Design of Long-Span Truss

Loads, Building data and Material Properties

Loading: NSCP 2010

Minimum Design Loads

Table 1. Minimum Design Dead Loads

ComponentCeillings

Plaster on Tile or Concrete 0.24Acoustical Fiber Board 0.05Suspended metal lath and gypsum plaster 0.48Mechanical Duct Allowance 0.20

Covering, Roof and WallAsphalt Shingles 0.10Insultaion (Urethane foam w/ Skin) 0.0009Insultaion (Polystyrene foam) 0.0004Water proofing membrane, Bituminous (smooth surface) 0.07Cement tile Finished 0.77

Floor and Floor FinishesCeramic or Quarry Tile (20mm) 0.77Marble and mortar on stone-concrete 1.58Lightweight concrete, plain per mm 0.02Linoleum or Asphaltic tile, 6mm 0.05Subflooring, 19mm 0.14

Frame Partitions and WallsExterior stud walls with brick veneer 2.30Windows, glass, frame and sash 0.38Wood studs 2 x 4 in., ( 50 x 100 mm) plastered two sides 0.96Wood studs 2 x 4 in., ( 5 x 10 mm) unplastered 0.19

Concrete Masonry units (Wall)Masonry, Normal weight 21.20Masonry Lightweight solid concrete 16.50

Table 2. Minimum Design Live LoadsUse or Occupancy Unit Load

Category DescriptionResidential

Basic Floor Area 1.90Bedrooms 2.00Exterior Balconies 2.90Decks 1.90Storage 1.90

Restrooms ---- ---- 2.87Stairs --- ---- 2.00

Table 3. Special LoadsUse or Occupancy Lateral load

Category DescriptionBalcony Railings & guardrails

Exit Facilites 0.75Other than exit facilities 0.30components 1.20

Partitions & interior walls 0.25

Unit Load, KN/m2

KN/m2

KN/m2

Table 4. Minimum Roof Live Loads

Table 5. Minimum Densities for Design Loads

MaterialAluminum 26.70Cement Board 7.10Plywood 5.70Laminated Red Wood (1/2") 28.00Mortar Cement or lime (2") 20.40

Load Combinations: ASD

1.) D D = Dead Load2.) D + L L = LiveLoad3.) D + (Lr or S or R) Lr = Roof Live Load4.) D + 0.75L + 0.75(Lr or S or R) R = Rain Load5.) D + (W or 0.7E) W = Wind Load6.) D + 0.75(W or 0.7E) + 0.75L + 0.75(Lr or S or R) E = Earthquake Load

Analysis:

Material Property:

Wood : Bayok

Grade = 63.00 % stress

Fb= 9.94 Mpa

Fc= 5.78 Mpa

Fv = 0.95 Mpa

Density,KN/m3

Microsoft Excel 2010 and Graphical Rapid Analysis of Structures Program (GRASP) were used to anlyze basic and complex structures such as Purlins, Trusses, Beams and Girders, Columns, Trusses. (See Design Aids)

Es = 3.94 Gpa

G = 0.44 Relative Density

Design Aids

Analysis of Purlins:

Pitch = h/L

tanθ=(h/(L/2))Wind Load:

Method 1: Ps = λKztIwPs9

Method 2: qz = 0.0000473KzKztKdIwV2

Simplified ASCE: θ > 10o

Windward: Pn = P(1.3sinθ-0.5) Leeward: Pn = -0.6P (Suction)

Duchemins Formula: Pn = (2P sinθ)/(1+sin2θ)

(See Appendix A)

Bending Stress:

Mn = WnLx2/8 ; fn = 6Mn/bd2Mt = WtLy2/8 ; ft = 6Mt/b2dfb = fn + ft < Allowable bending stress (Fb)

Shearing Stress:

vn = 3Vn/2bdvt = 3Vt/2bdfv = √((vn)2+(vt)2) < Allowable shearing stress (Fv)

Deflections:

