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Copyright © American Wood Council 1
Designing with AWC’s 2012 National Design Specification® (NDS®) for Wood ConstructionJohn “Buddy” Showalter, PEVice President, Technology TransferAmerican Wood Council
Michelle Kam-Biron, PE, SE, SECBDirector of EducationAmerican Wood Council
This presentation is protected by US and International Copyright laws Reproduction
Copyright Material
International Copyright laws. Reproduction, distribution, display and use of the presentation
without written permission is prohibited.
© American Wood Council 2014
Copyright © American Wood Council 2
Description
AWC's National Design Specification (NDS) for WoodConstruction 2012 is the dual format Allowable StressConstruction 2012 is the dual format Allowable StressDesign (ASD) and Load and Resistance Factor Design(LRFD) document referenced in US building codes andused to design wood structures worldwide. Participants willlearn about changes in the 2012 NDS and Supplementrelative to previous editions and gain an overview of thestandardstandard.
Learning Objectives
On completion of this course, participants will:
• Be able to understand Load and Resistance Factor Design• Be able to understand Load and Resistance Factor Design (LRFD) and how it applies to wood structural design.
• Be familiar with the significant changes between the 2005 and 2012 NDS and supplement.
• Be able to identify the similarities and differences with respect to ASD, design values, and behavioral equations
• Be able to analyze format and content within the 2012 e ab e to a a y e o at a d co te t t t e 0NDS.
Copyright © American Wood Council 3
Polling Question
1. What is your profession?
a) Architect
b) Engineer
c) Code Official
d) Building Designer
e) Other
Outline
• Overview• LRFD Primer• LRFD Primer • NDS
• Chapter-by-chapter discussion
• Changes from previous editions
• Summary
M I f• More Info.
Copyright © American Wood Council 4
Outline
• Overview • LRFD Primer• LRFD Primer• NDS
• Chapter-by-chapter discussion
• Changes from previous editions
• Summary
M I f• More Info.
NDS History
1944 1973 1991
1962
1968
1977
1982
1997
2001
1971 1986 2005
Copyright © American Wood Council 5
NDS History
International Building Code
• SECTION 2306 ALLOWABLE STRESS DESIGN
2306 1 Allowable stress design The structural• 2306.1 Allowable stress design. The structural analysis and construction of wood elements in structures using allowable stress design shall be in accordance with the following applicable standards:
• American Forest & Paper Association.
• NDS National Design Specification for Wood Constructionfor Wood Construction
• 2307.1 Load and resistance factor design.
• The structural analysis and construction of wood elements and structures using load and resistance factor design shall be in accordance with AF&PA NDS.
Copyright © American Wood Council 6
NDS and Supplement
• 2005• 16 Chapters• 16 Chapters• 14 Appendices
NDS 2012 Approval
• ANSI approval
• August 15, 2011
• 2012 IBC Reference
Copyright © American Wood Council 7
NDS and Supplement
2012• 16 Chapters• 14 Appendices
2005• 16 Chapters• 14 Appendices
Wood Design Package
2005 Wood Design Package
2012 Wood Design Package
Copyright © American Wood Council 8
Addenda/Errata
• Publications Addenda/Errata
• Comprehensive List
• http://awc org/publications/update/index html• http://awc.org/publications/update/index.html
• Free download
Outline
• Overview • LRFD Primer• LRFD Primer• NDS
• Chapter-by-chapter discussion
• Changes from previous editions
• Summary
M I f• More Info.
Copyright © American Wood Council 9
Design Process
Demand Capacity
Design Process
LoadSupport Conditions DemandDemandSupport ConditionsGeometryMaterialsMaterialsPerformancePerformanceFireEconomics
DemandDemand
CapacityCapacity
EconomicsAesthetics….
