Clt mtb seminar_presentation_four
- 1. Software solutions for LVL building systems Cameron Rodger B.Eng(Civil), MIEAust, MIPENZ, CPENG LVL Business Manager
- 2. Agenda • Laminated Veneer Lumber • Material Selection • LVL building design guidelines • Timber engineering design tools - computeIT Suite • Whangarei Dry Mill – a practical design example using computeIT toolkIT • I-beam purlin design • Box beam design • Solid rafter design • Practical considerations • Real examples • TCC Floor Design using computeIT for beams
- 3. Laminated Veneer Lumber (L.V.L) • CHH Engineered Wood Products range – Structural LVL – hyONE (E=16.0), hySPAN+ (E=14.0), hySPAN (E=13.2), hyCHORD (E=11.0), hy90(E=9.5), hyJOIST – Use higher grade LVL for primary structural members – Use i-beams or lower grade LVL for secondary framing • Features and benefits – Sourced from renewable plantation pine • Consistent quality raw material availability, carbon storing helping reduce green house gas omissions • Available FSC Certified – Manufacturing process 3rd party audited • Guaranteed consistent quality – Peeled veneer eliminating naturally occurring defects • Removes localised stress raisers such as knots, etc. • Veneer tested for stiffness and recipes established for each product
- 4. Structural L.V.L • LVL is an engineered material with the intrinsic benefits of timber • Suitable for use in fully integrated LVL systems including: – Built up LVL portal frame components – Composite plywood and LVL purlins – LVL wall framing – TCC Floors – Multi-Storey Structural Systems • Designers can have confidence that the design intent will carry through to the finished structure
- 5. LVL - Material selection LVL ideal material choice due to adaptability in: – Structural reliability/variability – Production lengths – Limitless (18.3 m practically) – Sections sawn from nominal 1200 mm billet – Thickness variation • Ranging from 28 mm to 105 mm – Type of LVL • Long band • Cross band – Allows for creation of built up sections • Box Beams • Deep I-beams
- 6. Portal Suite - Material selection • Cross Band LVL – Dimensional Stability. – Reduces tendency of long band veneers to split from fasteners – Limited stocks readily available, largely a made to order product
- 7. LVL Building design guidelines • Design methodology and loading – Design criteria based on structure type not material type – Loading in accordance with relevant loading standards – Footing and bracing design similar to steel systems • Footing sizes an have significant savings in relation to concrete buildings – Optimal member spans and bay/frame spacings may be different for timber, steel and concrete structural systems
- 8. LVL Building design guidelines • Elastic Structural Analysis (Microstran, Spacegass) differs little to that applied to steel except for structural properties • No separate consideration of shear deflection required for solid LVL sections – For built up sections adjustments to Poisons ratio required • A number of options for rigid moment resisting connections – X-banded LVL gussets – Quick connect jointing system – Post tension/pre-stressed structural systems • Serviceability limits similar to steel and concrete • Effects of creep need to be taken into account for permanent loads
- 9. Design Tools CHH have produced tools to aid in the design of LVL based systems • Software based solutions – computeIT for beams • Now includes TCC Floor Design – computeIT toolkIT • Rigid moment connection design • Member design (solid and built up sections) • Purlin Design • Girt Design – Includes Design details, commonly available products and connections • Alternate commercial product range • Engineering support from experienced consulting timber design engineers
- 10. computeIT Suite 1. Provides LVL Structural solutions for market segments currently limited to EWP’s through engineering design capability/costs 2. Make the design of timber based systems and connections as easy, or easier than steel alternatives 3. Presents proven, cost effective solutions from readily available LVL members 4. Developed by practicing timber design engineers for engineers 5. Interactive design in accordance with regulatory design standards 6. Design modules that aid engineers in the interpretation of timber phenomena 7. Still allows the design engineer to make the decision about the suitability of design
- 11. computeIT for beams An integrated design and analysis package for engineers. Aids engineers in the understanding of timber design and analysis. Target Market – All engineers (those not comfortable with ‘black box’ packages) currently using structural analysis packages and steel solutions – residential & commercial projects
- 12. computeIT for beams • Point of difference – Design & Analysis Package • Allows for entry of predetermined loads for beam designs for all types of loading for differing beam configurations • Design and analysis for both strength and serviceability limit states – Un-factored loads entered – Factored load cases presented as per AS/NZS 1170.1 – Users enter restraint condition – Design in accordance with AS1720 – Provides guidance for engineers in relation to timber phenomenon's » Shear Deflection » Creep » Duration of load – Importantly, still allows engineer to make the decision about the suitability of the section
- 13. computeIT for beams- Now includes EXPAN/STIC technology Timber Concrete Composite (TCC Floors) providing composite action between concrete and LVL structural elements. Key Value Proposition Provide a structurally fit for purpose solution that includes a level of fire resistance and acoustic attenuation.
- 14. computeIT toolkIT computeIT toolkit is a series of design tools to allow for the quick and easy design of rigid moment connections, primary and secondary members Target Market – engineers design commercial and industrial buildings
- 15. computeIT toolkIT Point of difference: – computeIT toolkit provides users with the opportunity to: • design moment resisting connections with commonly available materials and connectors • design solid and built up members subject to combined actions, easily considering the effects of alternate restraint options • Load combinations to AS/NZS 1170, with automatic selection of duration of load factor • analyse different members to determine cost effective options • design solid and i-beam purlins and girts, including support and restraint details • create a job specific Engineering Analysis Report including designed members and connections • Provides guidance for engineers in relation to timber phenomenon's – Direction of grain – Duration of load • Review full worked design examples to aid engineers with the adoption of timber engineering
- 16. computeIT toolkIT - Now includes EXPAN/STIC technology Quick Connect moment resisting connection design technology is now included in computeIT toolkIT. Key Value Proposition The quick connect technology uses a threaded rod, washers and nuts for ease of connection on site through factory fitted LVL sleeves.
