Chapter 15 Design Data

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hapter 5Design data

IntroductionThis chapter brings together useful information available elsewhere ,but n a more convenient form. Much of this information hasbeen extracted directly from the Timber Structures Standard , ZS3603 : 1993 including amendments I to 4 . This chapter provides handyreferences to th e k factors and stre tables and infom1ation on thederi va tion of design trengths . This document s intended to assistdesigners u s ing NZS 3603. lt s not an alternative or substitute for theStandard, which should be consulted for more complete information .

Design methodsTimber design n accordance with ZS 3603 i based on the limitsta tes method of design and refers to the Structural Design ActionsStandard , AS ZS 1170. The designer should be familiar with therequirements of both NZS 360 and AS/NZS 1170. When a s tructure ,or part of it , fails to fulfill ba sic functions , it s said to have reached a

limit state . Two limit states are identified , namely

the serviceabi lity limit stat e andthe ultimate limit sta te

The se rv iceability limit state (SLS) deals with deformation anddeflection limits which affect the appearance or function of abuilding . The ultimate limit state relates to the strength and stabilityof all or part of a building. The ultimate limit tate ULS) is deemedto be satisfied if the structura l timber members are proportioned sothat their design strengths are not less than the actions produced by

the facto red design loads from AS/NZS 1170 .

TerminologyThe terminology used n this Guide follows the definitions given byPaulay and Priestly • Vertical actions on a structure from gravity andself-weight are called loads . All other external actions on a structure ,including those from wind and earthquake are called forces. Theresulting internal effects such as axial force , shear force and bendingmoment are called int ernal actions .

Design actionsThe design actions and their combinations are prescribed n theStructural Design Actions Standard AS ZS 1170 , for both ultimatestrength and serviceability limit states design.

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For the ultimate limit state, the main load combinations in AS NZS1170 .0 are given in Table 15 . 1:

Table 15 .1 Combinations of actions.

Load Comb inat ion

Dead load only (permanent) 1.35G

Dead and live load (medium duration) 1.2G & 1. a

Gravity plus downward w ind 1.2G & 'ilea & W

Gavity plus upward wind 0 .9G & W u

Earthquake combination G liJp

Snow combination 1.2G & 'Ilea & S

G is permanent load (dead load )a is imposed load (live load)W is wind forceE. is seismic force , ands. is snow load

The jJ factors use d to combine these action are given in Table15 . 1. For the serv iceability limit tate , load combinations and typicalcriteria (from ZS 1170.0) are given in Table 16.1.

Table 15 2 iJ factors used fo r combinations of actions.

Imposed act io nShort -term Long -term Comb in ti o nf cto r ( IJ. ) facto r (IJ,) fac to r ( IJJ

Distributed imposed actions , Q

Floors for residential , 0 .7 0.4 0.4domestic , office or retail use .

Floors for storage 1.0 0.6 0 .6

Roofs 0.7 0 .0 0 .0Concentrated imposed actions , QResidential & domestic 1 .0 0.4 0.4floorsOther floors 0 .7 0 .6 0 .6Roofs 1 .0 0.0 0 .0

Design strengthDe s ign strengths are defined as the product of the relevants trength reduction factor, characteristic stress, sec tion propert yand modification factors for the condition expected in service.

Characteristic s tresses (as tabulated on the following pages ) are thosestresses which can safely be su tained by a particular grade of timberat a specified moisture content under briefly applied load s. In ZS3603, the st ren gt h reduction factor


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Tabl e 15 4 Character istic stresses or visually graded t imbe r, radiata pine and Douglas ir .

1. Moisture c ondi ti on - Dry (m /c = 16 )Grade Bending Compression Tension

parallel

fb fc r(MPa) (MP a) (MPa)

VSG10 20 .0 20 .0 8 .0

VSG8 14 .0 18 .0 6 .0No . 1 Framing 10 .0 15 .0 4 .0

2. Moistur e cond itio Green (m/c = 25 )G 11.7 12 .0 4.0No . Framing 7.5 11.0 3 .0

NOTES -

Shear inbeams

'·MPa)

2.42.4

Compressionperpendicular

fp(MPa)

8.9

8.98.9

5.35 .3

Modulus ofelasticity

(GPa)10.0

8.06.0

6 .54 .8

Lower boundmodulus of elasticity

b

(GPa)6.7

5.44.0

4.43.2

• Shear strength for dry Radiata pine shall be taken as f5

= 3 .8 MPa . Shear strength for dry Douglas fir shall be taken as f5

= 3 .0 MPa .Modulus of rigidity shall be taken as G = E/15.No. 1 Framing grade is not verified and is not subject to in-mill monitoring of strength and stiffness properties. No . 1 Framing is visuallygraded to the requirements of NZS 3631.VSG grades shall be verified as required by NZ 3622 .

VSG10 and VSG8 for green use are visual grades that have been verified in the dry condition .GB is a visual grade that has been verified in the green condition.

The green condition stresses and modulii values shall be used where the grades shown are used in service conditions where the moisturecond ition may be 25 or over. The durabil ity requirements of NZS 3602:2003 must also be met.

Tab le 15 5 Characteristic stresses for dry mechanically graded timber, radiata pine and Douglas fir.

Grade

MSG15MSG12

MSG10MSG8

MSG6

NOTES :

Bending

fb(MPa)

41.028.0

20.014.010.0

Compression Tensionparallel

fc r(MPa) (MPa)

35.0 23 .025 .0 14 .0

20.0 8 .018.0 6 .0

15.0 4 .0

Shear in Compression Modulus of Lower boundbeams perpendicular elasticity modulus of

elasticityf fp b

(MPa) (MPa) (GPa) (GPa)

8 .9 15.2 11.58 .9 12.0 9 .0

8 .9 10.0 7.58.9 8 .0 5.48.9 6 .0 4.0

• Shear strength for dry radiata pine shall be taken as r = 3.8 MPa. Shear strength for dry Douglas fir shall be taken as f5= 3.0 M P a .

