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ING Renault F1 Team engineers are under intense pressure to meet challenging deadlines each racing season when developing complex composite racing cars. The team must completely re-design, manufacture, analyze and test its cars in only sixteen weeks or risk stringent penalties from the Fédération Internationale de l'Automobile (FIA), or worse, the loss of an entire racing season. As a result, the team is constantly striving to reduce cycle times and eliminate errors to achieve a competitive edge.
(Published on November-December 2008 – JEC Magazine #45)
IAN GODDARD, SENIOR CAE ENGINEER, ING RENAULT F1 TEAM
Most early design work on many Formula One cars is based on analysis data compiled from aerodynamic wind tunnel testing, computational fluid dynamics (CFD) simulations and finite element analysis (FEA)/load testing. As a result of these tests and in an effort to create parts that are durable, crash-protective and meet all specifications, analysts have begun to create design data with FEA software by defining composite part thicknesses, boundaries, ply orientations and sequences. But to begin the detailed design process, all this critical engineering data must be transferred to the detailed design team as efficiently as possible so the plies can be recreated in computer-aided design (CAD) software based on the work that has already been accomplished.
It is no small task to efficiently transfer laminate configuration data from FEA analysis tools to detailed composite design and CAD software. Prior to finding a successful, fullyautomated approach, the ING Renault F1 Team used both a manual approach and a semi-automated approach with little success.
Challenges in analysis data transfer
The manual data transfer approach used printed views of each ply from PATRAN analysis software for manual interpretation and freehand modelling in the CAD system. This proved to be a difficult process that took up to two weeks to accomplish and an additional two weeks to “tidy up” the CAD geometry to get it in a usable form. This method forced designers to actually reconstruct ply lay-up data in the 3D CAD environment, thereby consuming valuable development time and only enabling an approximate re-creation of the FEA intended ply boundaries.
In an attempt to improve the manual approach, the team graduated to a semi-automated method that exported analysis lay-up files to a native CAD file. The result was a series of points and rough, jagged boundaries in the CAD software, which again required significant clean-up.
In addition, the resulting single “whole chassis” data file was not usable in the detailed design phase, which requires individual part data files in CAD. A data translator was required to manually break up the whole file, discretionally removing redundant plies to leave just the correct subpart laminate, a highly error-prone and time-consuming task. When tested on the roll hoop, a whopping 20% of the plies were incorrectly specified. Even worse, part weight was often inconsistent because of the errors, which affected the performance of the test cars. Design engineers were never certain if they created plies that truly reflected what the stress team needed to accomplish with each part. It was also unclear whether the final parts would perform consistently from car to car since the process was not truly automated.
The design team needed a simpler, more accurate starting point for detailed design, but none of their existing tools could effectively produce this data efficiently and accurately.
FiberSIM® creates seamless link between analysis and detailed design
Based on its success in working with Vistagy’s FiberSIM® composite engineering software on the previous four generations of its racing cars, the ING Renault F1 Team turned to Vistagy to resolve their data transfer problems when designing the 2008 car. The team’s goal was to seamlessly transfer chassis analysis data directly to the CAD model using FiberSIM. This would provide a very significant head start on the detailed design process and potentially save several days of development time.
Engineers at Vistagy looked at the problem in detail and ultimately created a software utility that enabled the team to automatically transfer the data directly from the analysis software into FiberSIM, which is directly integrated into the CAD system. Using FiberSIM, the engineers were able to automatically consume the analysis data without having to engage in a manual translation process. They found it easier and quicker to programmatically calculate ply boundaries and orientations than starting from scratch. The team simply utilized the boundaries that were directly imported and quickly created the designs.
As a result of the utility, the team – already working under very tight design release timeframes – accomplished two weeks of data transfer and design in two hours. Large, single lay-up files were divided into component laminates and imported into FiberSIM in seconds. The rapid translation times allowed engineers to transfer complete, stand-alone models, saving 97% of the time required for the previous manual approach.
High-quality data was another benefit of using FiberSIM. Because the models were based on actual analysis data, the final geometry was more accurate. In fact, the first time the team ran the software, they achieved a 100% ply success rate, meaning every ply imported into FiberSIM was perfect. The highly-skilled engineers did not have to spend days hand-picking curves and chaining them together. The boundaries could be automatically imported, reducing the overall development time for creating the ply models and sequences by 60%.
The design data was based on the actual mesh edge, so the boundaries were exactly as the analyst envisioned them. FiberSIM captured the data as an original source for the geometry, and helped the engineers associate all annotations and notes directly with the plies in the models. But even more importantly, engineers determined they could engage in another whole week of analysis testing cycles to further reduce chassis weight and increase strength and durability because the transfer process was so fast. The team could build in extra cycles on the front end of the process and still achieve all the required delivery deadlines. This provided critical performance enhancements that improved the competitive edge of the car.
Beating the competition starts in the factory
Most Formula One teams start their fast-paced design process in analysis because analysts have significant experience in predicting loads and designing parts that improve racing performance. But until now, teams did not have a consistent way of translating and transferring data between their state-of-the-art software tools. By using FiberSIM software throughout the conceptual and detailed design phases, as well as to support its entire composites development and manufacturing processes, the ING Renault F1 Team is able to do just that, which makes the design team very competitive indeed. The team is constantly striving to advance every traditional process and method to improve the performance of its racing cars and gain fractions of seconds on the racing circuit. In the high stakes world of Formula One racing, that’s what it takes to win championships.