Copyright © American Wood Council 10
Design Concepts
Two Limit State concerns:
• Serviceability (performance in-service)
• Safety against failure or collapse
Serviceability
• Unfactored loads• Mean (avg) material strength values
Copyright © American Wood Council 11
LRFD - Safety
• Factored loads• Material strengthMaterial strength values - modified
xx = standard deviation
x
xx = mean
SCL
Structural Property VariabilityNormal Distribution Curves
COVx =x
x
Vi ll G d dVi ll G d d
MSR Lumber
Glulam
I-Joist
SCL
Load
Rel
ativ
e F
req
uen
cy
Coefficient of variation
Material Property Values
Visually Graded Visually Graded LumberLumber
R
Copyright © American Wood Council 12
Engineered Wood Design
S > RFailure
Statistical Model
• Normal Distribution Curves for Safety Function, Z
fZ = fR - fS
22SRz
mZ = mR - mS
Probability of
Safety (or reliability ) Index
z
zm
Probability of failure of structure
Performance Distribution (Z)
Copyright © American Wood Council 13
Probability of Failure
• Pf = one failure expected for x number
Pfof structures designed and built with a given
• Safety (or reliability index) Ex. = 3.2 represents 1 failure for every 1 000 structures
Pf
5.2 1 : 10,000,000
4.7 1 : 1,000,000
4.2 1 : 100,000
3.7 1 : 10,000
3.2 1 : 1,000
2.7 1 : 100 every 1,000 structures or members designed.
2.2 1 : 10
LRFD - Range on
• Structural Design • Range for Strength Various Materials• Range for Strength Various Materials
Low Typical High 2.4 2.6 2.9 Pf 1 : 25 1 : 63 1 : 251
Copyright © American Wood Council 14
LRFD Design Equation
Demand Capacityp y
Q Q RRnn
n
i=1
b b = = Safety or Reliability Index = = Load Factor = = Reliability Index == Time effect factor (replaces LDF)
Allowable Stress Design
• What stays the same?• Same basic equation format• Same basic equation format• Same adjustment factors• Same behavioral equations
Copyright © American Wood Council 15
LRFD vs. ASD
• Three new notations - , , and KF• Design loads (factored) for safety are g ( ) y
bigger• Design loads (unfactored) for
serviceability are the same• Material resistance values
are biggerd h• Load Duration Factor changes
to Time Effect Factor
LRFD vs. ASD
Theoretical safety
•ASD•applied stress allowable stress
Theoretical safety margin applied to material stresses
Tested material strengthEstimated
LoadsDesign Load
Adjusted Resistance
Design values
Copyright © American Wood Council 16
LRFD vs. ASD
•LRFD•factored load factored resistance
Member performance factorfactor
Load factors to account for variations in loads
Tested member resistance
Estimated loads
Factored Design Load
Factored Design Resistance
Design values
2012 NDS
• Factored Load Combinations ASCE 7-10
Copyright © American Wood Council 17
•Format Conversion Factor KF:
NDS 2012 LRFD Specification
R C RRN = CDRASDASD
RN = KF RASD
LRFD
RASD reference strengths
2012 NDS
Reliability indices or data confidence factors
Copyright © American Wood Council 18
• tied to ASCE 7 Factored Loads:
2012 NDSBaseline 10 minutes (ASD uses 10 years)
Long term
Permanent
Short term
2012 NDS
RN = KF RASD
KF converts reference design values (ASD normal load duration) to LRFD reference resistance
Copyright © American Wood Council 19
Why use LRFD?
• Ease of designing with multiple materials
• Does not penalize material strength for unknowns on loads
• Realize efficiencies with
• Multiple transient live loads
• Extreme event loads
• ASD load combinations have notASD load combinations have not been maintained in deference to LRFD load combinations
Polling Question
2. Format Conversion Factor, KFa) is only used with ASD
b) is not necessary when calculating shear strengthb) is not necessary when calculating shear strength using LRFD
c) converts ASD material reference design values from the 2012 NDS Supplement for use with LRFD
d) converts LRFD material reference design values from the 2012 NDS Supplement for use with ASD
Copyright © American Wood Council 20
Outline
• Overview • LRFD Primer• LRFD Primer• NDS
• Chapter-by-chapter discussion
• Changes from previous editions
• Summary
M I f• More Info.