Modulus of rigidity shall be taken as G = E/15 .MSG grades shall be verified as required by NZS 3622.

Ta ble 15 6 Characteristic stresses for na turally round softwood timbers in the green condition .

Ou ter zone density Property

Category Minimum Bending Compression Tension Shear Compression Modulus of(kg/m 3 parallel perpendicular elasticity

fb fc r '· fp(MPa) (MPa) MP a) MP a) (MPa) (GPa)High 450 52 25 31 3.5 9.0 1.1

Normal 350 38 21 23 3.1 8.8 8 .7NOTE:

The outer zone density is the basic density (oven dry weight/volume in green condition) in the outer 20 of the radius.

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Table 15 .7 Characteristic stresses for dry structural plywood.

Stress Bending Tension Panel Rolling Compress ion Bearing Modulus Modulusgrade shear shear in the plane o normal to the o o rigidity

the sheet plane o the elasticitysheet

fb f · f fc fp G(MP a) (MPa) (MPa) (MPa) (MPa) (MPa) (GPa) (MPa)F17 50 30 6 .8 2.4 40 20 14 .0 700F14 40 25 6.1 2 .2 30 15 12 .0 625F11 35 20 5 .3 1.9 25 12 10.5 525F8* 25 15 4 .7 1 .7 20 9 .7 9.1 455F7 20 12 4 .2 1.5 15 7 .7 7.9 345

*F8 is the most commonly available stress grade for plywood in New Zealand . F11 and other stress grades have limited availability .For extremely high strength hardwood plywood grades and their characteristic values , refer to AS/NZS2269.E is the short duration average modulus o elast icityG is the short duration average modulus o rigidity

Table 15 8 Characteristic stresses for dry LVL laminated veneer lumber) .

Product Bending Compression Tension Shear inparallel parallel beams

fb fc f ·MPa) (MPa) (MPa) (MPa)CHH hySPAN 48 45 33 5 .3

CHH Hy90 35 28 19 5.3

Nelson Pine LVL10 48 45 30 6.0

Table 15 9 Characteristic stresses for dry L grades of glulam.

Grade Bending Compression Tension Shear inparallel beamsfb fc f

·MPa) (MPa) (MPa) (MPa)GL18 50 50 25 5 .0GL17 42 35 21 3 .7GL13 33 33 16 3 .7GL12 25 29 12.5 3 .7GL 10 22 26 11 3 .7GL8 19 24 10 3 .7

GL grades greater than GL 10 can be difficult to obtain in radiata pine .

GL grades greater than GL 12 can be difficult to obtain in Douglas fir .

Equivalence to other standardsDesigners occasionally have to design to other standards such asEurocode 5 or the Chinese code GBJ-5. Usually the only problem isto know bow ew Zealand grades equate to the grades cited in thosestandards. The approximate equiva lence between the MSG grades andthose listed in EN338 and GB50005 is given in Table 15 . 10

Table 15 10 Equivalence between NZ , European and Chinesestructural timber grades.

Country Reference Grade

NZ NZS3603 MSG6 MSG8 MSG10 MSG12 MSG15Europe EN338 C16 C22 C27 C40China GB50005 M10 M22 M30 M40

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Compression Modulus operpendicular elasticity

fp

(MPa) (GPa)

12 13 .2

10 9 .0

12 10 .7

Modulus o Modulus ofelasticity rigidity

G(GPa) (GPa)18500 123016700 110013300 90011500 77010000 6708000 530

Design methodsDeflection

Initial elastic deflections can be calculat edusing standard engineering analysis. NS Z3603 specifies that a ll owance for long termdeflection be made by multiplying thecalculated elastic deflection for each part ofthe load by the duration o f load factor fordeflection k 2 corresponding to that part of the

load as given in Table 15 11

The reason for the lower creep in glulam isthat the members are generally much l argerthan sawn timber on which the creep factorsare based . The greater size means that themember cannot respond to fluctuation s in


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atmo sp heric humidity and so experiencethe changes in moisture content which arethe princi pal cause of creep deformation s in

timber

t ren gth

In genera l, the design strength is given byS* S R

where S* i the design action from thefactore d load combinations and R is thedes ign stre ngth where

R is the nominal strength of the member ,and

j> is the strength reduction factor

Ln ben ding, for examp le as shown in hapter

16, the design equation for bending strengthis:

where

M* is the design level of bending moment ,resu lting from the factored applied loads

M is the nominal bending strength , givenby:

M = kfb

where

Ji = characteristic stress in bendingZ = sect ion modulusk = product of all the modification factors

ap propriate to the service conditions

Some of the commonly used k factors areshow n below .

Desig ners should refer to ZS 3603 forconsi deration of other items including:

Str ength of notched beamsRa dial stresses in tapered membersDe sign for combined stresses

Durat ion of load factor for strengthk l

The du ration of load factor for strengthrecog nises that timber has a greater strengthund er briefly applied loads than under longtenn loads. For design k is chosen accordingto the duration of the shortest component ofthe to tal load .

Ta ble 15.12 gives f actor k and examples oftypes of loads appropriate to different loadduratio ns . All combinations of load s shou ld

be checked using the value of k pertaining to the load of shortestduration in each combination.

Table 15 .11 Durat ion of load facto r k for deflect io n.

k2

Duration of load Moisture content For bending ,

at time of compression orloading shear

12 months or more 25 or more 3.0

12 months or more 18 or less 2.0*

2 weeks or less Any 1 0

*For glue laminated timber use 1.5

Table 15.12 Duration of load factor k for strength.

