7.4 Structural Plywood Flooring - D
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5. Critical Load Action EffectsLoad
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5. Serviceability limit state - Des
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7.10 Structural Plywood Residential
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Because of the obvious difficulty a
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1.2 m roof load width)0.25 kPa x 1.
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Concentrated Imposed Load (Q)M max
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5. Serviceability Limit Stateand [A
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8 Structural Plywood Webbed Box Bea
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AdhesivesBeams relying only on an a
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5. Check Beam Stiffness:Check beam
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1. Initial beam trial size:(a)(b)Fr
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Required nail spacing s = øN j / q
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Figure 8.5 shows a discontinuous pl
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A8Chapter 8 AppendixBending / Compr
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where:A= h3.5 3D .1032 N. mJ12.440.
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FIGURE A8.2: Guide for Selecting In
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Table A8.6: Unit-Load Deflection Sp
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9 Structural Plywood Diaphragms & S
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FIGURE 9.3 shows a plywood panel na
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The following are the design steps
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Wind force, w on diaphragm w = 1.86
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Converted to Limit States CapacityC
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4. Chord Size and SplicesThe chords
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Load/Nail (N)Nail Deformation (mm)2
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• The horizontal force is 1.9 x 2
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= 5 kN/m v oR = 15/5 = 3 kN/m107
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ELEVATIONFIGURE 9.12: Shows shear f
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As previously mentioned the shearwa
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Assuming the applied racking load t
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In this instance let the two panels
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A9 CHAPTER 9 APPENDIXPlate 1Plate 2
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Plate 7Plate 8Plate 9119
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REFERENCES CITED:1. Timber Shearwal
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“nailability” by increasing res
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(a) (b) (c)FIGURE 10.3: Actual and
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Re-arranging the torsion equation r
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The polar moment of area (I p ) of
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Design Example - Plywood Gusseted P
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• assuming width of lines paralle
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hence:where:ΦMj⎡ Ip⎤= (0.8 x1.
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A10 Chapter 10 AppendixPhotographs
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MOMENT JOINTSPlate 7Plate 8Plate 9(
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REFERENCES CITED:1. Investigation o
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11.2 MaterialsPlywoodPlywood used i
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FIGURE 11.3: Effective widths of pl
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Transformed SectionSince the plywoo
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FIGURE 11.5: Bending stresses in st
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FIGURE 11.6: Stressed skin panel tr
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Flexural Deflection Long Term Servi
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Compression SpliceUsing 17mm F11 st
Page 166 and 167: REFERENCES CITED:1. Design & Fabric
Page 168 and 169: 12 Exotic Structural Forms12.1 Intr
Page 170 and 171: displacement between diaphragms eac
Page 172 and 173: The section modulus (Z) is:ZZ=Iy1=1
Page 174 and 175: FIGURE 12.9: A parabolic arch (not
Page 176 and 177: F AFFFASS= (374.4 + 166.4)kN= 540.8
Page 178 and 179: 12.11 Hypar Design - GeometryTo dev
Page 180 and 181: FIGURE 12.16: Reactive force compon
Page 182 and 183: 12.14 Methodology - Principal Membr
Page 184 and 185: Many braced dome geometries exist b
Page 186 and 187: θasphere= is the angle subtended b
Page 188 and 189: AndNNNxyxyP=L21P=L12P=L33L2P3⎤+
Page 190 and 191: • whether or not to force the ply
Page 192 and 193: A12Chapter 12 AppendixEXAMPLES OF E
Page 194 and 195: EXOTIC STRUCTURAL FORMS DESIGN AIDS
Page 196 and 197: Type 1 joints referred to in AS 172
Page 198 and 199: FIGURE 13.3: Two and Three member T
Page 200 and 201: SECTION 4 : AS 1720.1-1997 : Clause
Page 202 and 203: connection load carrying capacity c
Page 204 and 205: 13.5 Design of Type 1 Nailed Connec
Page 206 and 207: The following unfactored loads are
Page 208 and 209: nnaa=nnr42=5= 9 rowsThe assumed val
Page 210 and 211: 13.11 Design of Type 2 Screwed Conn
Page 212 and 213: The reasons k 13 and k 14 are not c
Page 214 and 215: Type of JointSeasoned TimberUnseaso
Page 218 and 219: where:Δ = Δi +h33j14xh35Q *Qkpfor
Page 220 and 221: The exploded view in Figure 13.11 s
Page 222 and 223: FIGURE 13.12: Edge, end and bolt sp
Page 224 and 225: 13.21 Design of Type 2 Coach Screwe
Page 226 and 227: REFERENCES CITED:1. AS 1720.1-1997,
Page 228 and 229: Plate 3Plate 4219
Page 230 and 231: Plate 7Plate 8221
Page 232 and 233: 14 Noise Control14.1 IntroductionTh
Page 234 and 235: The absorption process of a single
Page 236 and 237: When it is required to add more tha
Page 238 and 239: FIGURE 14.5: Types of cavity wallsT
Page 240 and 241: 15 Condensation & Thermal Transmiss
Page 242 and 243: 15.4 Thermal TransmissionThermal tr
Page 244 and 245: 15.5 Thermal Transmission - Design
Page 246 and 247: REFERENCES CITED:1. Condensation, C
Page 248 and 249: The early fire hazard test indices
Page 250 and 251: ISO 9705 AND AS/NZS 3837These tests
Page 252 and 253: General InformationDesign of struct
Page 254 and 255: SpeciesAsh, Alpine - Eucalyptus del
Page 256 and 257: Results of recent tests organised b
Page 258 and 259: FlooringConstructionLVL(Substrates
Page 260 and 261: as expressed in the BCA.Species Ave
Page 262 and 263: ClosurePlywood Thickness for:Dougla
Page 264 and 265: Borers are rarely a problem with st
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HazardClassH1Exposure Specific serv
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17.3 Durability and Finishing Appli
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EWPAA MembersPlywood and Laminated
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