National Design Specification for Wood Construction The Wood Products Council is a Registered Provider with. Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Presented by: Michelle Kam-Biron, PE, SE Director, Education Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Copyright Materials This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. American Wood Council 2012 Learning Objectives At the end of this program, participants will be knowledgeable of:
1991 1944 1973 1997 1962 1977 2001 1968 1982 2005 1971 1986 2012
http://www.awc.org/standards/sdpws. html
Demand Capacity
Relative Frequency x = mean x = standard deviation x COV x = x Load x x x SCL I-Joist Glulam MSR Lumber Visually Graded Lumber Material Property Values
f Z = f R -f S m Z = m R -m S z 2 R 2 S m z z x P f 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 2.2 1 : 10 Low Typical High 2.4 2.6 2.9 P f 1 : 25 1 : 63 1 : 251
n Q R n i=1 = Load Factor = Reliability Index = time effect factor (replaces LDF) Estimated loads Design Load Theoretical safety margin applied to material stresses Adjusted Resistance Tested material strength
Member performance factor Load factors to account for variations in loads Estimated loads Factored Design Load Factored Design Resistance Tested member resistance
ASD load combinations have not been maintained in deference to LRFD load combinations
1. General Requirements for Building Design 2. Design Values for Structural Members 3. Design Provisions and Equations 4. Sawn Lumber 5. Structural Glued Laminated Timber 6. Round Timber Poles and Piles 7. Prefabricated Wood I-Joists 8. Structural Composite Lumber 9. Wood Structural Panels 10. Mechanical Connections 11. Dowel-Type Fasteners 12. Split Ring and Shear Plate Connectors 13. Timber Rivets 14. Shear Walls and Diaphragms 15. Special Loading Conditions 16. Fire Design of Wood Members Commentary!!! A. Construction and Design Practices B. Load Duration (ASD Only) C. Temperature Effects D. Lateral Stability of Beams E. Local Stresses in Fastener Groups F. Design for Creep and Critical Deflection Applications G. Effective Column Length H. Lateral Stability of Columns I. Yield Limit Equations for Connections J. Solution of Hankinson Equation K. Typical Dimensions for Split Ring and Shear Plate Connectors L. 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 1 Sawn Lumber Grading Agencies 2 Species Combinations 3 Section Properties 4 Reference Design Values - Lumber and Timber (In service < 19% MC) -Non-North American Sawn Lumber -Structural Glued Laminated Timber (In service < 16% MC) -MSR and MEL -Round Timber Piles and Poles
Wood EMC % 30 25 20 15 10 5 0 0 20 40 60 80 100 Temp 30 deg F Temp 70 deg F Temp 130 deg F %Strength at 12% Moisture Content 110 100 90 80 70 60 50 40 12 14 16 18 20 22 24 26 28 30 Impact Strength Modulus of Elasticity Modulus of Rupture Crushing Strength Relative Humidity % Moisture Content of Wood (%)
initiators: notches moment connections hanging loads
Relative Frequency x = mean COV x x = x Load x SCL I-Joist Glulam MSR Lumber Visually Graded Lumber Material Property Values
DCA 2 Design of Fire-Resistive Exposed Wood Members Limited to 1-Hour IBC 721.6.1.1 Simplified approach Beams/Columns
2012 A Construction and Design Practices B Load Duration C Temperature Effects D Lateral Stability of Beams E Local Stresses in Fastener Groups F Design for Creep and Critical Deflection Applications G Effective Column Length H Lateral Stability of Columns I Yield Limit Equations for Connections J Solution of Hankinson Equation K Typical Dimensions for Split Ring and Shear Plate Connectors L 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)
MANUAL
Questions?