For

tension

1.5

1.0

1.0

Durat ion of load Type of load k 1Permanent Dead loads and live loads that are essentially 0 .6

permanent such as stores (including water tanksand the like) , library stacks , files , fixed plant ,soil.

Medium Snow loads , live loads , crowd loads , concrete 0 .8formwork , vehicle , pedestrian , and livestockloads. Erection loads and maintenance loads.

Brief Wind , earthquake , impact and pile driving loads . 1.0

Bearing area factor k 3The bearing area factor adjust the bearing strength for the area of

timber loaded in compression perpendicular to grain. This factorwill apply for the end supports of beams or end bearing of columns.For values of k 3 see Figures 15 . 1 and 15.2. The value of k 3 may becalculated from Is = I +1 2e

Figure 15.1 Length of bearing surface from NZS 3603 .

Length of bearingsurface for the

design of the joist

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2 0

1.8

1.6

1 .2

1 0

1 \\

\.

[ -.1

r r

50 100 150

. Length of bearing surface mm)Figure 15 2 Bearing area f c t o r ~ ·

Parallel support factor

200

The parallel support factor k_ can be used when two or more elementsare connected o that they are constrained to the same deformation , asshown conceptually in Figure 15.3. Th is apparent increase in strengthresults from the natural variability o f strength and stiffness in timbermembers o f a given size and grade. If a single member is carryingthe load, the strength is based on the 5th percentile (or cha racteristic)strength o f the population. If several members share the load , a higherdesign strength can be used because o f the probability o f strongermembers being in the system. Factor k 4 a lso recognises that weakertimber is genera lly less stiff, which means that it can shed load tostiffer and stronger pieces. The factor k 4 is tabulated in Table 15 .9 or

may be ca lculated from:

k = ( o.323/Fn)o.667

where n is the number of elements s haring the load.

The parallel support factor k 4 shall not be used for design o f

enginee red wood products with low variability such as LVL becausethe precise properties o f such materials give much less advantagefrom load sharing.

Table 15 13 Parallel support factor k •

Number of elements carrying a common load

2 3 4 5 6 7 8 9 or more

k 1. 1.14 1.2 1.24 1.26 1.28 1.30 1 .31 1.32

Figure 15 3 Parallel support system from NZS 3603}

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Grid system factor k 5The grid system factor is used when a bea msystem supports an overlying set o f memb ersor sheathing having significant bendingstiffness. It app lies to the bending , bearin g,and shear strength o f beams. The factor k5 is

given in Chapter 16.

Stability factor k 8The stability factor considers the effects ofelastic instability on strength o f beams andcolumns

Ca lculation o f the stability factor k8 forcolumns is described in Chapter 17 , and f orbeams in Chapter 16.

Compression at angle to grain

Characteristic stress in compression atangles to grain other than 0 ° or 90 ° may becalcu lated from Hankinson 's formula

or from / 0 = (t _.- J P sin

The first equation (Hankinson s formul a)is used in NZS 3603 . The second equati on(obtained from CIB W 18) is simpler to u seand provides similar answers.

Effect of variations nmoisture contentCharacteristic values for any product shouldbe stated at the correct moisture content f ordesign. In NZS 3603 this is 16% for drytimber and 25 % or more for green timber .Tab le 15.14 provides adjustments to findvalues at any moisture content. Strictlyspeaking these adjustments apply only tosmall defect-free specimens of timber ( sma llc lea rs) and may be invalid in some case sfor structural timber and for panel produ cts.Direct measurements on the product inquestion is always to be preferred.

Glue laminated timb e rStrengthGL grades are perfonnance-based , meani ngthat they are manufactured to have thecharacteristic properties listed in Table 15 .9.GL grades o f glue laminated timber areverified for strength as described in Chap te r 5.


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Tab le 15. 14 Moisture content adjustmentstor stren gth properties

Propertyreduction for

each 1 increase inmoisture content

Mo dulus of rupture(bending strength)

o mp ression parallelto grainCompressionperpendicular to grain

Sh ear strength

Modulus of elasticity

4

5

5

3

1.5

In ad dition to factors k to k5 and k8 describedabo ve for sawn timb er, the following k factorsappl y specifica lly to glue-laminated timber.

u rv ature factor k 23Th e c urvature factor allows for the additionalstress induced in laminations that are bent to atigh t radiu to form curved glulam member s.It i not applied to st raight member s with asli ght cam ber. 's3 i applied to the bendin gstreng th o f curved members and is given by:

wh ere

t k 3 = 1- 2000 -- R

2

= lamination thicknessI

R = radius o f curvature

La mi nation and size factors andk 24

Th e previous lamination factor k6 and theize factor kN have been deleted with the

int ro duction ofGL grades because the GLgrades are performance grades which arepec ifica ll y manufactured to give the assigned

ch ara cteristic stresses.

Sh all ow glulam arches in aircraft hangar roof.

Radial stresses in curved or tapered membersThe strength o f curved g lut am tlexural members needs to be checkedto ensure that fai lur e does not occur due to stresses perpendicularto the grain . If the bending tends to increase the radius of curvature(bending in the opening mode) , the stresses will be in tensionperpendicular to the grain (splitting) . If the bending tends to decreasethe radius o f c urvat ur e (bending in the c losi ng mode) , th e stresses wi ll

be in comp ression perpendicular to the grain (crushing).

The design equation for curved members stressed in the openingmode is:

The design equatio n for cur ved members stressed in the c losing modeis:

where

if is th e trength reduction factork is the duration o f load factor for strengthk

4 is the load sharing factor for number of beam sf is the characteristic hear tre sj is the characteri tic bearing stress perpendicular to the grainpR is the radius of curvature at mid-depth of the sectionb is the breadth of the sectiond is the depth of the section

Design equations for tapered or pitch cambered beams are given in

zs 3603.

lywoodStrengthThe de ign strength o f plywood is obtained in a simi lar manner tothat for awn timber except that account mu st be taken o f the differentcontributions of veneer parallel and perpendicular to the directiono f app li ed stress . This is done by calcu lating section properties asdescribed in AS ZS 2269 or in Appendix F of ZS 3603 . Con ultindividual manufacturers ' literature for ection properties. Sectionproperties for sta nd ard plywood layu ps are given in Chapter 22.