LiveLoad: yall = L/360 > yact

DeadLoad + LiveLoad: yall = L/240 > yact

Analysis of Trusses:

Assumptions:

Tenion Stress:

ft = P/An<F′t ; F't = CDCMCTCFCiFt

Compression Stress:

fc = P/Ag <F^′ cSlenderness Factor Adjustments:

Where:

Ps - Horizontal pressure (Windward & Leeward).λ - Adjustment factor for building height and exposure.Kz - Velocity exposure coefficient.Kzt - Topographic factor.Kd - Wind directionality factor.Iw - Importance factor.Ps9 - Simplified design wind pressure for exposure B @ h = 9, Iw = 1 (NSCP, fig.207-3).qz - Velocity pressure @ height z.V - Wind velocity (Kph)Pn - Wind pressure perpendicular to surface.Mn - Normal Moment.Mt - Tangential Moment.fn - Normal Stress.ft - Tangential Stress.v - Shearing stress.lu - Unsupported length.Ag - Gross Area.Ft - Allowable tensile stress.Fc - Allowable compression stress.Fb - Allowable bending stress.Fv - Allowable shearing strress.CD - Load duration Factor.CM - Wet service factor (CM=1,for dry safe factor).CT - Temperature factor (CT=1,for normal temp.).CF - Size factor(CF=1,for sawn lumber).Ci - insicing factor(Ci=0.8,for incised;Ci=1,for not incised).Cs - Slenderness factor.Ck - Support factor.

Analysis of Purlins:

Pitch = h/L

tanθ=(h/(L/2))Wind Load:

Method 1: Ps = λKztIwPs9

Method 2: qz = 0.0000473KzKztKdIwV2

Simplified ASCE: θ > 10o

Windward: Pn = P(1.3sinθ-0.5) Leeward: Pn = -0.6P (Suction)

Duchemins Formula: Pn = (2P sinθ)/(1+sin2θ)

(See Appendix A)

Bending Stress:

Mn = WnLx2/8 ; fn = 6Mn/bd2Mt = WtLy2/8 ; ft = 6Mt/b2dfb = fn + ft < Allowable bending stress (Fb)

Shearing Stress:

vn = 3Vn/2bdvt = 3Vt/2bdfv = √((vn)2+(vt)2) < Allowable shearing stress (Fv)

Deflections:



Analysis of Trusses:

Assumptions:

Tenion Stress:

ft = P/An<F′t ; F't = CDCMCTCFCiFt

Compression Stress:

fc = P/Ag <F^′ cSlenderness Factor Adjustments:

Analysis of Beams:

Bending Stress:

fb = 6M/bd2 < F'b

Slenderness Factor Adjustments:

(See Table 7 for value of le)

Size Factor Adjusment: d > 300mm

CF = (300/d)^(1/9) ; d =depth of Beam in mm

fb = fb*CF

Shearing Stress:

fv=3V/2bd <FvIf notched beams:

fv=3V/2bd′ (d/d′) <FvDeflections:



Analysis for Columns:

Compression Stress:fc = P/Ag <F^′ cSlenderness Factor Adjustments:

(See Table 6 for value of k)

Table 6. Buckling Factors Ke:

Table 7. Effective Length of Beams

Klu = le

Table 8. Load duration factor

NSCP 2010: Wind Loads

Guidelines for Tile Toilet & Bathroom

Subfloor, Floor Joist, and Plumbing pipes

Waterproofing of wall and floor

Installation of Tiles

1.) Install Plyboard (3/4"-1") and plumbing pipes.

2.) Lay down tar paper or plastic on the floor to preserved the wood floor from sucking to the moisture of the mortar berfore it dries. It is also important to nail down wire mesh to give the mortar extra strength.

3.) Mix mortar (Portland cement) and apply about 2" thick properly from the walls to the drain with fair amount of slope so that water flows out into the drain without making puddles. Let this dry for about 24 hours.

4.) Put rubber membrane (CPE) to make waterproof seal. Install cement board in wall properly with 1/4" clearance between the cement board and the membrane. Then repeat step 3.

