16 December 2008
16 December 2008
High Modulus was commissioned by Isotop (France) to provide an engineering design solution for the carbon rudder quadrant of a 100ft high performance sailing boat, with the key objective of reducing weight.
The final quadrant is debuting at METS in Amsterdam this week.
A standard quadrant design is often a flat cored panel with a base laminate and patching to provide additional strength near the stock. High Modulus engineers reviewed this design and found that 30-50% of the final weight could be due to the core only, which is present to provide in-plane buckling stability and some out-of-plane strength. High Modulus used FEA to investigate whether a quadrant could be designed without the core – therefore have a significant reduction in weight - and still perform well.
High Modulus first ran an FEA solid element topology optimisation, based on the space available, as well as the geometry constraints at the stock and in the rope guide area.
After the initial optimisation, and further discussions with Isotop about the build process, High Modulus developed a surface model. The solution comprised two 'clam-shell’ halves, each to be female moulded and bonded back to back, ensuring the exact laminate and patching arrangement could still be optimised to meet the chosen shape.
The next stage was a shell element topology optimisation, which helped define the patch size and location for each ply and orientation within the lay-up. The results were reviewed and used to create the first draft of construction drawings, before a further FEA iteration was run as a final check, also confirming sufficient buckling stability performance. The construction drawings were issued to Isotop along with the part geometry, which Isotop converted into mould geometry.
The final design solution, which included carbon unidirectional and carbon double bias prepregs, offered a significant 25% weight reduction over a typical quadrant.
Cobra International is celebrating its 40th year and has commissioned a book that will look at 40 key projects and 40 key people that were integral to the company’s growth. ‘Klaus Simmer and The King Cobra: A breakthrough in surfboard design and production technology’ is an extract article from this book and a breakthrough composites product for Cobra, establishing its presence as a manufacturer of high performance windsurf boards and creating global visibility for the Cobra brand.
Technical Fibre Products will showcase its Optiveil nonwovens at China Composites Expo in Shanghai on 5-7 September.