NDS 2012 Chapters1. General Requirements for Building Design2. Design Values for Structural Members3. Design Provisions and Equations4. Sawn LumberSa u be5. Structural Glued Laminated Timber6. Round Timber Poles and Piles7. Prefabricated Wood I-Joists8. Structural Composite Lumber9. Wood Structural Panels10. Mechanical Connections11. Dowel-Type Fasteners12. Split Ring and Shear Plate Connectors13. Timber Rivets14. Shear Walls and Diaphragms15. Special Loading Conditions16. Fire Design of Wood Members
Commentary!!!
Copyright © American Wood Council 21
NDS 2012 Supplement
1. Sawn Lumber Grading Agencies2. Species Combinations3. Section Properties4. Reference Design Values
• Lumber and Timber• Non-North American Sawn
LumberStructural Glued Laminated• Structural Glued Laminated Timber
• MSR and MEL• Timber Poles and Piles
A. Construction and Design PracticesB. Load Duration (ASD Only)C. Temperature EffectsD. Lateral Stability of BeamsE L l St i F t G
NDS 2012 Appendices
E. Local Stresses in Fastener GroupsF. Design for Creep and Critical Deflection
ApplicationsG. Effective Column LengthH. Lateral Stability of ColumnsI. Yield Limit Equations for ConnectionsJ. Solution of Hankinson EquationK. Typical Dimensions for Split Ring and Shear
Plate ConnectorsL Typical Dimensions for Standard Hex BoltsL. Typical Dimensions for Standard Hex Bolts,
Hex Lag Screws, Wood Screws, Common, Box, and Sinker Nails
M. Manufacturing Tolerances for Rivets and Steel Side Plates for Timber Rivet Connections
N. Appendix for Load and Resistance Factor Design (LRFD) – Mandatory
Copyright © American Wood Council 22
NDS – Chapter 1
Chapter 1 - Terminology
fb ≤ Fb'
Reference design values (Fb, Ft, Fv, Fc, Fc, E, Emin)
Adjusted design values (Fb', Ft', Fv', Fc', Fc', E', Emin')Allowable (changed in the 2005)
Copyright © American Wood Council 23
Chapter 1 – Design Loads
• Reference loads
Minimum load standards• Minimum load standards
• ASCE 7 – 10
NDS – Chapter 2
Copyright © American Wood Council 24
Chapter 2 – Adjustment Factors
Reliability indices or data confidence factors
tied to ASCE 7 Factored Loads: Baseline 10 minutes (ASD uses 10 years)
Appendix N – Adjustment Factors
Sh t t
Long term
Permanent
Short term
Copyright © American Wood Council 25
Chapter 2 – Adjustment Factors
Revised ASTM D5457-10
RN = KF RASD
KF converts reference design values (ASD normal load duration) to LRFD reference resistance
Chapter 2 – Adjustment Factors
• Adjusts from reference to site conditions• CD time-dependentCD t e depe de t
Baseline 10 years
Copyright © American Wood Council 26
Chapter 2 – Adjustment Factors
• Adjusts from reference to site conditions• Ct temperature factorCt te pe atu e acto
Exposed for “sustained” period
Chapter 2 – Adjustment Factors
• Wet Service Factor, CM
Copyright © American Wood Council 27
Wet Service Conditions
25
30
%
0
5
10
15
20
Wo
od
EM
C %
Temp 30 deg F
Temp 70 deg F
Temp 130 deg F
0 20 40 60 80 100
Relative Humidity %
100
110
e C
on
ten
t
Wet Service Conditions
40
50
60
70
80
90
%S
tre
ng
th a
t 1
2%
Mo
istu
re
Impact Strength
Modulus of Elasticity
Modulus of Rupture
Crushing Strength
40