* You can use alternative material in waterproofing for economy.

Soure: www.google.com

5.) Seal or tape the cement board joints in wall with special adhesive netting. Then put one layer of cement board compound and let it dry for about 24 hours. Install the tiles using available adhesive cement or mortar properly from walls to the drain.

Factored Load used:

Wu = 1.2DL + 1.6LL

Ultimate Shear & Moments:

A. Analysis by The Coefficient Method A.1 One way slabs & Continuous Beams (ACI CODE Section 408.4.3)

A.2 Two way slabs (Design of Concrete Structures,12 ed., Arthur H. Nilson)

Where:

Tabulated Moment Coefficients

uniform factored load

Length of clear span in Short direction

Length of clear span in Long direction

Ca, Cb =

wu =

La =

Lb =

Ma = Ca wu La

2

Mb = Cb wu Lb2

Va = Ca wu La2

Vb = Cb wu Lb

2

Positive Moment:End Spans Discontinuous end unrestrained wuln

2/11 Discontinuous end InteGral with Support wuln

2/14Interior Spans

Negative Moment:at exterior face of first interior support Two spans wuln

2/9 More than two spans wuln

2/10at other faces of interior supports wuln

2/11at face of all supports for slabs with spans not exceeding3 meters; and stiffness to beam stiffness exceeds eight at eachend of the span wuln

2/12at interior face of exterior supports for members builtintegrally with supports: where support is a spandrel beam wuln

2/24 where support is a column wuln

2/16

Shear:at face of first interior supports 1.15wuln/2at face of all other supports wuln/2

*ln - clear span

Where:

Ps - Horizontal pressure (Windward & Leeward).λ - Adjustment factor for building height and exposure.Kz - Velocity exposure coefficient.Kzt - Topographic factor.Kd - Wind directionality factor.Iw - Importance factor.Ps9 - Simplified design wind pressure for exposure B @ h = 9, Iw = 1 (NSCP, fig.207-3).qz - Velocity pressure @ height z.V - Wind velocity (Kph)Pn - Wind pressure perpendicular to surface.Mn - Normal Moment.Mt - Tangential Moment.fn - Normal Stress.ft - Tangential Stress.v - Shearing stress.lu - Unsupported length.Ag - Gross Area.Ft - Allowable tensile stress.Fc - Allowable compression stress.Fb - Allowable bending stress.Fv - Allowable shearing strress.CD - Load duration Factor.CM - Wet service factor (CM=1,for dry safe factor).CT - Temperature factor (CT=1,for normal temp.).CF - Size factor(CF=1,for sawn lumber).Ci - insicing factor(Ci=0.8,for incised;Ci=1,for not incised).Cs - Slenderness factor.Ck - Support factor.

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: A. Design of Purlins Checked By:Purlins - Roof Framing Plan Rating:

Material Property: Model: Truss - T1

Wood = Bayok Grade = 63.00 % stress

Fb= 9.94 MpaFc= 5.78 Mpa

Fv = 0.95 MpaEw = 3.94 GpaGw = 0.44

Assume Section: Spacing (s1) = 1.20 mb = 75 mm Spacing (s2) = 1.12 md = 200 mm height (h) = 3.00 m

Length (L/2) = 8.00 m (consider half-span)20.56 degress

Service Loads:

Dead loads: KN/mWeight of Purlin 4.32 0.06Asphalt Shingles 0.10 0.11

0.18

Live Loads: KN/mRoof Slope : 20.56 degrees 0.75 0.84

0.84

Wind Loads: Method 2Zone: 2 Wind Pressure :

V = 200 Kph 1.892 KpaKz = 1.00

Kzt = 1.00 Load Windward Leeward

Kd = 1.00 Pn -0.082 0.049Iw = 1.00 Wn -0.099 0.059 KN/m

Loading:Load Combinations Normal (Wn) Tangential (Wt) Condition1. D 0.166 0.062 ---2. D + Lr 0.955 0.358 governs3. D + 0.75Lr + 0.75 W 0.684 0.210 ---