Radiata pine plywood is made with veneer qualities A , 8 , S , C and D,which are defined in AS ZS 2269 and illustrated in Chapter 8

Moisture content

Strength should be modified according to the expected in-servicemoisture content in accordance with Tab le 15.15 .

k 15 face grain orientation factorWhen plywood is stressed at angles to the face grain other than 0°or 9 °, the stre ngth o r stiffness should be modified by the face grainorientation factor k 15 from ZS 3603 .

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Table 15.15 Effect of mois t u re content on plywood s trength fr o mNZS 3603).

u ration of load

Permane nt

Medium

Brief

PolesStrength

Type of load k Dea d load and live loads that are 0 .6essentially permanent such as stores(including: water tanks and the like),

library stacks , files , fixed plant , soilS now loads , live loads , crowd 0 .8loads , concrete formwork, vehicle,pedestrian, and livestock loads .Erection and maintenance loads

Wind , earthquake , impact and pile 1.0driving loads.

The characteristic stresses for poles listed in Table 15.6 are based on

in-grade testing for the major species of softwoods, which are radiatap ine, Corsican pine , Douglas fir and larch . I f in-grade test results arenot available for po les of other species , characteristic stresses can beobtained from small clears data. The characteristic stress is calculated

sk times the mean property o f small c lear specimen test results.p

For poles in bending, k is 0. 71 for modulus o f rupture, and 1.05 forpmodulus of elasticity.

Additional k factors for poles are given below

Peeling or shaving factor k 2The peeling or shaving factor k20 allows for the effect o f bark removal

which usua lly removes the reinforcement provided by the swellingsassoc iated with knots . The effect depends on the amount of swellingremoved. Machine pee ling removes some o f the swelling whileshav ing p roduces a smooth tapered or cylindrical form. k20 is given inTable 15.16.

Steaming factor k 21The steaming factor k21 applies when the preservative treatmentinvolves steaming, such as occurs with the alternating pressure oroscillating pressure methods. k21 is given in Table 15.16.

Dry use factor k 2 2

The dry use factor k considers the increase in wood strength andstiffness with dry conditions and is applied to poles or parts o f polesthat are dry. k

22is given in Table 15.16.

Table 15.16 Pole strength modificat ion factors 2 21 and k 2 z

Factor k Factor k Factor k22Applied to Peeling Shaving Steaming Dry usefb or f 0 .9 0.85 0.85 1.25reor fp 1.00 1.00 0 .9 1.25

· 1.00 1 . 0 .9 1.06E 1.00 0.95 0.95 1 .12

Alternative speciesOccasionally it is necessary to design members in species that arenot listed in ZS3603 , for example to check the adequacy of an

56

historic structure or if a client has sometimber they particularly want to use. Coll ins 2

has addressed this topic for the design o fmembers in houses. There are generall yquestions about strength , stiffness anddurability . The best advice currently avail ab le

is in New Zealand Timb eiJ . Another go odsource is Wood in Australia .

The derivation of design properties from sm allclears data has been described by Bie rS Formost cases it is sufficient to know the a verag emodulus of elasticity (MoE) , since the d esignMoE for structural timbers is approxim atelythe same as that from small clears and th isis usually the critical property . Knowin g thespecies average Mo allows grouping int oYSG /MSG categorie s as shown in Tabl e15.17.

If strength is critical , then the timber w illneed to be inspected to see that knot s a re lessthan 25 o f the cross section which i s themaximum size of knots expected in YSG 8radiata pine . The issue of verification d oesnot arise because that was introduced todeal with problems o f variable properti es inradiata pine .

Derivation ofcharacteristic stre ssesCharacteristic stresses ar e those stre sses tha tcan safely be sustained by a particular s izeand grade o f timber at a specified moi sturecontent under briefly applied loads. Asdefined in ZS 3603 , characteristic stressor strength is an e s timate o f the lower5th-percentile value determined with 75confidence , from tests on a representati ve

sample of full size test specimens. Forstiffness properties , the characteristic value isthe mean value .

Sawn timberThe most reliable characteristic stresse s forstructural timber products are those der ive dfrom testing sawn timber in the sizes an dgrades used in structures (in-grad e tes ting).Because o f the costs involved this has b eendone only on a few sizes ofradiata pin e saw n

timber in bending and tension . The mo retraditional method is to modify strengthproperties obtained from small clear (defec t-free) specimens of timber .

With recent mo ves away from visua l gradi ngto a system of verified strength clas ses


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the need for derivation of characteristicstresses for structural timber has diminished .However, if a producer wants to market nonstandard gra des or species for engineeringuses, it i neces ary to derive characteristicstresses for design , from the results of ingrade test ing as follows:

Te st metho ds and data analysi for in-gradetesting are described in joint Au tralian NewZealand Standard AS ZS 4063. Brieflytated, the 5th-percentile strength of the

pop ulation is estimated with 75% confidenceusing:

R 1- 2 7vR Rk = n 0 .05

wher e

R005 is the 5th-percentile strength value fromin-gra de testing

v is the coefficient of variation of thestreng th va lues

n i the number of pecimens tested(mi nimum 30)

S tion properties andd s ign strengths

ection prop e rtie s and design strength aregiven in Tables 15.19 to 15 .22. Call izes arethe roug h sawn dimensions used to cut wetlogs into board . The boards are treated, kilndr ied, planed and graded to give the sizes inthe beam tables . For timber that is treated andthen planed wet, the s izes are slightly moreto allow for some shrinkage in service, butshrinkage is variable. So for example (in mm)a nomina l I 00 x 50 is 90 x 45 a a kiln driedsize , an d 94 x 4 7 in the wet planer-gaugedize When a 94 x 47 shrinks, it will become

approximately 92 x 46. The tables arecon se rvative on the in-service dry size.