12 14 16 18 20 22 24 26 28 30
Moisture Content of Wood (%)
%
Copyright © American Wood Council 28
Wet Service Factor, CM
• Sawn lumber MC < 19% considered dry• Otherwise, NDS Supplement for lumberOtherwise, NDS Supplement for lumber
Polling Question3. Temperature Factor Ct applies to conditions
where the wood temperatures exceed:a) 100 degrees F for sustained periods of timea) 100 degrees F for sustained periods of time
b) 100 degrees F for short period of time
c) 100 degrees F at any time
d) 100 degrees C at any time
Copyright © American Wood Council 29
NDS – Chapter 3
Chapter 3 – Behavioral Equations
ASD vs LRFD – adjusted stresses from reference
• ASD F′n = Fn CD x adjustment factors
• LRFD F′n = Fn KF n x adjustment factors
Copyright © American Wood Council 30
Chapter 3 – Behavioral Equations
• Beams • CL beam stabilityy
•
Critical Buckling Design Value for bending members
Chapter 3 – Behavioral Equations
• Beams
FbE Equivalence
• Emin adjusted for safety for both ASD and LRFD processes
RB Slende ness Ratio
2b
'bE
2b
'min
bE REK
RE20.1F
2012/2005 NDS
2001 NDS
• RB = Slenderness Ratio
Copyright © American Wood Council 31
Chapter 3 – Behavioral Equations
• Columns• CP column stability
Critical Buckling Design Value for compression members
Chapter 3 – Behavioral Equations• Columns
• FcE equivalence
2e
'cE
2e
'min
cE
dl
EK
dl
E822.0F
2001 NDS
2012/2005 NDS
Copyright © American Wood Council 32
Chapter 3 – Behavioral Equations
66.1/))(645.11(03.1min ECOVEE E = reference MOE
OREmin values published in NDS Supplement
E = reference MOE1.03 = adjustment factor to convert E to a pure bending
basis (shear-free) (use 1.05 for glulam)1.66 = factor of safetyCOVE = coefficient of variation in MOE (NDS Appendix F)
Chapter 3 – Behavioral Equations
Tension members (tension parallel to grain)
• ASD F′t = Ft CD x adjustment factors
• LRFD F′t = Ft KF t x adjustment factors
Copyright © American Wood Council 33
Chapter 3 – Behavioral Equations
• Wood and tension perpendicular to grain
• Not recommended per NDS 3.8.2
initiators:• notches
• moment connections
• hanging loads
Chapter 3 – Behavioral Equations
• Combined bi-axial bending and axial compression
Copyright © American Wood Council 34
• Combined bi-axial bending and axial compression
Chapter 3 – Behavioral Equations
New
Added to account for possible negative value in denonimator of third term of equation 3.9-3
Chapter 3 – Behavioral Equations
• Bearing perpendicular to grain• F′c = Fc CM Ct Ci Cb (ASD)c c M t i b
• F′c = Fc CM Ct Ci Cb Kf c (LRFD)
Copyright © American Wood Council 35
NDS – Chapter 4
Chapter 4 – Lumber
•Design valuesVisually graded lumber• Visually graded lumber
• MSR / MEL
• Timber
• Decking
Copyright © American Wood Council 36
Chapter 4 – Lumber
•Lumber adjustmentadjustment factors• KF and
Chapter 4 – Lumber
•Lumber adjustmentadjustment factors• KF and
Copyright © American Wood Council 37
Chapter 4 – Lumber• Lumber adjustment factors
• CF - size factor
Chapter 4 – Lumber• Lumber adjustment factors
Copyright © American Wood Council 38
Chapter 4 – Lumber
• Lumber adjustment factors
• repetitive member
• Cr = 1.15
• 2” – 4” lumber
• < 24” o.c.