Sectiion:

Along XWn = 0.95 KN/m

L = 4.00 mLx = 4.00 m

Along YWt = 0.36 KN/m

L = 4.00 mLy = 4.00 m

KN/m3 KN/m2

DLtotal

KN/m3 KN/m2

LLtotal

qz = 0.0000473kzkztkdV2Iw =

KN/m2

s2

s1

L

h

θ=tan 〖 -1 〗(h/L) =

WDr , Lr

Wp= bhɣ

*Pn=P(1.3sinϴ-0.5) , Windward*Pn=-0.6P , Leeward

Wmat^′ l=unit load x s2

Wl=unit load x s2

Design Loads:

Mn = 1.367 KN-m

Mt = 0.420 KN-m

Check for Bending Stress:

fn = 2.734 Mpa

ft = 2.242 Mpafb = fn + ft = 4.976 Mpa

fb < Fb, Safe!

Check for Shearing Stress:

Vn = WnLx/2 = 1.91 KNVt = WtLx/2 = 0.72 KNvn = 1.5Vn/bd = 0.19 Mpavt = 1.5Vt/bd = 0.07 Mpa

0.20 Mpafv < Fv, Safe!

Check for Deflection:

L / 240 = 16.67 mm

16.16 mmyact < yall, Safe!

Use:

Purlins: 75 x 200 mm (Bayok lumber)

* Adapt the size of member to other purlins for aesthetic design.

WnLx2/8 =

WnLy2/8 =

6Mn/bd2 =

6Mt/b2d =

yall =

yact = 5WnL4/384EI =

fv=√(〖 vn〗^2+〖 vt〗^2 )=

Wl=unit load x s2

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: B. Design of Truss Checked By:T1 - Roof Framing Plan Rating:

Material Property: Model: Truss - T1

Wood = Bayok Grade = 63.00 % stress

Fb= 9.94 MpaFc= 5.78 Mpa

Fv = 0.95 MpaEw = 3.94 GpaGw = 0.44

Assume Section:For wood :Top Chord : 2 pccs

b = 25 mmd = 200 mm Spacing (s) = 1.20 m

Bottom Chord : 2 pcs height (h) = 3.00 mb = 25 mm Length (L/2) = 8.00 md = 200 mm 20.56 degress

Web : 1 pcsb = 25 mmd = 150 mm

For Steel :

77.3s =∅ 16 mm

Fy = 248 Mpa

Service Loads:

Dead loads: KN/m

Weight of Truss 4.32 0.1025

(Assumed)

0.10

Live Loads: KN/mRoof Slope : 20.56 degrees ---- ---- 0.00

0.00

Design Loads:w = DL = 0.10 KN/m

Loads from Purlins (Rp) = 1.5Vncosθ = 2.68 KN

ws = KN3

KN/m3 KN/m2

DLtotal

KN/m3 KN/m2

LLtotal

θ=tan 〖 -1 〗(h/L) =

s

L

h

RP D

WT= bhɣ

A

B

C

D

E

F

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Design Loads:

Description Member L (mm) Forces (KN)Top Chord AB 2670.00 10000 35.4Bottom Chord JH 2000.00 10000 6.1Diagonal Web FH 3010.00 3750 7.5Vertical Web FH 3000.00 201.06 8.6* Choose Maximum Axial Load (GRASP)Tensile Stress:

Compressive Stress:


0.300 visually graded

0.418 machine stress graded sawn lumber

Design for Truss Member:

Top Chord:

Compressive Stress: Tensile Stress:k= 1.00 Hinge support CD = 1.25

klu/d = 6.68 Cs ≤ 50, Ok! CM = 1.00CT= 1.00

17.52 CF= 1.00Ci= 1.00

case 1: klu/d ≤ 11 F't = 12.42 Mpaft = 1.77 Mpa

F'c = 5.78 Mpa ft < Ft, Safe!fc = 1.77 Mpa

fc < F'c, Safe!