For glu lam, the table izes are the finishedsizes, and for LVL the sizes are the minimumexpected sizes after gluing with tolerances asspecifie d in AS ZS4357 , typica lly -0, +2 inthe th ick ness .

Propert ie s in the tables are shown in Table15 . 18

Glulam portal frame building

Table 15 17 Species grouped by modulus of elasticity

Range of MoE (GPa)5 to 7 7 to 9 9 to to 3

MS G6 MNSG8 MNSG10 MSG12Redwood Corsican pine Larch Mountain BeechLusitanica Macrocarpa Kahikatea Red beechPonderosa Matai Kauri Silver beechPoplar Miro Lawso nsCedar Rimu cypress

Table 15 18 Geometric properties in tables.

Quantity Rectangular Circular sectionsect ion

Dimension b =breadth R =radiusDimension d =depthArea A = b d A= n R2

Section modulus Z = b d 2 /6 Z = R3 / 4Moment of inertia I= b d 3 /12 I= n R4 /4

urther reading

>13

MSG15HardbeechRewarewaTawa

1 Seism ic D esig n of Reinfor ce d Concrete nd Masonry Building sT Paul ay and M.J. . Prie tley. John Wiley Sons , ew York , 1992 .

2 Alternatives to radiata pine for hou se framing to ZS3604 M.J .Collins. NZ T imber Design Jo urnal, Vo l 6, Issue 2, pp 14 24 . 1997

3 New Zealand Timb ers .C. Clifton. GP Publications ,Wellington , ISB 1 86956 1147, 1994 . Reprinted by FRI 2003.

4 Wood in Australia K.R . Bootle . McGraw -Hill Book Co. Sydney ,ISB 0 07 451047 9.1983.

5 Der iva tion o f imber desig n stresses in New Zealand H. Bier .Proceedings of Pacific Timber Eng ineering Conference, pp760-767.1984.

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Table 5 . 9 Sect ion properties of dry t imber MSG and VSG grades

Nominal Nominal Actualbreadth depth breadth

mm mm mm

50

50

50

50

50

50

50

75

75

75

75

75

100

100

100

100

100

100

100

NOTES -

75

100

125

150

200

250

300

100

150

200

250

300

100

150

200

250

300

350

400

45

45

45

45

45

45

45

70

70

70

70

70

90

90

90

90

90

90

90

Strength reduction factor 1 J = 0 .8Modulus of elasticity E = 8 .0 GPa

Actual Area Weight Z ldepth

mm mm 2x10 3 kN/m mm 3 x10 6 mm 4 x10 6 Nmm 2x10 9

70

90

120

140

190

240

290

:m

140

190

240

290

90

140

190

240

290

340

390

3 .15

4 .05

5.40

6 .30

8 .55

10 .80

13 .05

0.30

9 .80

13 .30

16 .80

20.30

8 .10

12 .6

17 .1

21.6

26 .1

30.6

35 .1

0 .016

0 .020

0 .027

0 .032

0 .043

0 .054

0 .065

0 .032

0 .049

0 .067

0.084

0.102

0.041

0.063

0 .086

0.108

0.131

0.153

0 .176

0 .037

0 .061

0.108

0 .147

0.271

0.431

0 .631

0 .095

0 .229

0.421

0 .672

0 .981

0 .122

0 .294

0 .542

0 .864

1.262

1.734

2.282

1.29

2 .73

6.48

10 .3

25.7

51 .8

91.5

4 .25

16 .0

40 .0

80 .6

142

5.47

20 .6

51.4

104

183

295

445

Check availabil ity of large non -standard si zesCharacteristic bending stress f b = 14 .0 MPa