• 3 or more
• Load distributingLoad distributing
element
NDS – Chapter 5
Copyright © American Wood Council 39
• Significant changes
• New adjustment factors
St i t ti
Chapter 5 – Glulam
• Stress interaction
• Shear reduction
• Clarified or added
• Curved members
• Double-taperedp
• Tapered straight
Chapter 5 – Glulam
• New adjustment factors
• Stress interactiond• Tapered
• Timber Construction
manual
• Shear reduction• NDS footnote• Non-prismaticNon-prismatic
Copyright © American Wood Council 40
Chapter 5 – Glulam
• Clarified or added
• Curved membersCurved members
• Double-tapered
• Tapered straight
Chapter 5 – Glulam
• Adjustment factors
• CV Volume Factor
C B St bilit F t• CL Beam Stability Factor
• Not cumulative with CL
• Min (Cv, CL)
Copyright © American Wood Council 41
Polling Question4. The two new adjustment factors were added
to glued laminated timber design are stress interaction and shear reduction factors. T/Finteraction and shear reduction factors. T/F
True
NDS – Chapter 6
Copyright © American Wood Council 42
Chapter 6 – Poles & Piles
• Poles - post-framePil f d ti• Piles - foundations
Chapter 6 – Timber Piles• Design values
• Significant changes from 2005 NDS
Design values moved to NDS Supplement• Design values moved to NDS Supplement
2005 NDS
2012 NDS
Copyright © American Wood Council 43
Chapter 6 – Timber Poles
2005 NDS
2012 NDS
Chapter 6 – Poles & Piles
• Adjustment factors
• Cct – condition treatment
• Cls – load sharing
• Ccs – critical section
Copyright © American Wood Council 44
NDS – Chapter 7
Chapter 7 – I-joists
• Design values
• M, V, EI, K – no changes
• Evaluation Reports
• Contain proprietary design
Copyright © American Wood Council 45
Chapter 7 – I-Joists
•Beam stability factor
• Braced compression flangeBraced compression flange
• CL = 1.0
• Unbraced compression flange
• Design as unbraced column
NDS – Chapter 8
Copyright © American Wood Council 46
Chapter 8 – Structural Composite Lumber
• No changes from 2005 NDS• Evaluation Reports
Contain proprietary design
x
x = mean
COVx =xx
MSR Lumber
Glulam
I-JoistSCL
ativ
e F
req
uen
cy
• Contain proprietary design
Material Property Values
Visually Graded Visually Graded LumberLumber
Load
Rel
a
Chapter 8 – Structural Composite Lumber
• Adjustment factors
• CV – volumeC 1 0 N l i i h b bili f C h i (C C )Cv < 1.0 Not cumulative with beam stability factor, CL - then min. (Cv, CL)
Cv > 1.0 Cumulative with beam stability factor, CL
Copyright © American Wood Council 47
Chapter 8 – Structural Composite Lumber
• Adjustment factors
• C Repetitive Member Factor= 1 04Cr Repetitive Member Factor 1.04• Cr is different than lumber (Cr lumber = 1.15)
• Applies to Fb only
NDS – Chapter 9
Copyright © American Wood Council 48
Chapter 9 – Wood Structural Panels
• Design values – obtain from an approved source
• FbSb
• FtA
• Fvtv
• Fs
• FcA
EI• EI
• EA
• Gvtv
• Fc
Chapter 9 – Wood Structural Panels
• Adjustment factors apply Fb & Ft
• CG - grade & construction
• Removed (no longer used by wsp industry)
• Cs - panel size
• Clarified
• Moved from commentary
Copyright © American Wood Council 49
Chapter 9 – Wood Structural Panels
• Adjustment factors
• CM - wet serviceCM wet service
• Ct - temperature
NDS – Chapter 10
Copyright © American Wood Council 50
Chapter 10 – Mechanical Connections
• Design issues
• Reference design values
Ch t 11 d l t t ( il b lt l / d )• Chapter 11 – dowel-type connectors (nails, bolts, lag/wood screws)
• Chapter 12 – split rings and shear plates
• Chapter 13 – timber rivets
• Adjustment factors