Bottom Chord:

Compressive Stress: Tensile Stress:k= 1.00 Hinge support CD = 1.25

klu/d = 40.00 Cs ≤ 50, Ok! CM = 1.00CT= 1.00

17.52 CF= 1.00

Ci= 1.00

case 3: klu/d ≥ K F't = 12.42 Mpaft = 0.31 Mpa


fc < F'c, Safe!

Diagonal Web:Compressive Stress: Tensile Stress:

k= 1.00 Hinge support CD = 1.25klu/d = 20.07 Cs ≤ 50, Ok! CM = 1.00

CT= 1.0017.52 CF= 1.00

Ci= 1.00

Area (mm2)

KcE =

KcE =

ft=P/0.6An ≤ F′t ; F't = CDCMCTCFCiFt ; Ft = Fb

fc=P/Ag ≤ F'c

case 1: klu/d ≤11 ; F'c = Fc

case 2: 11 ≤ klu/d ≤K ; K = 0.671√(E/Fc) ; F'c = Fc[1-1/3 ((klu/d)/K)^4 ]case 3: klu/d ≥K ; F'c = (KcE E)/(klu/d)^2

K = 0.671√(E/Fc) =

K = 0.671√(E/Fc) =

K = 0.671√(E/Fc) =

K = 0.671√(E/Fc) =

K = 0.671√(E/Fc) =

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case 3: klu/d ≥ K F't = 12.42 Mpaft = 1.00 Mpa


fc < F'c, Safe!

Ft = 0.60FyFt = 148.8 Mpa

ft = F/Asft = 42.77 Mpa

ft < Ft, Safe!Use:

Top Chord: 2 - 25 x 200 mm (Bayok lumber)Bottom Chord: 2 - 25 x 200 mm (Bayok lumber)Diagonal Web: 1 - 25 x 150 mm (Bayok lumber)Vertical Web: 16 mm Plain Steel bars∅

16 mm Plain Steel bars∅2 - 25 x 200 mm (Bayok lumber)

2 - 25 x 200 mm (Bayok lumber)

1 - 25 x 150 mm (Bayok lumber)

Note: Adapt all sizes of member to other types of truss for aesthetic design.

Diagonal Web: Steel

A

BC

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: C. Design of Truss Joints Checked By:Joint A - Truss T1 Rating:

Material Property: Model: Anchor Bolts Connections

Wood : Bayok Grade = 63.00 % stress

Fb= 9.94 MpaP= 5.78 Mpa

Q = 1.03 MpaFv = 0.95 Mpa

Ew = 3.94 GpaGw = 0.44

Steel :Ft = 148.80 Mpas =∅ 16 mm

T = 8.6 KNθ = 20.56 degrees

Check if Steel is adequate :

ft = T/Asft = 42.77 Mpa

ft < Ft, Safe!

Compressive Stress @ section AB ( r ) :

Figure:

r = 1.62 Mpa

Size of Washer :

Required Net Area : Figure:

An = T/r

An = 5322.34

Diameter of hole :

18 mm

Gross Area :

Ag =

Ag = 5576.80

5576.8074.68 mm

say : 80 mm

mm2

∅hole = ∅bolt + 2mm∅hole =

An + Ahole

mm2

X2 = mm2

X =

A B

DesignDesign

r=P〖 sin〗^2 θ+Q〖 cos〗^2 θ , Jacoby's Formula

XDn

X

T

r r

A B

Thickness of Washer :

Dn = 1.5 + 3∅ Figure:Dn = 27 mm

T1 = T2 = T/2T1 = T2 = 4.3 KN

Dn/47 mm

18 mm

M =M = 48.375 KN-m

ft =

ft =

t = 5.61 mm b =say : 6 mm b = 62 mm

Use:

Steel : 124.00 Mpa

s =∅ 22 mm

Washer :t = 6 mm

27 mm 80 mm

80 mm

x1 =x1 =x2 = ∅hole

x2 =

T2 (x2) - T1 (x1)