10

22

52

82

206

415

732

34

128

320

645

1138

44

165

412

829

1463

2358

3559

Tab le 5 .20 Section properties of d ry glulam beams GL grade

Area Weight

Bending strengthcj k 1 f b Z kNm) for k 1 =

0.60 0 .80 1.0

0 .25

0.41

0.73

0 .99

1.82

2 .90

4 . 24

0 .64

1 .54

2 .83

4.52

6 .59

0 .82

1.98

3 .64

5 .81

8.48

.7

15 .3

0.33

0.54

0.97

1.32

2 .43

3.87

5.65

0.85

2 .05

3.77

6.02

8 .79

1.09

2 .63

4 .85

7 .74

11 .3

15 .5

20.4

Bending strength

0.41

0 .68

1.21

1.65

3 .03

4 .84

7 .06

1.06

2 .56

4 .72

7 .53

10 .99

1.36

3.29

6 .06

9.68

14 .1

19.4

25 .6

Breadth DepthNo . oflams . z l cj k , fb Z kN m ) or , =

mm

6565

65

65

6565

65

65

90

9090

90

90

90

90

90

90

90

90

90

90

58

mm

180

225

270

315

360405

450

495

225

270

315

360

405

450

495

540

585

630

675

720

765

45

6

7

8

9

10

5

6

7

8

9

10

12

13

14

15

16

17

mm 2x10 3

.714 .617 .6

20 .5

23.426.329 .332 .220 .324 .3

28.432 .436 .5

40 .544 .6

48 .652 .756 .7

60.864 .8

68.9

kN/m

0.059

0 .073

0.088

0.102

0 .117

0 .132

0 .1460.161

0 .101

0.122

0.142

0 .162

0.182

0.203

0.223

0.243

0 .263

0 .284

0 .304

0.324

0 .344

mm 3 x10 6 mm • x10 9

0 .35

0 .55

0 .79

1.07

1.401.78

2 .19

2 .65

0 .76

1.09

1.49

1.94

2 .46

3 .04

3 .68

4.37

5.13

5.95

6 .83

7 .78

8 .78

0 .032

0 .062

0 .107

0 .169

0 .2530 .360

0.494

0 .657

0 .085

0 .148

0 .234

0 .350

0.498

0.683

0.910

1.18

1.50

1.88

2.31

2.80

3 .36

Nmm 2x10 2

0 .25

0.49

0 .85

1.35

2.02

2 .88

3.95

5 .26

0.681.18

1.88

2 .80

3 .99

5.47

7 .28

9.4512 .0

15 .018 .5

22 .4

26 .9

0.60

3.20

5 .00

7.20

9.8012 .816 .2

20 .024 .2

6 .93

9.97

13 .6

17 .7

22.4

27 .7

33.539 .9

46 .8

54 .3

62.3

70 .9

80 .1

0 .80

4 .27

6 .67

9 .6013 .117 .121 .626 .732 .3

9 .2313 .318 .123 .6

29.936 .9

44 .753 .2

62.4

72.483 .194 .6

107

1 .0

5 .34

8.3412 .016 .321 .327 .0

33.4

40.411 .516 .622 .629 .6

37.4

46 .2

55 .966 .5

78.090 .5

104118

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Breadth Dept hNo . oflams .

mm mm

90 810 18

90 855 19

90 900 20

- 135 270 6135 315 7135 360 8

135 405 9

135 450 10

135 495 11

135 540 12

135 585 13

135 630 14

135 675 15

135 720 16

135 765 17135 810 18

135 855 19

135 900 20

135 945 21

135 990 22

135 1035 23

135 1080 24

135 1125 25

180 270 6

180 315 7

180 360 8

180 405 9

180 450 10

180 495 11

180 540 12

180 585 13

180 630 14

180 675 15

180 720 16

180 765 17

180 810 18

180 855 19

180 900 20180 945 21180 990 22

180 1035 23

180 1080 24180 1125 25

180 1170 26180 1215 27180 1260 28180 1305 29

180 1350 3018 0 1395 31180 1440 32

NOTE S -

Thickne ss of laminations is 45mmModul us of elasticity E = 8 .0 GPa .

Area

mm 2x10 3

72 .9

77.0

81 .0

36 .542.5

48 .6

54 .7

60 .8

66.8

72 .9

79 .0

85.1

91 .1

97 .2

103109

115

122

128

134

140

146

152

48 .6

56 .7

64 .8

72 .9

81 .0

89 .1

97 .2

105

113

122

130

138

146

154

162

170

178

186

194

203

211

219

227

235

243

251

259

Weigh t z I l

kN/m mm 3 x10 6 mm • x10 9 Nmm2

x10 2

0 .365 9 .84 3. 99 31 .9

0 .385 11 .0 4 .69 37 .5

0.405 12.2 5.47 43 .7

0 .182 1 .64 0 .221 1.770 .213 2 .23 0 .352 2 .81

0.243 2 .92 0 .525 4 .20

0.273 3 .69 0 .747 5 .98

0 .304 4.56 1.03 8 .20

0 .334 5 .51 1.36 10.9

0 .365 6 .56 1 .77 14 .2

0 .395 7 .70 2 .25 18 .0

0.425 8 .93 2 .81 22.5

0 .456 10 .3 3.46 27 .7

0.486 11 .7 4 .20 33 .6

0 .516 13 .2 5.04 40 .30 .547 14.8 5 .98 47 .8

0 .577 16.4 7.03 56 .3

0 .608 18.2 8 .20 65 .6

0 .638 20.1 9.49 76 .0

0 .668 22 .1 10.9 87 .3

0 .699 24.1 12 .5 99 .8

0 .729 26 .2 14 .2 113

0 .759 28 .5 16 .0 128

0.243 2.19 0.295 2 .36

0 .284 2 .98 0.469 3 .75

0.324 3.89 0.700 5 .60

0.365 4.92 0 .996 7 .97

0.405 6 .08 1 .37 10 .9

0 .446 7.35 1 .82 14.6

0.486 8 .75 2 .36 18 .9

0 .527 10 .3 3 .00 24 .0

0 .567 11 .9 3 .75 30.0

0 .608 13 .7 4 .61 36.9

0 .648 15 .6 5 .60 44 .8

0 .689 17 .6 6 .72 53.7

0.729 19 .7 7 .97 63 .8

0.770 21 .9 9 .38 75 .0

0 .810 24 .3 10.9 87 .5

0.851 26 .8 12 .7 101

0 .891 29.4 14 .6 116

0 .932 32 .1 16 .6 133

0 .972 35 .0 18.9 151

1.013 38 .0 21.4 171

1.053 41 .1 24 .0 192

1.094 44 .3 26.9 215

1.134 47 .6 30 .0 240

1.175 51 .1 33 .3 267

1.215 54 .7 36 .9 295

1.256 58.4 40.7 326

1.296 62 .2 44 .8 358

Strength reduction factor p = 0 .8Character istic bending stress f 0 = 19.0 MPa

Bend ing str e ngthp k r. z k m for k,=

0 .60 0.8 0 1.0

89 .8 120 150

100 133 167

111 148 185

15 .0 20 .0 24 .920.4 27 .2 33 .9

26 .6 35 .5 44 .3

33.7 44 .9 56 .141 .6 55.4 69 .3

50.3 67 .0 83 .8

59.8 78 .8 00 .7

70 .2 93 .6 117

81.4 109 136

93 .5 125 156

106 142 177

120 160 200135 180 224

150 200 250

166 222 277

183 244 305

201 268 335

219 293 366

239 319 399

260 346 433

20 .0 26 .6 33 .2

27 .2 36 .2 45.3

35 .5 47 .3 59 .1

44 .9 59 .8 74 .8

55.4 73 .9 92 .3

67 .0 89.4 112

79 .8 106 133

93 .6 125 156

109 145 181

125 166 207

142 189 236

160 213 267

180 239 299

200 267 333

222 295 369

244 326 407

268 358 447

293 391 488

319 426 532

346 462 577

375 499 624

404 539 673

434 579 724

466 621 777

499 665 831

532 710 887

567 756 946

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Table 5 21 Sect ion properties of lam inated veneer lumber beams