• No significant changes
Connections session• Connections session
NDS – Chapter 11
Copyright © American Wood Council 51
Chapter 11 - Tabulated Values• Consistent titles and footnotes• Penetration assumptions in titles
Chapter 11-Dowels
Copyright © American Wood Council 53
Chapter 11-Dowels
Threaded length < lm/4 lm
Dia. Fastener = D
Dia. Fastener = D
Threaded length < lm/4
lm
Chapter 11-Dowels
lm
Dia. Fastener = Dr
Copyright © American Wood Council 54
Chapter 11 - Dowels
Provide tools for the analysis• gaps between members• gaps between members• various fastener moment resistance
configurations• fasteners through hollow members• fasteners with tapered tips
http://www.awc.org/publications/TR/index.php
Chapter 11 - Tabulated Values
• New post frame ring shank tables• Based on ASTM F1667
Copyright © American Wood Council 55
Chapter 11 - Dowel Bearing Length
Fastener Type Tip Length, E
Lag Screws Appendix LLag Screws Appendix L
Wood Screws 2D
Nails & Spikes 2D
E, ℓs, ℓm < p – E / 2, s, m p /
Chapter 11 - Dowel Bearing Strength • Wood Structural Panels
• D < ¼
Copyright © American Wood Council 56
Chapter 11 - Perp to Grain Distance
• Glulam only
• Moisture content
• Glulam only
• Moisture content
Polling Question
5. TR 12 includes general dowel equations and provides tools for the analysis of:
a) gaps between membersa) gaps between members
b) fasteners through hollow members
c) fasteners with tapered tips
d) All of the above
e) None of the above
Copyright © American Wood Council 57
NDS – Chapter 12
Chapter 12 – Split Rings and Shear Plates
• Geometry factor, CD
• Side Grain
Copyright © American Wood Council 58
Chapter 12 – Split Rings and Shear Plates
• Geometry factor, CD
• End Grain
NDS – Chapter 13
Copyright © American Wood Council 59
Chapter 13 – Timber Rivets
• Many applications
Chapter 13 – Timber Rivets
Copyright © American Wood Council 60
Chapter 13 – Timber Rivets
• Parallel to grain
• Timber rivet capacity
• Proper application of CD
Timber Rivets – Design 2005 NDS
Copyright © American Wood Council 61
Timber Rivets – Design 2012 NDS
Chapter 13 – Timber Rivets• Timber rivet capacity
• Proper application of CD
Parallel to grain timber rivet capacity• Parallel to grain timber rivet capacity
• Pr = 280 p0.32 nR nC (13.2-1)
• Perpendicular to grain timber rivet capacity
• Qr = 160 p0.32 nR nC
188 2012 NDS
108 2012 NDS
Copyright © American Wood Council 62
Chapter 13 – Timber Rivets
• Maximum distance perpendicular to grain between outermost rows of rivets shall be 12
• Consistent with glulam
NDS – Chapter 14
Copyright © American Wood Council 63
NDS – Chapter 14
• ANSI / AWC SDPWS
2008 standard
Chapter 14 – Shear Walls and Diaphragms
• Recorded Webinar
•Online course 2005/2008
SDPWS
•Diaphragm Deflection
•www.awc.org
Copyright © American Wood Council 64
NDS – Chapter 15
Chapter 15 – Special Loading
• Built-up columns
• Flatwise bending check
• Consistent with Chapter 3
New
Copyright © American Wood Council 65
NDS – Chapter 16
Chapter 16 – Fire (ASD)• Fire resistance up to two hours
• Columns• Beams
T i M b
…
• Tension Members• ASD only
• Products• Lumber• Glulam• SCL
D ki• Decking
Copyright © American Wood Council 66
Chapter 16 – Calculated Resistance
• Fire resistance of exposed wood members may be calculated usingmay be calculated using the provisions of NDS Chapter 16
Fire Resistance
Glulam SteelGlulam Steel
Copyright © American Wood Council 67
Performance of Wood vs. Steel
T h i l R t N 10
Chapter 16 – Fire (ASD)
Technical Report No. 10
Copyright © American Wood Council 68
