8. Framing, Stiffeners and Foundations

8. Framing, Stiffeners and Foundations

Marine Composites Framing, S+ffener and Founda+on Design Marine Composites Webb Ins1tute Senior Elec1ve Spring, 2013 Framing, S1ffener and Founda1on Design Eric Greene, Naval Architect EGAssoc@aol.com 410.263.1348 410.703.3025 (cell) hNp://ericgreeneassociates.com/webbins+tute.html Webb Ins+tute Senior Elec+ve – Spring 2013 page 0 High-­‐Efficiency Recrea1onal Power Boat Marine Composites Framing, S+ffener and Founda+on Design Structure Showing Framing with Carbon Skins over PVC Core Water-­‐Jet Cut and Folded SeNees Presented by Eric Jolley, Bieker Boats, SeaNle, 2008, WA, USA at the First Chesapeake Power Boat Symposium, Annapolis, MD, USA Webb Ins+tute Senior Elec+ve – Spring 2013 page 1 Bulkhead Installa1on Marine Composites Framing, S+ffener and Founda+on Design This carbon fiber/Nomex bulkhead has the aNachment flange molded with the bulkhead and bonded to the hull with a flexible epoxy adhesive Bulkheads installed in epoxy composite 54' sloop from Alden Yachts of Portsmouth, RI Webb Ins+tute Senior Elec+ve – Spring 2013 page 2 Bonded Pultruded Structural Members Marine Composites Framing, S+ffener and Founda+on Design Atlas Hovercrae of Florida planned to build commercial hovercraes in the US using bonded pultruded structural profiles to develop the large, flat surfaces. Webb Ins+tute Senior Elec+ve – Spring 2013 page 3 Frigate to Yacht Conversion Marine Composites Framing, S+ffener and Founda+on Design Pultruded s1ffeners used by Compmillennia, LLC, Washington, NC Webb Ins+tute Senior Elec+ve – Spring 2013 page 4 Bulkhead Detail with PuOy Fillets Marine Composites Framing, S+ffener and Founda+on Design Illustra+ons courtesy of ATC Chemical Corpora+on (now Gurit). Drawing is for guidance only – actual laminates should be engineered to specific requirements in accordance with classifica+on society rules. Webb Ins+tute Senior Elec+ve – Spring 2013 page 5 Bulkhead AOachment Stresses Marine Composites Framing, S+ffener and Founda+on Design Loading Transferred From Deck Compartment Flooding Loads Peel
Stress
Stress
Concentrations
Shear Stresses
Hydrostatic,
Slamming and
Blocking Loads
Webb Ins+tute Senior Elec+ve – Spring 2013 page 6 Preform Bulkheads PRISMA preformed stringers are shown here during construc1on of a 42-­‐S CigareOe hull Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design Stock preform bulkhead page 7 Honeycomb-­‐Cored Carbon Fiber Bulkheads Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design page 8 Bulkhead Installa1on Bulkheads installed in epoxy composite 54' sloop from Alden Yachts Marine Composites Framing, S+ffener and Founda+on Design Cockpit support bulkheads on lightweight racing sailboat www.boatdesign.net Webb Ins+tute Senior Elec+ve – Spring 2013 page 9 DDG 1000 Deckhouse Secondary Bonding Marine Composites Framing, S+ffener and Founda+on Design Complex 2D Joint (below) and 3D Joint (right) The DDG 1000 composite deckhouse contains over 8,500 linear feet of 2D composite joints and 460 3D joints Webb Ins+tute Senior Elec+ve – Spring 2013 page 10 Frame and Longitudinal Intersec1ons Marine Composites Framing, S+ffener and Founda+on Design l
Webb Ins+tute Senior Elec+ve – Spring 2013 page 11 Hat S1ffeners Marine Composites Framing, S+ffener and Founda+on Design Example of a single skin FRP s+ffener to illustrate the design process taken from USCG NVIC No. 8-­‐87 Webb Ins+tute Senior Elec+ve – Spring 2013 page 12 S1ffener Construc1on Details Tabbing Detail Marine Composites Framing, S+ffener and Founda+on Design S1ffener to Bulkhead Connec1on Illustra+on courtesy of ATC Chemical Corpora+on (now Gurit). Drawing is for guidance only – actual laminates should be engineered to specific requirements in accordance with classifica+on society rules. Webb Ins+tute Senior Elec+ve – Spring 2013 page 13 Examples of S1ffener Systems Marine Composites Framing, S+ffener and Founda+on Design Whatever type of stringer system is used, installa+on alignment is cri+cal as this impacts the installa+on of interior subassemblies. Some types of systems used include: •  Custom, built-­‐up systems glassed in place with secondary bonds •  Grid systems built on a separate mold bonded to the hull with either bedding compound or adhesive •  Preform stringer systems installed using either primary or secondary bonds Sailboat Grid Stringer System (Benateau USA) Preform Stringer Installa+on Failed Grid Stringer Installa+on Webb Ins+tute Senior Elec+ve – Spring 2013 page 14 Preform S1ffeners Marine Composites Framing, S+ffener and Founda+on Design A preform is an assembly of dry reinforcement held together some way in a form that closely resembles the final geometry. In this case of preforms used for boat s+ffeners, the fiber is held in place by an expanded foam core. Webb Ins+tute Senior Elec+ve – Spring 2013 page 15 S1ffener Stresses Marine Composites Framing, S+ffener and Founda+on Design Hull Bending Moment Stress