Bre d th ep th Area Weigh t zmm mm mm x10 3 kN/m mm 3 x10 6 mm • x10 6

36 150 5.40 0 .027 0 .135 10 .13

36 200 7 .20 0 .036 0.240 24 .036 240 8 .64 0 .043 0.346 41.5

36 300 10 .8 0 .054 0.540 81 .0

45 150 6 .75 0 .034 0 .169 12 .7

45 200 9.00 0 .045 0 .30 30 .0

45 240 10 .8 0 .054 0 .432 51 .8

45 300 13 .5 0 .068 0 .675 1 1

45 360 16 .2 0 . 81 0.972 175

45 400 18 .0 0 .090 1 .2 240

63 200 12 .6 0 .063 0.42 42 .0

63 240 15 .1 0 .076 0.605 72 .3

63 300 18 .9 0 .095 0.945 142

63 360 22 .7 0.113 1.36 245

63 400 25 .2 0 .126 1 .68 336

63 450 28.4 0 .142 2 .13 478

63 600 37 .8 0 .189 3.78 1134

90 150 13.5 0 .068 0 .338 25.3

90 200 18 .0 0 .090 0.600 60 .0

90 240 21 .6 0.108 0.864 104

90 300 27 .0 0 .135 1 .35 203

90 360 32.4 0 .162 1.94 350

90 400 36 .0 0 .180 2.4 480

NOTE :See manufacturers data for strength tables and sizes produced in each strength brand .Larger sizes are possible for frame design , up to 1200mm deep .

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Tabl e 15. Section properties of steamed shaved normal density poles.

Design strength of pole in bending

Diamete r Area Dry weight z J k1 f b Z (kNm) for k 1

mm mm 2 x10 3 kN/m mm 3 x10 6 mm • x10 6 0 .6 0 .8 1 .0

75 4.42 0 .022 0.041 1.55 0 .546 0 .728 0 .910

100 7.85 0.039 0 .098 4 .91 1.29 1 .73 2 .16

125 12 .3 0 .061 0 .192 12.0 2.53 3 .37 4 .21

150 17 .7 0.088 0.331 24 .9 4 .37 5 .82 7 .28

175 24 1 0 .120 0.526 46 .0 6 .93 9 .25 11 .6

200 31.4 0.157 0.785 78 .5 10.4 13.8 17.3

225 39 .8 0 .199 1 .12 126 14 .7 19 .6 24 .6

250 49.1 0 .245 1.53 192 20 .2 27 .0 33 .7

275 59.4 0 .297 2 .04 281 26 .9 35 .9 44 .8

300 70.7 0 .353 2 .65 398 34 .9 46 .6 58 .2

325 83.0 0.415 3.37 548 44.4 59 .2 74 .0

35 0 96 .2 0.481 4.21 737 55 .5 74 .0 92 .5

375 110 0 .552 5 .18 970 68.2 91 .0 114

40 0 126 0 .628 6 .28 1256 82.8 110 138NOT E S

Tab le pre pared for machine shaved , steamed poles in the green condition with normal category outer zone density .

Cha racte ristic bending stress fb 38 MPaStrength reduction factor r J 0 .8k

4 k5 k8 1.0 for both bending and compressionMachine shaved, hence k 2 = .85 for bending, k 2 = .00 for compressionSte amed, hence k 2 = .85 for bending , k 2 = .90 for compression.For po les with high category outer zone density multiply values by appropriate stress ratio.For sh aved or unsteamed or dry poles multiply values by appropriate k factor ratio - see Table 15 .15 .

Leg islation and standardsLegi slationReleva nt legislation is available from www l egislation.govt.nz.

Th e Building Act 2004

Depa rtment of Building and Housing documentsA w ide range o building-related documents are available including:

The Building Regulations 1992 amended)Th e ew Zealand Building Code First schedule to the Building Regulations)

ew Zealand Building Code Compliance Documents and Building Code Handbook , including the fo llowing:Section B 1 Structure [88 pages]Section B2 Durability [24 pages]Section C Fire Safety [228 pages]Section E2 External Moisture [184 pages]

Wea thertightness publicationsSec tor publications

Ne w Zealand Standards and Australian/ New Zealand StandardsMos t o these are from the Standards New Zealand and Standards Australia websiteswww.s tandard .co.nz and www.standards.com.au.

Chec k these sites for updates .Important standards are list ed below in increasing numerical order , sorted into broad categories .