Code Updates -Design of Fire
Chapter 16 – Fire (ASD)
Design of Fire-Resistive Exposed Wood Members
http://www.awc.org/publications/download phpblications/download.php
Polling Question
6. The IBC includes provisions for calculating fire resistance of exposed wood members and wood decking for up to two hoursand wood decking for up to two hours. True/False
True
Copyright © American Wood Council 69
NDS – Appendices
2012A Construction and Design PracticesB Load DurationC Temperature EffectsD Lateral Stability of Beams
NDS 2012 Appendices
ate a Stab ty o ea sE Local Stresses in Fastener GroupsF Design for Creep and Critical Deflection
ApplicationsG Effective Column LengthH Lateral Stability of ColumnsI Yield Limit Equations for ConnectionsJ Solution of Hankinson EquationK Typical Dimensions for Split Ring and
Shear Plate Connectorsi l i i f d dL Typical Dimensions for Standard Hex
Bolts, Hex Lag Screws, Wood Screws, Common, Box, and Sinker Nails
M Manufacturing Tolerances for Rivets and Steel Side Plates for Timber Rivet Connections
N Appendix for Load and Resistance Factor Design (LRFD)
Copyright © American Wood Council 70
Appendix E
• Example E.8• Acritical checkAcritical check
Appendix L
Copyright © American Wood Council 72
Outline
• Overview• LRFD Primer • NDS
• Chapter-by-chapter discussion
• Changes from previous editionsSummary• Summary
• More Info.
2012 NDS – Notable Changes
• Chapter 5 – GlulamChapter 6 Poles and Piles• Chapter 6 – Poles and Piles
• Chapter 12 – Split Rings & Shear Plates
Copyright © American Wood Council 73
NDS 2012 Supplement
• New nominal and minimum Timber sizes per PS 20-10
• Section properties distinguish lumber, P&T, B&S
• New Coast Sitka Spruce & Yellow Cedar values
• Revised Northern Species bending and tension values
• Clarify Timber size factor adjustments
• New and revised values for several foreign species
• Revised glulam values - primary changes to shear
• New Tables 6A & 6B for Timber Poles and Piles
Southern Pine Design Values
• ALSC approves design values
• June 1, 2013
• AWC compiles them
• NDS Supplement
• More information
• www.spib.org
• www.southernpine.com
Copyright © American Wood Council 74
Wood Design Package
• Wood Design Package
• NDS + Commentary
MANUAL
Supplement: Design Values for Wood Construction
• NDS Supplement
• ASD/LRFD Manual
• Example Problems
• Almost complete
MANUAL
Future
2015
Copyright © American Wood Council 75
Coming in 2015 NDS/SDPWS
• NDS
• CLT Provisions
Franklin Elementary School
Franklin, West VirginiaArchitect: MSES Architects, Fairmont, WV Source: LignaTerra
Copyright © American Wood Council 76
Franklin Elementary School
Franklin, West Virginia46,200 sq. ft.8 week assembly
Source: LignaTerra
Franklin Elementary School
Source: LignaTerra
Copyright © American Wood Council 77
Franklin Elementary School
Scheduled completion date: Winter 2015
Coming in 2015 NDS/SDPWS
• NDS
• CLT Provisions
• SDPWS
• Design Flexible and Open Front/Cantilever Diaphragms
Copyright © American Wood Council 78
2015 Special Design Provisions for Wind and Seismic
2015 SDPWS
Overview
• Ch. 2
• Removes definition of flexible and rigid diaphragms• Defines “Open-Front Structure” & “Subdiaphragm”
• Ch. 4
• Clarification of concrete and masonry wall anchorage• Revised Horizontal Distribution of Shear• Clarification of shear wall Aspect ratio adjustments
Copyright © American Wood Council 80
More Details
• White paper - www.awc.org
• Comprehensive table
• Section-by-section changes
• Structure Magazine• January 2012
Resources