robert jonkman, p.eng. - wood-works material, span details bearing ... provided that the maximum...

Canadian Wood Council | cwc.ca November 2012

Robert J Jonkman, P.Eng. | woodworks-software.com 1

Robert Jonkman, P.Eng.

November 20, 2012, Toronto Wood Solutions Fair

SHEARWALLS

CONNECTIONS

SIZERGravity Design

Lateral Design (Wind and Seismic)

Fasteners

Concept mode

Beam modeColumn mode

DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US

Add proprietary products

Electronic copy of CSA O86 included with purchase of Design Office suite

Latest version:Design Office 8 SR1(May 22, 2012 - 8.11)

Automatic wind and seismic load generation

Distribute using rigid and flexible diaphragm distribution methods

SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US





SIZER-Concept

Elevation view Plan view

SIZER-Concept

Transfer HIP load information to Beam mode

SIZER-Beam

Transferred Length and Slope to Beam mode

SIZER-Beam

Transferred HIP load info to Beam mode

SIZER-ConceptExample

SIZER-ConceptExample



SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US



• Simply Supported

• Multi-Span Continuous

• Cantilevers

• Biaxial bending members (such as oblique purlins)

Detailed Design of Beams, Joists, Rafters

SIZER-Beam

SIZER-Beam

Beam input

Size, material, span Details Bearing Support

SIZER-Beam

Beam input

Size, material, span

SIZER-Beam

Size, material, span

SIZER-Beam Span type: Design, Clear, Full

Design span: centre to centre of bearingClear: inside to inside of bearingFull: outside to outside of bearing



SIZER-Beam

Beam input

Details

SIZER-Beam

Details:Notches, deflection, wet, treatment, lateral support

NBCC 9.23.5.2. Notching of Framing Members(1) …members are permitted to be notched provided the notch islocated on the top of the member within half the joist depth from theedge of bearing and is not deeper than one‐third the joist depth…

Notches and Part 9 Notches (compression zone) and Part 4

5.5.5 Shear resistance5.5.5.1 General

An = net area of cross-section, mm2 (Clause 4.3.8)

4.3.8.2 LimitationThe net section shall not be less than 75% of the gross section

Notches (tension zone) and Part 4 Notches (tension zone) and Part 4



SIZER-Beam

Beam input

Bearing Support

SIZER-Beam Bearing supports

SIZER-Beam

Load input

Loads Load details

Loads

SIZER-BeamLoad details

SIZER-BeamLoad details



Lateral Stability factor KL

5.5.4.2 Lateral stability factor, KL5.5.4.2.1The lateral stability factor, KL , may be taken as unity when lateral support is provided at points of bearing to prevent lateral displacement and rotation, provided that the maximum depth-to-width ratio of the member does not exceed the following values:(a) 4:1 … (b) 5:1 … (c) 6.5:1… (d) 7.5:1 or… (e) 9:1 if both edges are held in line.

Alternatively, KL may be calculated in accordance with Clause 6.5.6.4.

SIZER-Beam

Lateral Stability factor KL

SIZER-Beam

Holes9.23.5.1. Holes Drilled in Framing Members

(1) Holes drilled in roof, floor or ceiling framing members shall be not larger than one-quarter the depth of the member and shall be located not less than 50 mm from the edges, unless the depth of the member is increased by the size of the hole.

Shear and moment at user-defined locations

Points of InterestSIZER-Beam

Steel beams

SIZER-Beam

2009 CSA-S16-09 SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US





• Columns & Walls

• Eccentric loading

• Compression & Tension

• Axial / Lateral Loads

• Fixed or Pinned

SIZER-Column SIZER-Column

Eccentric Loads

SIZER-Column

Fixed or Pinned BaseFull support, unbraced, or specify distance

SIZER-Column

Load face can be the width or depth of columns or studs

Links to Sizer: Links to Sizer:



SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US



DATABASE EDITOR

DATABASE EDITOR

Proprietary databases for use in generic Sizer:Ask your SCL manufacturer…

http://www.taigaewp.com/Software/Woodwork_databases.htm http://www.taigaewp.com/Software/Woodwork_databases.htm

C:\Users\rjonkman\AppData\Local\Woodworks\CWC\Canada\8



http://www.taigaewp.com/Software/Woodwork_databases.htm http://www.taigaewp.com/Software/Woodwork_databases.htm

Custom versions of Sizer:

SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US





Automatic Wind and Seismic Load Generation:

Enter city OR

Enter reference information from Building code

Additional loads can be added manually

SHEARWALLS SHEARWALLS

Distributes the automatically generated loads to each shear wall

Designs for wind suction

Designs for shear

Rigid diaphragm(Stiffness)

Flexible diaphragm(Tributary area)

CAD Import in Windows Metafile format (.wmf)

SHEARWALLS(.pdf coming next version)

• Traditional Holddowns each Segment

• Some or all Hold-downs omitted, anchorage used –rely on sheathing transferring tension

Hold-downs

OR

SHEARWALLS

Demo: Basics of shearwalls• Example.wmf template

• Manual load addition

• Automatic load generation based on location

• Log file additional calculations

• .wmf (windows metafile)

• Single wall check

• Timesaver: specify complete wall to reduce wall types, show failed wall

• Dragstrut, hold downs

• Ignore GWB for seismic, Rd = 3 or 2

• C&C check

• Wind design method (I7 or I15).

SHEARWALLS

Design tab: Wind design code options



Manual Load Input

Plan view

Elevation view

Plan view

Components and cladding (C&C): 20.4 psf (unfactored)

3664 lbs = shear wall force factored

Shear load distribution at ceiling level: 155.1 plf maximum (unfactored applied wind)

1021 lbs = max hold down force factored

Elevation view

73.3 plf = diaphragm’s shear

121.0 plf = shearwall’sbase shear

3664 lbs = shear wall force

828 lbs = max drag strut force

456 lbs = anchorage force

Drag struts: calculations

73.3 x 4ft – 43.0 x 4ft = 121 lbs

4 ft 4ft 4ft 4ft 19ft

73.3 x 8ft – 43.0 x 4ft = 414 lbs73.3 x 12ft – 43.0 x 8ft = 535 lbs73.3 x 16ft – 43.0 x 8ft = 828 lbs

Drag struts: design

4 ft 4ft 4ft 4ft 19ft

Worst case in this wall 828 lbs, and usually is resisted by the double top plates. Must be able to resist both compression and tension

Drag struts: designWorst case in this wall 828 lbs, and usually is resisted by the double top plates. Must be able to resist both compression and tension

Use Sizer to calculate the compression and tension capacity of single top plate. Top plate often strong enough ‐ 2x4:

Pr = 10000 lbs (based on 24” lateral support)Tr = 6000 lbs

Use Connections to calculate the amount of fasteners required at the tension splice(min overlap 48”)



Shearwall schedule:

SHEARWALLS

Equations ‐ see .log file

SHEARWALLS

Equations ‐ see .log file

SHEARWALLS

Results in Word:

Wall Sheathing: Grade/ Fasteners Spacing

Grp Surf Material Ply Thk Or Bv Dia Len Pen

Edg Int Bk Jub #

1 Ext DF Plywood 3 7.5 Horz 4600 2.84 2 43 150 300 Y 1.0

1 Int GWB - 12.5 Horz 7005 - 1-1/2 26 200 300 Y 1.0 10

2 Both GWB - 12.5 Horz 7005 - 1-1/4 19 150 300 Y 1.0 10

3 Both GWB - 15.9 Horz 7005 - 2-1/4 41 150 300 Y 1.0 10

SHEATHING MATERIALS by WALL GROUP [mm]

Demo: JhdRemoving holddowns using anchorage• See p456 (WDM 2010) - WDM Final.wsw

• Demonstrate Jhd

Hold‐down Effect Factor Jhd

CSA O86 ‐ 9.4.5

Jhd basically states that the strength reduction is a function of ‐ the height of the shearwall, ‐ the lengths of the shearwalls, ‐ the overturning restraint force,‐ the basic shear capacity.