- 17. computeIT for PORTAL FRAMES – under development computeIT for PORTAL FRAMES is a fully integrated design, detailing, specification, and takeoff package for the design of LVL based portal frames Target Market – engineers designing portal frame systems - fabricators (costing and fabrication)
- 19. Whangarei Dry Mill – A practical design example • A practical engineering approach including: – Use of box and solid sections – I-beam purlin design options – Optimisation of material usage (and cost) • Fabrication – Importance of using an experienced fabricator • Peace of mind • Kit-set delivery – Large solid section vs lower volume built up section • Erection methodology – Bay lifts • Program advantages • OH&S advantages
- 20. Whangarei Dry Mill • Cost effective and structurally efficient design to develop a 12,210 m2 building • Member selection based on: – Structural integrity, – Material availably, and – Level of fabrication expertise required • Versatility of LVL allowed development of a frame with: – Built up box beams that have cross banded (x-band) LVL webs and LVL flanges in high moment regions – 18.2 m long solid 105 mm thick LVL sections in reduced moment regions, reducing fabrication time and cost. – Off the shelf I-beam purlins at 10 m bays completed the large manufacturing and storage facility.
- 21. Whangarei Dry Mill – Building footprint
- 22. Whangarei Dry Mill – Elevations Two portal frames proposed to share ridge line
- 25. Whangarei Dry Mill – Purlin Layout
- 26. Whangarei Dry Mill – Purlin Design 1. Reduced spacing – Increased number of components – More on site connections 2. Increase flange size/capacity as required – Typical for large buildings – Eliminates multiple spacing adjustments – Capability to manufacture ‘specifically designed’ I beams. 3. Increase number of lateral restraints Solution : Mixture of reduced spacing and increased flange size provides optimum design solution Purlins within proximity of building edge subject to localised pressure & require:
- 27. I-beam Purlin Design Region Within ‘a’ from windward edge Within ‘h’ from windward edge Span 10000-193 = 9807 10000-105 = 9895 Spacing (max) 1380 1600 Roof Mass Roof sheeting mass 6.5 kg/m2 6.5 kg/m2 Miscellaneous 2.0 kg/m2 2.0 kg/m2 Wind Loading weff -1.74 kN/m/m# -1.10 kN/m/m# R* -8.36 kN/m# -5.45 kN/m# weff +0.85 kN/m/m# +0.85 kN/m/m# R* +4.25 kN/m# +4.25 kN/m# #Loads/Design action effects per metre load width
- 28. Whangarei Dry Mill – Portal Frame Design • Points of contraflexure define component length & splice locations • Sections developed relative to suitability to resist required design actions – Bending, Axial and Shear forces – Relative stiffness controls moment distribution
- 29. Whangarei Dry Mill – Portal Frame Design • Reduced rigidity draws less moment to sections • Ease of in-situ splice with box sections • Ease of fabrication • Section kept to depth to breadth ratio of 10 • Flybraces provide lateral restraint Solid 1050x105 LVL section chosen for lower moment region
- 30. Whangarei Dry Mill – Portal Frame Design Box sections chosen for higher moment regions • Hollow section optimises material usage • Provide increased lateral stability • Webs protrude for ease of splicing • Remnant from R2 used as flange
- 31. Whangarei Dry Mill – Box Beam Design Critical Design Actions – R3 Load Case M* kNm N*c kN N*t kN V* kN 1.35G -259.0 34.9 46.7 0.9G+Wu 541.0 -114.0 100.0 1.2G+Wu -589.0 103.0 122.0 Note: Flybraces at purlins both sides of C4 Design Action Lay mm Lax mm Bending (+ve) 1600 Bending (-ve) 7020 Compression 1600 24750
- 32. Whangarei Dry Mill - Splice Design Critical Design Action Effect – 1.2G+1.5Q (over 200 m2 area) M*=150.0 kNm N*c=56.6 kN V*=51.9 kN
- 33. Whangarei Dry Mill – Practical consideration Use full width of billet: • Remnant from 1050x105 solid rafter used as flanges in box beams • Remnant from 1050x42 2 x- band webs used as side wall girts
- 34. Design and detailing – general tips Some important considerations in design/detailing: • For webs and slender sections use x-banded LVL • Use billet multiples and standard sections where applicable • Always include fastener spacing and length • Detail components to be fixed during fabrication • Seal/paint all primary/main frame members to limit moisture uptake • Any lamination of components should include a glue ‘sealant’ to prevent moisture ingress • Spray paint nail patterns on members in the factory • Pre-drill holes where applicable
- 35. Design and detailing – general tips Some important considerations in design/detailing: • Any factory fitted gusset connections to be glue nailed • If using bay lifts, consider stresses applied during construction at joints • Always include bracketry under supply of fabrication contract • Detail brackets to allow for timber tolerances • Use proprietary brackets where applicable • Always add moisture barriers to column/mullion base connections • Box sections can limit the surfaces available to the effects of fire • Use an experienced fabricator
- 37. Merritt Building
- 38. Merritt Building
- 39. Blockhouse Bay Indoor Tennis Centre
- 43. hySPAN portal frame in QLD, Australia
- 44. McCormick Centre for the Environment – Renmark, SA Doweled moment joints with steel fin plates
- 45. 32 m clear span Composting facility, 10 m bays
- 46. Mt Eden Normal School – TCC Floors
- 47. Mt Eden Normal School – TCC Floors
- 48. Thank you Contact: CHH Woodproducts enquiriesaus@chhwoodproducts.com.au Web: www.chhwoodproducts.com.au www.chhsoftware.com Phone: 1800 808 131