Team 7: Vincent Borsello, Michael Brill, Daniel Gempesaw, Travis Mease Sponsor: Revenge Advanced Composites Advisor: Dr. James Glancey

Revenge Advanced Composites Composites in marine applications Industry-leading technology Currently designing a new composite boat

Advantages of Composites Design a new composite shock mitigating marine seat and its manufacturing process Problems with current seats: Weight (metals), size Tradeoff: shock mitigating seats vs. payload Advantages of Composites Lightweight Strength only where needed Carbon fabric is approximately five times less dense than steel.

Seat Attachment Mechanism Damping Mechanism Frame Shockwave Insert picture of benchmark seats. Go over all common components. Shockwave Seat (144 lbs) Ullman Atlantic Seat (100 lbs)

Focus: Minimize the weight of the Support Structure while maintaining strength Several parts were pre-selected by our sponsor, Revenge Advanced Composites Semi-active shock absorber The seat will be configured to match our design Boat navigation Controls will be integrated into the prototype Insert solidworks assembly and show the components that we are designing (structure) not seat and shock. Stress these things; Notes: -Seat is an illustrative CAD model….not the actual design (Our sponser will be addressing this problem)

Dynamic Load Damping Capabilities Product Life: 1400 working hours 50% Weight Reduction Relative to Shockwave Seat (144 lbs) Dynamic Load Damping Capabilities 20 G’s Vertical, 4 G’s Fore/Aft, 4 G’s Lateral Product Life: 1400 working hours ~150 instances of worst case vertical load Reduced Footprint/Size Less than 28 x 40 in^2 Manufacturing Best Practices for Pre-impregnated fibers (Prepreg) Later slide with a table comparing what our goals were and then where we ended up… show factors of safety we designed for 20 G’s vertical it can really handle 21.

Arm Base Clevis Pivot Point C-channel Direct load path Minimal footprint Clevis Integrate shock into design Pivot Point Bushing, Rod, Plates 3 1 4 2

Material Considerations Dimensions & geometry Force analysis of structure Material Considerations Strength and Stiffness Curing/Outlife Characteristics Weathering/Corrosion Analyze all modes of failure (6) Manufacturing Issues Mold Designs Ply Patterns Vertical ≈ 20 G’s Fore/Aft ≈ 4 G’s Lateral ≈ 4 G’s Integrate concept design, Modes of failure: Tear-out(material going through walls), Compression, Bending, Deflection, Shear, Pull out (bolts)

8 Shape/Geometry of Structure Applied Loads Varying Thickness Capability Bolt Layout Bolt Sizes Washer Dimensions Bearing Size Pivot Point Mechanism Arm to Seat Attachment Structure to Boat Attachment Load Paths Composite Ply Layout Hole Distance From Edges Clevis Attachment Rider Comfort Material Selection Core Dimensions Adhesive Selection Support Plate Dimensions Seat Dimensions Hole Sizes Composite Manufacturability -Determing each bullet always required several forms of failure analysis -Many of these variables can be broken down into more detailed stuff 8

Derive resultant forces in the entire system Pivot point, shock mechanism, in arm & base Side FBD of Mechanism for illustration purposes

Next step: consider critical areas Knowing the forces in system, use stress and deflection analysis to derive thickness Next step: consider critical areas Approximate arm & base as simple C-channels to calculate moments of inertia

Failure modes for bolts: Tension Pull-out Inter-laminar shear Compression Thickness=t d1 Shear Area d2 Top-down view of base flange Depiction of Tear-out failure

Pivot pin was found to fail due in tear-out Low inter-laminar shear strength of composites Solution: Bond on a metal doubler plate R_bearing X_a Y_a R_rod Cantilever Arm The plot on the left depicts the load carrying capabilities with a doubler plate, analyzing the failure of the adhesive.

Attachment of shock to arm & base Designed to specifications of Active-Shock ActiveShock is specified by RAC Side view of Clevis Plate Top-down view of Clevis Plate

De-molding Bridging Vacuum Molding Draft Angle – 2 degrees Minimum Radius of Curvature – 1 inch Vacuum Molding Extending Mold Surfaces for Vacuum Bagging Insert picture of cad model and then lead up to actual picture, picture of bridging.

1 2 Pre Mold Phase: Cutting of carbon fiber into specific pieces so that they can be laid up “perfectly” into the part…make a joke here about our cutting skills (1,2). Travis measuring and cutting the foam core…state the importance of the core…talk about how we will see it laid up in the part later on. (3) Steve…our hero advisor…thank him for never having faith in us…unloading the mold…talk about how the mold was outsourced b/c of lead times…wouldn’t have been possible to build it ourselves…what its made out of. (4) 3 4

5 7 6 The Mold right in the box! (5) Vince and Mike applying tape around the edges of the mold…a very important process that allows for the application of a vacuum bag and is crucial for proper sealing…need to debulk. (6) Vince, Mike and Travis applying wax…discuss the importance of application of multiple layers of wax…makes surface so smooth that tape will not stick to it and can be blown off. (7) 6

9 8 After a final layer of coating the first ply of carbon fiber is applied to the mold. The puzzle pieces begin to fall into place. It is important that each piece lies flush with the adjacent. (8) We did a real nice job with the first ply, no bubbles or buildup and aesthetically pleasing. (9) First debulking cycle…talk about the two layers on top of the prepreg…white is so it vacuums uniformly and the layer underneath is to prevent the fabric from sticking to the prepreg. (10) Vacuum complete…its crucial to have enough vacuum bag so that it can compress all the way down into the corners…even vacuum…will apply a debulking cycle after 3-4 layers of ply, important for the material to collapse onto itself. (11) 10 11

12 14 Closer look at the vacuum bag and the hose for removing air…sealing around this region is crucial for proper debulking. (12) Application of the core applied after a few plys have been placed down. (13) Cutting special adhesive layer designed for ply-core interfaces. (14) Debulking is a compacting process where you apply a load from a vacuum is applied and relaxed to get the fibers as compacted as possible. 13

16 15 After the mold is cured under vacuum overnight we have the challenge of removing the part from the mold. (15, 16) The part finally removed. (17) 17

19 Layup Mold Part 18 20

22 21 23 25 24 26

Item Weight (lbs) Base 7.69 Arm 3.86 Seat 12.6 Shock 15 Tooling 9.1 Total 48.2 Picture of prototype with wiegtht table of each indiv component

All Target Values have been validated except for Fatigue Life. Metrics Target Values Actual Values Percent Reduction Weight 50 % of 144 lbs 48 lbs 67% G-Loads N/A Vertical 20 G’s 22 G’s Fore Aft 4 G’s 6 G’s Lateral Product Life 1400 hours Unknown - Footprint <28 x 40 (1120 in2) 22 x 24 (528 in2) 53% All Target Values have been validated except for Fatigue Life. Prototype Mold and Parts Cost: $20,000 Describe why fatigue life wasn’t met…future project to validate…tested over x hours

Target the lowest factor of safety Different seat Fatigue Tests Different Materials Carbon Fiber Titanium Bolt on Boat Testing Target the lowest factor of safety Different seat Finish coating/ aesthetics Fatigue tests…where we go from here.

Michel Lourdemarianadin Hope Deffor Steven Beard Jon Sadowsky RAC Stephen Andersen Jim Glancey Michel Lourdemarianadin Hope Deffor Steven Beard Jon Sadowsky RAC Special Warfare Group 7 Insert special warfare pictures,