Hold-down Shearwall Segments Without Hold‐downs

Limitations:

• Max nail diameter 3.25 mm and min nail spacing 100 mm

• Maximum specified shear strength ‐ 10.3 kN/m

• Maximum shearwall height ‐ 3.6 m (12 ft.)

Note:

• Shear capacity reduced

• Complete load path

Shearwall Segments Without Hold‐downsDesign Based on Research by FPInnovations

• Overturning tension force is resisted by the sheathing

Applied ForceF

Tension Zone

• Nails resist overturning

Applied ForceF

Tension Zone

• Shear capacity is reduced

Applied ForceF

Tension Zone

CSA O86 ‐ 9.4.5Case 1‐ Jhd = 1 if hold‐downs are designed to resist all of the tension forces due to overturning

0.121

2

S

S

S

S

hd

ijhd L

H

L

H

V

PJ

Case 3‐ If a lower storey segment is held at the bottom but not the top, and there is uplift force at the top

0.1

hd

hdhd V

PVJ

Hold‐down Effect Factor Jhd

Case 2‐ if there are no hold downs at either end



JhdCase2: Jhd (there is no hold down, and Pij≥0)

Case3: Jhd (there is a hold down at the bottom of the panel and there is uplift force at the top

J 1 2P

VHL

HL

1

JV PV

1

Calculating upper storey Jhd

Roof dead load

Wall self weight

P21

J 1 2P

VHL

HL

1

Compare with software: Example compared with software: Level 2 Jhd and Vrs

Compare with software: Level 1 Jhd and Vrs

Demo: DeflectionDeflection calculation pages tables

Hold down database

Where to get the da (manufacturer tables)

What to add in addition to the da (crushing, shrinkage)

Show hold down tables with and without hold downs



Shearwall deflection

as

sns

s

s

ssw d

L

HeH

B

vH

LEA

vH 0025.0

3

2 3

Demo: Distribution• This example demonstrates a shearline construction that

would work for rigid, but not flexible. (ie capacity would be too low for flexible).

• Discuss that each shearwall could have 4 designs unless completely specified (best practise is to specify wall construction, no unknowns)

• Show relative rigidity “expression of stiffness”

• Deflection iterates to equate deflections of segments and sides of each segment, capacity doesn’t.

Example 1 is a typical 2800 sqft single family wood framed house. Source: SEAOC Vol 2 2006 IBC page 46

Distribute loads based on Flexible or Rigid Diaphragms?

Structural Engineering Association of California (SEAoC):“Structural Seismic Design Manual”

Example: Torsional moments, Rigid diaphragm

Torsional moment:

Calculate eccentricity (e):

Difference between• center of loading (mass) • center of resistance (rigidity).

The bigger “e” is the more torsional moment.

12.19m

1.22m

Centre of loading

9.14m 9.14m

e

Centre of resistance

Center of Load:Starting with flexible diaphragm distribution, locate the center of load.

Flexible distribution allows a preliminary calculation of capacities of wall segments (capacity / unit length).

Centre of loading

Flexible distrib = 6.6 kN

Flexible distrib = 6.6 kN

Seismic load = 13.2 kN

9.14/2m



Center of resistance:Length x capacity per unit length = strength = kStrength x moment arm = effect of strength, locations= ky

Length “capacity” k y ky12.19m x 2.59 = 31.54 x 0 = 01.22m x 5.92 = 7.22 x 9.14 = 66.0Sum 38.8 66.0

Center of resistance= 66.0 / 38.8= 1.70m


12.19m, 2.59 kN/m

1.22m, 5.92kN/m 9.14m

1.70m

Centre of loading

e= 9.14/2 – 1.70m = 2.87m

Eccentricity e= 2.87m


9.14m

Direct Shear based on shear line rigidity

Direct Shear Vd = Seismic load x “relative rigidity”

Seismic lo`ad = 13.2 kN

Vd (81%) = 10.7kN

Vd (19%) = 2.5kN

Length capacity k12.19m x 2.59 = 31.54 31.5 /38.8 = 81%1.22m x 5.92 = 7.22 7.2 /38.8 = 19%Sum 38.8 4.1.8.11. Equivalent Static Force Procedure for Structures

Satisfying the Conditions of Article 4.1.8.6.