6M/bd2 , Ft =ft

6M/bt2

X - ∅hole

Fbs =

T

A B

T1

T2

x1

x2

∅holeA B

∅hole

X

B

B

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: D. Design of Truss Joints Checked By:Joint B - Truss T1 Rating:

Material Property: Model: Splicing Connections @ Bottom Chord


Fb = 9.94 MpaP = 5.78 MpaQ = 1.03 Mpa

Fv = 0.95 MpaEw = 3.94 GpaGw = 0.44

F = 6.10 KNBolt :

12 mmGroup = I

8.38 KN4.70 KN

Figure : Main member 50 200 mm

3.05 KN

6 KN

3.05 KN

Side Plate 50 200 mmNo. of Bolts :

n =n = 0.73 pcs

Say : 12 pcsNo. of rows : 2

Check for Tension :

ft = F/An ,Fb = Ft Ag = bh (main member)

ft = 0.71 Mpa Ag = 10000ft < Ft, Safe!

14An =

An = 8600

Check for Bolt Shear :

Pv =Pv = 100.56 KN

Pv > F, Safe!

Check for Bearing of bolt to main member :

fb = F/(Ap*n) Ap =

fb = 0.85 Mpa Ap = 600

∅b =

Pb =Qb =

F/Pb

mm2

Ahole = ∅bolt + 2mm

Ahole = mm2

Ag - ∑Ahole

mm2

nbolt x Pb

∅bolt x t , t = bmain member

mm2

DesignDesign

FF

x

x

b h

b h

fb < P, Safe!

Use :12 mm

12 pcs

12-12mm Bolts∅

∅bolt =

nbolts =

FF

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: D. Design of Truss Joints Checked By:Joint C - Truss T1 Rating:

Material Property: Model: Splicing Connections @ Top Chord


Fb = 9.94 MpaP = 5.78 MpaQ = 1.03 Mpa

Fv = 0.95 MpaEw = 3.94 GpaGw = 0.44

F = 35.40 KNBolt :

16 mmGroup = I

10.80 KN5.23 KN


17.7 KN

35 KN

17.7 KN


n =n = 3.28 pcs

Say : 8 pcsNo. of rows : 2

Check for Tension :

ft = F/An ,Fb = Ft Ag = bh (main member)

ft = 4.32 Mpa Ag = 10000ft < Ft, Safe!

18An =

An = 8200


Pv =Pv = 86.4 KN

Pv > F, Safe!


fb = F/(Ap*n) Ap =

fb = 5.53 Mpa Ap = 800

∅b =

Pb =Qb =

F/Pb

mm2

Ahole = ∅bolt + 2mm

Ahole = mm2

Ag - ∑Ahole

mm2

nbolt x Pb


mm2

DesignDesign

FF

x

x

b h

b h

fb < P, Safe!

Use :16 mm

8 pcs

8-16mm Bolts∅

∅bolt =

nbolts =

FF

Truss @ Painitan Section,Palao Market,Iligan City Date Prepared: E. Design of Truss Joints Checked By:Joint B - Truss T1 Rating:

Material Property: Model: Notching Connections


Fb = 9.94 MpaP = 5.78 MpaQ = 1.03 Mpa

Fv = 0.95 MpaEw = 3.94 GpaGw = 0.44

F = 7.5 KNθ = 50 degrees

Web member 50 150 mm

8 KN

50 mm

Bot. Chord 50 200 mm

Check if dap is adequate :

Compressive Stress perpendicular to AB : Actual comp. Stress @ AB:

AC = h/sinϴ F1 = FsinβAC = 150/sin(50) F1 = 4.26 KNAC = 195.81 mm

r = AC/2 F1/A1r = 97.91 mm 0.45 Mpa

α = 0.5asin(dap/r) Check with allowable comp. stress (r ):α = 0.5asin(50/97.91)α = 15.36 degrees φ = 90 - αβ = 34.64 degrees φ = 74.64 degrees

