CAD/CAE технологии помогают одержать победу в велогонке Tour de France
Karen Auguston Field -- Design News, November 7, 2005
Seven-time-winner Lance Armstrong's Discovery Channel team won the first team time trial early in the race. Armstrong placed second in the first-day individual competition against the clock. And he cruised over the finish line in the number one spot in the final, 55-km individual time trial in Stage 20 near the end of the tour and on, of course, to overall victory.
This year's Tour de France, however, included an unofficial, yet no less critical race against the clock. Only instead of elite cyclists attempting to snag a yellow jersey, it was designers and engineers of Trek's Advanced Concept Group straining to beat the clock in their quest to propel Armstrong to an unprecedented seventh win.
In just 28 brutally short days, the team completely redesigned the TTX time trial frame that Armstrong and his team rode in this year's time trials and in several past Tour de France time trial wins. Like the bike Trek introduced in 2000, the frame is made of carbon fiber cloth with an areal density of 110 gsm, molded using a patented process known as Optimum Compaction Low Void (OCLV) for low weight, high stiffness.
But little else remains the same. Among the major design changes on the TTX bike:
- Head tube: Deeper cross section to help create lift in cross winds, yet be more aerodynamic in head winds; a narrower cross section to decrease frontal area for better aerodynamics; and a shaped design that creates stiffness in the front end of the bike
- Seat tube: Added cut-out to facilitate air transition from the frame tubes to the rear wheel; deeper cross section to help with lift in cross winds
- Aero bar: All new, one-piece design eliminates drag; OCLV carbon construction re-duces weight and increases stiffness
- Overall lengthening of the wheelbase for better ride characteristics
- Complete redesign of the cable routing
Design improvements in Lance Armstrong’s TTX time trial bike helped power him to a first place finish at this year’s Tour de France (the triathalon version is shown here).
"We were first approached about the possibility of doing this redesign the third week of April, which meant we had to have a bicycle delivered to Lance in under 30 days in order for him to test it out before the Tour de France," says Trek Senior Designer Michael Sagan.
Sagan is the technology principal responsible for industrial design and for acquiring and integrating all hardware and software tools. "Thanks to advancements in software tools, the cycle time to complete a bicycle design has been getting faster and faster" he says. "But up until now the quickest we had ever done an extensive redesign like this had been four months—now we had just four weeks to do it."
Sagan figured that Trek's Advanced Concept Group would be able to pull it off, but only if they leveraged every trick in their software toolkit. It's comprehensive to say the least—starting with Alias Studio Tools for creating concept sketches and final surfaces to Solidworks 3D CAD for mechanical design and analysis tools like CFdesign for virtual wind tunnel studies and COSMOS for simulation modeling. (See the complete toolkit on following page.)
While these software tools are integral to the design effort, Sagan says that in the past it was sometimes difficult to manage even small design changes without impacting the integrity of the design. "Bike design is a magic combination of both intuition and analysis—it's a very iterative process, which can be challenging when you have lots of hands touching the model, and that model is constantly changing."
This year Trek added thinkid from think3 to its toolkit. The industrial design tool features a capability called Global Shape Modeling that works like this: When a user deforms a solid shape or surface, the software automatically makes the necessary geometry calculations to accommodate the shape change and maintain design integrity. Sagan says that this capability allowed the team to make time-critical geometry changes without impacting design intent or production capability—two issues they struggled with in the past. They also slashed time from the process. For example, geometry changes to the frame that once took hours took only minutes.
Sagan also credits the use of AMD Dual Opteron Architecture running on HP 9300 workstations for the quick turn around time. "We saw over 50 percent speed improvement in running our FEA analyses," he says.
Not only did Trek beat the clock, but Sagan says the new bike is 10 percent faster than last year's production bike, 2 percent lighter, and 15 percent stiffer—characteristics that add up to better ride performance and quality.
No kidding. Those improvements powered Armstrong to a second place finish in the first individual time trial of the race, a win in the team time trials that first earned him the yellow jersey, and the individual time trial win that secured him an unprecedented seventh Tour de France win.
Not to be overlooked is the fact that an aerodynamically superior bike allows the rider to expend less energy. That turned out to be critical for Armstrong in the individual time trial in Stage 20 near the end of the Tour de France, which he won after logging some 3,200 kilometers in the race.
"Anytime we shave weight or add an aerodynamic advantage, it's like banking watts. The rider is not expending energy needlessly," says Sagan. "And that's a great thing."
Wes Wilcox | Director |
Michael Sagan | Senior Designer/Technology Principal |
Hans Eckholm | Industrial Designer |
Chad Bailey | Senior Graphic Designer |
Scott Nielson | OCLV Engineering |
Doug Cusack | Lead Frame Engineer |
Paul Andrews | Fabrication Engineer |
Damon Rinard | CFD Design and Analysis |
Mike Zeigle | Prototype Shop Supervisor |
Dan Trapp | Prototype Staff |
Paul Towne | Prototype Staff |
Jarod Brown | Prototype Staff |
Hans Eckholm | Designer of the TTX Triathlon Bike |
David Bloom | Designer of the TTX Triathlon Bike |
HARDWARE TOOL | VENDOR | DESIGN ACTIVITY | WEBSITE |
HP 9300 workstations (with AMD Dual Opteron Architecture) | Hewlett Packard | Analysis and design | http://rbi.ims.ca/4400-556 |
Wacom | Cintiq Drawing Tablet | Conceptual design | http://rbi.ims.ca/4400-557 |
SOFTWARE TOOL | VENDOR | DESIGN ACTIVITY | WEBSITE |
Adobe Illustrator | Adobe | Decals and color design | http://rbi.ims.ca/4400-558 |
Alias Studio Tools | Alias | Conceptual design | http://rbi.ims.ca/4400-559 |
CFDesign | Blue Ridge Numerics | CFD design virtual tunnel analysis | http://rbi.ims.ca/4400-560 |
COSMOSworks | SolidWorks | FEA analysis | http://rbi.ims.ca/4400-561 |
PowerMILL | Delcam | CAM system for producing CNC paths | http://rbi.ims.ca/4400-562 |
SolidWorks | SolidWorks | 3D mechanical design | http://rbi.ims.ca/4400-563 |
SurfCAM | Surfware | Parts fabrication and assembly | http://rbi.ims.ca/4400-564 |
thinkid | think3 | Time critical design changes | http://rbi.ims.ca/4400-565 |