(10): Torsional effects shall be accounted for… … by applying torsional moments about a vertical axis at each level throughout the building derived for each of the following load cases considered separately,

(i) Tx = Fx(ex + 0.10 Dnx), and(ii) Tx = Fx(ex – 0.10 Dnx)

Direct Shear needs to be amplified by the torsional effect

Accidental eccentricity =10% of building width

= 0.914m

Torsional moments= Direct load x e = 13.2 x (2.87 +/‐10% x 9.14) = 49.9 kNm (max)= 37.8 kNm (without accid)= 25.8 kNm (min)

Torsional moment= Direct load x (eccentricity + accidental)

Centre of loading

e

9.14m


Calculation of J, accounts for the relative rigidity in both directions and the distance of the walls from the center of resistance. k dy k dy2

31.54 ‐1.7 917.22 +7.44 400

Σ491

k dx k dx2

22.16 ‐6.1 82522.16 +6.1 825Σ13.2 Σ1650

k = 31.54

k = 7.22

9.14m

‐1.7m

+7.44mk = 22.16

k = 22.16

J = polar moment of inertia

J = ∑ k * d2

J = 491 + 1650 = 2141

12.19m




FLEX: 6.6RIGID: Direct 2.5 + Torsion 1.2

RIGID: Total 3.7 kN

Torsional force= MT x kd / ∑ kd= Torsional moment x relative rigidity x distance to the wall / J

FLEX: 6.6RIGID: Direct 10.7 + Torsion (‐0.6)

RIGID: Total 10.1 kN

Settings: shearwallrigidity

4 distribution methods for rigid diaphragm distribution

Stiffness (Deflection) distribution

Equal deflections

Capacity distribution

Equal capacities, deflections not equal

Connections



SHEARWALLS

CONNECTIONS

SIZERGravity Design


Fasteners

Concept mode


DATABASE EDITOR

since 1993/1994

since 1998/2000

since 1995/2000

Canada/US



• Beam to Beam

• Beam to column

• Column to base

• Wood to wood, concrete or steel

P

P

P

P

CONNECTIONS

CONNECTIONS

Connections and associated Fasteners on first screen

CONNECTIONSDetails are all displayed in one view

• Fully dimensioned CAD-like drawings• Some connections export as .dxf

CONNECTIONS

Beam to beam

Some connections export as .dxf

Beam to beam



Bolts 10.4

Wood Screws 10.11

CONNECTIONS Bolt Design 2009 CSA O86Parallel-to-

grain

Brittle

Perpendicular-to-grain

All loading directions

Bolt Yielding

Source: FP Innovations - Forintek

Bolt Design 2009 CSA O86 Yielding

Bolt Yielding

Mode gMode c Mode d

Source: Université Laval, 2009

Row Shear




Bolt Design 2009 CSA O86Row Shear

aL

SR

Group Tear-Out


Bolt Design 2009 CSA O86Group Tear-Out Perpendicular to Grain

Splitting


Bolt Design 2009 CSA O86Perpendicular to Grain Splitting

de

d

ep

Bolted Connection Detailing Observations

• Long end distance and narrow spacing in-row does not help with row shear design

• Increasing the number of bolts in a row could change the failure mode from row shear to group tear-out

• Splitting resistance is sensitive to the effective depth



Brittle failure possible

Ductile failuregoverns

Purchase online:

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Design Office: $895Sizer: $295

Discounts for multi-seat purchasesDiscounts for upgrades

($805) ($266)

robert jonkman, p.eng. - wood-works material, span details bearing ... provided that the maximum...

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