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STRUCTUR L CTIONS ST ND RDS

AS/NZS 1170 .0 Structural design actions General Principle sAS ZS 1170 .1Structural design actions Permanent , imposed and other actionsAS ZS 1170 .2 Structural design actions - Wind actions - Wind actionsAS/NZS 1170. 3 Structural design actions - Snow and ice actionsNZS 1170 .5 Structural design actions - Earthquake actions

TIM ER ND REL TED ST ND RDS

AS ZS I 080 . 1: 1997 Timber Methods of test Method I : Moisture contentAS/NZS I 080.2.1 : 1998 Timber Methods of test Method 2.1 : Slope of grain by scribeAS/NZS I 080 .2.2: 1998 Timber Methods of test Method 2.2: Slope of grain by reference to surface checksAS ZS I 080 .2.3: 1998 Timber Methods of test Method 2 .3: Slope of grain by splinteringAS · ZS I080.2.4:i 998 Timber Methods of test Method 2.4: Compound slope of grainAS ZS I 080 .3:2000 Timber Methods of test Method 3: DensityAS/NZS 1148 :200 I Timber omenclature Australian , New Zealand and imported speciesAS/NZS 1328 . 1:1998 Glued laminated structural timber Performance requirements and minimum production

requirements

AS ZS 1328 .2: 1998 Glued laminated st ructural timber - Guidelines for AS/NZS 1328 : Part I for the se lection , prod uctio nand installation of glued laminated structural timber .AS ZS 1491: 1996 Finger jointed structural timberAS/NZS 1604 .2: 2004 Specification for preservative treatment Reconstituted wood-based productsAS/NZS 1604 .3:2004 Specification for pre se rvative treatment PlywoodAS ZS 1604.4:2004 Specificat ion for preservative treatment - Laminated veneer lumberAS ZS 1604 .5:2 005 Specification for preservative treatment Glued laminated t imber productsAS/NZS 1605:2000 Methods for sampling and analysing timber preservatives and preservative-treated timberAS/NZS 1748:2006 Timber Mechanically stress-graded for structural purposesAS/NZS 2878:2000 Timber Classification into strength groups

ZS 360 I : 1973 Metric dimen ions for timber amended)ZS 3602 :2003 Timber and wood-based product for use in building

NZS 3603:1993 Timber Structure Standard amended)NZS 3604:1999 CD-ROM Timber Framed Buildings CD-ROM versionNZS 3604 : 1999 Timber Framed Buildings amended)

ZS 3605 :200 I Timber piles and poles for use in buildingZS 3606 : 1987 Specification for the manufacture of glue laminated timber

NZS 3607:1989 Specification for round and part-round timber fence po stsNZS 3609: 1978 Specification for timber ladder amended)NZS 3618 : 1984 Mechanical stress grading of timber

ZS 3619 : 1979 Specification for timber windowsZS 3622:2004 Verification of timber properties amended)ZS 3631 : 1988 New Zealand timber grading rules

NZS 3640:2003 Chemical preservation of round and sawn timber amended)AS/NZS 4063:1992 Timber Stress-graded- In-grade strength and stiffness evaluationS Z /PAS 4244:2003 Insulation oflightweight-framed and so lid-timber housesAS/NZS 4364:1996 Adhesives , phenolic and aminoplastic, for load-bearing timber structures: Classification and

performance requirementsAS/NZS 4490: 1997 Timber Stress-graded - Procedures for monitoring structural propertiesAS/NZS 4491:1997 Timber Glossary of terms in timber related StandardsAS/NZS 4787:200 I Timber Assessment of drying qualityAS 5068 . Timber Finger joints in structural products - Production requirements .ANSI 05 . 1-1972 Specifications and dimensions for wood poles American National Standards Institute)VENEER ND PLYWOOD ST ND RDS

AS/NZS 2097:2006 Methods for sampling veneer and plywoodAS/NZS 2098.0:2006 Methods of test for veneer and plywood - General introduction and I st of methodsAS ZS 2098.1:2006 Methods of test for veneer and plywood Moisture content of veneer and plywoodAS/NZS 2098.2:2006 Method s of test for veneer and plywood Bond quality of plywood chisel tes tAS/NZS 2098.3:2006 Methods of test for veneer and plywood - Bond quality and strength of scarf oints in plyw oodAS/NZS 2098.4:2006 Method s of test for veneer and plywood - Mea surement of dimen s ion s and shape for sheet s of veneer

and plywood

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SINZ S 2098.5:2006 Methods of test for veneer and plywood- Resi tance of gluelines in plywood to attack by micro-organisms

SINZ S 2098.6:2006 Methods of test for veneer and plywood - Depth of peeler checks in veneer and plywoodSINZ S 2098.7:2006 Methods of test for veneer and plywood- Density of veneer and plywoodSINZ S 2098.8:2006 Methods of test for veneer and plywood - Water ab orption and thickness swelling of unpainted

plyw oodSINZ S 2098.9: 1995 Methods of test for veneer and plywood - Procedures for in-grade testing of structural p lywood

SINZ S 2098.11 :2005 Methods of test for veneer and plywood -Determination of formaldehyde emissions for plywoodSINZ S 2269:2004 Plywood - Structural amended)SINZ S 2270:2006 Plywood and b lackboard for interior useSINZ S 2271 :2004 Plywood and blackboard for exterior use amended)SINZ S 2272:2006 Plywood - Marine

N TED VENEER LUMBER ST ND RDS

SIN ZS 4357.0:2005 Structural laminated veneer lumber - SpecificationsS /N ZS 4357.1 :2005 Structural laminated veneer lumber- Method of test for measurement of dimension and shapeS /N ZS 4357 .2:2006 Structural laminated veneer lumber LVL)- Determination of structural properties- Test methods

ame nded)S /N ZS 4357.3:2006 Structural laminated veneer lumber LVL)- Determination of structural properties- Evaluation

met hodsS /N ZS 4357.4:2005 Structural laminated veneer lumber- Determination of formaldehyde emis ions

FIRE ST ND RDS

S ZS 1530.3 : 1999 Methods for fire tests on building materials , component and structures- Simultaneous determinationof ignitability, flame propagation , heat release and smoke release

S 1530.4:2 005 Methods for fire tests on building materials , components and structures- Fire-resistance test of elementsof co nstruction

O th er impor t nt timb er sta n a r s

ISO an d ASTM standards are used in Australia and ew Zealand for a range of testing procedures for ew Zealand andove rse as markets and some of these standards have been used in the development of ew Zealand and Australasianstandards.

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Chapter 15 Design Data

Documents

Transcript of Chapter 15 Design Data