AB = cosα(AC) AB = 188.82 mmA1 = AB*b r = 1.093 MpaA1 = 9441.06 r > fab, Safe!

fAB =fAB =

mm2

F

DesignDesign

xb h

xb' h

r=PQ/(P〖 sin〗^2 φ+"Q" 〖 cos〗^2 φ)

b′

A1A1

A2A2

θ

b

BCdap=

AB

rr

Compressive Stress perpendicular to BC :

BC = sinα(AC) BC = 51.851 mmA2 = BC*b'A2 = 2592.55

Actual comp. Stress @ AB: Check with allowable comp. stress (r ):

F2 = Fcosβ α = 15.36 degreesF2 = 6.17 KN

F2/A22.38 Mpa r = 4.368 Mpa

r > fab, Safe!Percent correction :

%cor. =%cor. = 54.491

corrected dap = 27.25 mmTry: dap = 50 mm

Use :

Web member 50 x 150 mm8 KN

50 mm

Bot. Chord 50 x 200 mm

mm2

fBC=fBC =

fBC/r

r=PQ/(P〖 sin〗^2 φ+"Q" 〖 cos〗^2 φ)

θdap=

Service Loads:

Dead loads: KN/mWeight of Truss 4.32 0.0000Ceiling 1.0000 (Assumed)

1.00

Live Loads: KN/moof Slope : degrees ---- ---- 0.00

0.00

Design Loads:w = DL = 1.00 KN/m

0.83 KN

Analysis: Using Graphical Rapid Analysis of Structures Program (GRASP)

Reaction @ Supports:

Member Axial Forces:

Design Loads:

Descriptio Member L (mm) Forces (KN)Top Chord AB 2150.00 0 0 9.3Bottom Ch AC 1400.00 0 0 2.7Web FI 2350.00 0 0 4.7* Choose Maximum Axial Load (GRASP)

Tensile Stress:

KN/m3 KN/m2

DLtotal

KN/m3 KN/m2

LLtotal

Area (mm2)Inertia (mm4)

WT= bhɣ


Loads from Purlins (Rp) =1.5Vncosθ =

Compressive Stress:


0.300 visually graded

0.418 machine stress graded sawn lumber

Design for Truss Member:

Top Chord:

Compressive Stress: Tensile Stress:k= 1.00 Hinge support CD = 1.25 (Refer Table 8.)

klu/d = #DIV/0! #DIV/0! CM = 1.00CT= 1.00

17.52 CF= 1.00 (See Design Aids)Ci= 1.00

#DIV/0! F't = 12.42 Mpaft = #DIV/0! Mpa

F'c = #DIV/0! Mpa #DIV/0!

fc = #DIV/0! Mpa

#DIV/0!

Bottom Chord:


klu/d = #DIV/0! #DIV/0! CM = 1.00CT= 1.00



F'c = #DIV/0! Mpa #DIV/0!fc = #DIV/0! Mpa

#DIV/0!

KcE =

KcE =


fc=P/Ag ≤ F'c

case 1: klu/d ≤11 ; F'c = Fc

case 2: 11 ≤ klu/d ≤K ; K = 0.671√(E/Fc) ; F'c = Fc[1-1/3 ((klu/d)/K)^4 ]case 3: klu/d ≥K ; F'c = (KcE E)/(klu/d)^2

K = 0.671√(E/Fc) =

K = 0.671√(E/Fc) = K = 0.671√(E/Fc) =

Web:


klu/d = #DIV/0! #DIV/0! CM = 1.00CT= 1.00



F'c = #DIV/0! Mpa #DIV/0!fc = #DIV/0! Mpa

#DIV/0!

Use:Top Chord: - x mm (Bayok lumber)tom Chord: - x mm (Bayok lumber)

Web: - x mm (Bayok lumber)

* Adapt all sizes of member to other types of truss for aesthetic design.


