Farr Yacht Design gets help from analysis software to meet the rigors of racing on the Disney-backed Pirates of the Caribbean racing yacht...
Farr Yacht Design (FYD) uses NEi Nastran to enhance its structural analysis and simulation for its line of yachts. FYD is a leader in the design and engineering of high performance racing yachts for major events including the America’s Cup and the Volvo Ocean Race, as well as custom and production yachts for builders around the globe.
“Structural analysis is an increasingly important component of successful racing yacht design,” comments Dave Fornaro, FYD design engineer. “We have been utilizing FEA for several years to validate and improve our designs and desired to enhance our suite of analysis tools with more advanced capabilities in several areas including laminated composites, non-linear surface contact with friction, and bolted joints with pre-load. After an exhaustive review, NEi Nastran stood out as the best choice based on its advanced capabilities, cost effectiveness, and quality technical support.”
FYD’s first application of Nastran is for its next generation of designs for the Volvo Ocean Race, a grueling round-the-world race sailed in fully crewed, 70-foot carbon fiber yachts capable of speeds in excess of 40 knots. “These designs are forging new frontiers in ocean racing,” adds Dave Fornaro. “They operate in harsh and brutal conditions and require a rigorous level of structural design and analysis to ensure peak performance and safety.”
Two Phases of Analysis
A typical analysis for a racing yacht is split into two phases: global and detailed. In the global analysis phase, FYD models the entire hull, deck, and internal structure as laminated composite shell elements. A typical model will contain approximately 125,000 elements. The composite materials are orthotropic in nature -- that is, they have different mechanical properties in different directions. This adds an extra layer of complexity as compared to isotropic materials such as metals.
According to Dave, “NEi Nastran has excellent capabilities for modeling laminated composite materials. We use spreadsheets to calculate the properties for individual plies and laminates (collections of plies) based on classical laminate theory. We have developed an automated method for transferring this data from the spreadsheets directly into NEi Nastran...” to read the rest of the story, click here.