Concentrations
Webb Ins+tute Senior Elec+ve – Spring 2013 page 16 Grid Systems Reinforcement is Added to Structural Grid Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design World Cat Power Catamaran Structural Grid System page 17 Marine Composites Framing, S+ffener and Founda+on Design Bonded Structural Grids Solid fiberglass grid system is bonded to the hull with methacrylate adhesive Mari+me Marine, LLC, Augusta, Maine ITW Plexus ACRALOCK by Engineered Bonding Solu+ons, LLC Southport Boats Augusta, ME Webb Ins+tute Senior Elec+ve – Spring 2013 page 18 Deep Stringers Marine Composites Framing, S+ffener and Founda+on Design These solid foam stringers are fully encapsulated with fiberglass laminates and reinforced with a carbon composite layer. [R&R Boatworks, Stuart, FL] This stringer system is aNached to the hull with methacrylate adhesive [Southport Boats, Augusta, ME] Webb Ins+tute Senior Elec+ve – Spring 2013 page 19 Typical Engine Girder Arrangements Girder Built from Solid Laminate Marine Composites Framing, S+ffener and Founda+on Design Cored Engine Girder ABS GUIDE for High Speed Naval Crae, 2007 Part 3 , Chp 2, Sect 6, Structural Details Webb Ins+tute Senior Elec+ve – Spring 2013 page 20 Examples of Engine Girders Marine Composites Framing, S+ffener and Founda+on Design Engine Girders Tie in to Transom Failed Engine Girder Engine girder cracking apparently from improper hauling sling arrangement Ae end of engine girders of Sabre 38 Express Webb Ins+tute Senior Elec+ve – Spring 2013 page 21 Aluminum Saddle over Engine Girder Marine Composites Framing, S+ffener and Founda+on Design Aluminum saddle is fiNed to composite girder Webb Ins+tute Senior Elec+ve – Spring 2013 page 22 Examples of Transom Structures Marine Composites Framing, S+ffener and Founda+on Design A water-­‐
saturated transom undergoing repair at Penguin Composites in Australia Most Dive Boats Have Large Transom Openings A repaired stress crack as shown in inset photo Hinged Transom featured on 10 m Yacht from C.H. Marine Yachts, Shelter Island, NY Webb Ins+tute Senior Elec+ve – Spring 2013 page 23 Transom Engine Mounts Typical through-­‐bolt detail Marine Composites Framing, S+ffener and Founda+on Design Contemporary outboard bracket with internal bracket support Webb Ins+tute Senior Elec+ve – Spring 2013 www.BoatDesign.net page 24 Framed Single Skin Transoms Marine Composites Framing, S+ffener and Founda+on Design Boundary Condi1ons and Applied Forces for Single Engine Plywood Transom Deflec1on of GRP Plywood Transom with Twin Engine Loading Boundary Condi1ons and Applied Forces for Single Engine Framed Transom Deflec1on of GRP Framed Transom with Twin Engine Loading The framed single skin transom is s+ffer and stronger than the GRP plywood transom. Ronnal P. Reichard, “Framed Single Skin Laminate Transoms,” COMPOSITES 2006, St. Louis, MO Webb Ins+tute Senior Elec+ve – Spring 2013 page 25 Transom Failures Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design page 26 S1ffener & Detail Design Flow Charts Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design page 27 Machinery Founda1ons Typical Founda1on Systems Marine Composites Framing, S+ffener and Founda+on Design Filament Wound Machinery
Foundation by Brunswick Defense
Webb Ins+tute Senior Elec+ve – Spring 2013 page 28 Founda1on Design Parameters Webb Ins+tute Senior Elec+ve – Spring 2013 Marine Composites Framing, S+ffener and Founda+on Design page 29 Framing Systems Summary Marine Composites Framing, S+ffener and Founda+on Design •  Longitudinal and transverse framing systems reduce the span of panel sizes and allow the hull and deck to respond as a global structure •  Frames and stringers can be built outside of the hull and bonded in place or built up directly in the hull •  Unidirec+onal reinforcement is most effec+ve on the top of stringers while ±45° material is most effec+ve for sidewalls and tabbing •  Avoid direct contact of “hard” framing edges and hull •  Careful fit-­‐up and tabbing or bonding of structural grid systems is cri+cal •  Deep engine girders may require bracing for transverse stability •  Equipment founda+ons with can+levered geometries can produce high bending moment stresses in the areas where the founda+on meets the hull Webb Ins+tute Senior Elec+ve – Spring 2013 page 30