#REF! KN

#REF! KN

#REF! KN


n =n = ### pcs

Say : 12 pcs

No. of rows : 3

Check for Tension :

F/Pb

K = 0.671√(E/Fc) = K = 0.671√(E/Fc) =

DesignDesign

x

x

b d

b d

ft = F/An ,Fb = Ft Ag = bd (main member)

ft = ### Mpa Ag = 25000###

24 mmAn =

An = 17800


Pv =Pv = 261.6 KN

#REF!


fb = F/(Ap*n) Ap =fb = ### Mpa Ap = 2200 mm

###

Use :22 mm12 pcs

Project Title : Long Span Truss Design Date Prepared : Sept - 29 - 2012Section : Design of Notch Connection Date Submitted :Subsection : Design of Notch of Connection A Rating :

Structure DataWeb Member Detail:

b = mmh = mmϴ = ◦

Chord Member Detail:

mmmm

Member Properties :MPaMPa

Load

mm2

Ahole =∅bolt + 2mmAhole =

Ag - ∑Ahole

mm2

nbolt x Pb


∅bolt =nbolts =

NOTE : ϴ is the angle of inclination of the web member with respect to the horizontal

bc =hc =

Fc|| =FcL =

P = kN

Assume depth of Dap :hd = mm

Analysis

T = 30 KN

θ = 30 degrees

Bayok



ft > Fbs, Not Safe!

Compressive Stress @ section AB ( r ) :Figure:

r = 2.22 Mpa

Size of Washer :


An = T/r

An = 13528.75

Diamete of hole :

mm2


10 mm

Gross Area :

Ag =

Ag = 13613.37

13613.37116.68 mm

say : 120 mm


Dn = 1.5 + 3∅ Figure:Dn = 15.57 mm

T1 = T2 = T/2T1 = T2 = 15 KN

Dn/44 mm

10 mm

M =M = 97.3125 KN-m

t = 21.07 mm b =say : 12 mm b = 110 mm

Use:

Steel : 124.00 Mpa

s =∅ 22 mm

Washer :

∅hole =

An + Ahole

mm2

X2 = mm2

X =

x1 =x1 =x2 = ∅hole

x2 =

T2 (x2) - T1 (x1)

fbs = 6M/bd2 , Fbs =fbs

fbs = 6M/bt2

X - ∅hole

Fbs =

∅hole

15.57 mm 120 mm

120 mm



ft > Fbs, Not Safe!

Compressive Stress @ section AB ( r ) :Figure:

r = ### Mpa

Size of Washer :


An = T/r

An = ###

Diamete of hole :

24 mm

Gross Area :

Ag =

Ag = ###

###### mm

mm2

∅hole =

An + Ahole

mm2

X2 = mm2

X =


say : 120 mm


Dn = 1.5 + 3∅ Figure:

Dn = 35.7 mm

T1 = T2 = T/2T1 = T2 = 15 KN

Dn/49 mm

24 mm

M =M = 223.125 KN-m

t = 25.15 mm b =say : 12 mm b = 96 mm

Use:Sept - 29 - 2012

Steel : 124.00 Mpa

s =∅ 22 mm

Washer :

35.7 mm 120 mm

Group = I

120 mm

x1 =x1 =x2 = ∅hole

x2 =

T2 (x2) - T1 (x1)

fbs = 6M/bd2 , Fbs =fbs

fbs = 6M/bt2

X - ∅hole

Fbs =

∅hole

Bolt :

2221.807.21

∅b =Pb =Qb =

1

Material Property:

Wood : Bayok

Grade = 63.00 % stress

Fb= 9.94 Mpa

Fc= 5.78 Mpa

Fv = 0.95 Mpa

Es = 3.94 Gpa

G = 0.44 Relative Density

Steel:Fy = 248.00 Mpa

s =∅ 16 mm

Bolts :

Group = I

12 mm 16 mm

8.38 KN 10.80 KN

4.70 KN 5.23 KN

∅b = ∅b =

Pb = Pb =

Qb = Qb =

Documents

Design of Long-Span Truss