Making the Grade

By Louise Elliott

CAE data management, until very recently more desire than reality, isfinally becoming available. In the September issue, DE looked at twodifferent approaches to achieving it, and for this supplement, spokewith early users of those two systems.
As is often the case, the earliest adopters come from the aerospace andautomotive industries. The Chrysler Group of DaimlerChrysler chose touse MSC.SimManager from MSC.Software. The Mechanical Systems Divisionat NASA’s Jet Propulsion Laboratory decided to standardize on UGStools, including using Teamcenter for CAE data management.Chrysler Group and MSC.SimManager

“Over the last 10 to 15 years, CAE has transitioned from a sometimesoptional service tool to critical path for design decisions made in anenvironment where engineers do 15,000 high-performance computeranalyses per month,” says Larry Achram, director of Virtual Engineeringand Crossfire for the Chrysler Group. “Too often, the engineers storethose analyses wherever is convenient, some are on desktops or otherplaces where they’re hard to find and manage. We were drowning in ourown output—and I don’t think we’re unique in that.”

The 230 people in Achram’s team comprise the CAE team, with theexception of computational fluid dynamics (CFD) and ride and handlinganalyses, for the Chrysler Group. Those simulations include a number ofdisciplines that link together to create noise, vibration, andharshness (NVH), crash, durability, and occupant safety simulations.Although Chrysler standardized all design on a single platform (CATIA)some years ago, Achram says that the company did not want to link allCAE tightly to that platform. “The CAD load in PDM is so big thatadding more to it would be both too much and too difficult to manage.It made more sense for us to be able to track CAE in parallel to PDM.”
Even more important, he believes, is the ability to link different usesof the same design, and make sure all the parameters are linked aswell. “Knowledge-based design automation collects Chrysler’s way ofdesigning systems and subsystems, and find the parameters that can beinterchanged among different products,” Achram says. “For example, ifwe take the basic architecture of a brake rotor that can be used for asmall car, mid-size car, large car, and heavy truck, knowledge-basedtools can size the rotor appropriately, or jump up from four lug boltsto five—so that we don’t have to design each configuration fromscratch.”

Throughout the process, he says, the engineers have options: to analyzewith CAD, before or after final design, and whether or not to keep theanalyses. But because the analyses still have to be tracked andassociated with the right designs, the company studied a number of waysto manage the CAE data and decided on MSC.SimManager, because it “wouldwork with legacy systems and help Chrysler get out of the customsoftware business,” said Achram. “We really want to minimizecustomization, and MSC understood that. We’re in the business ofcreating great cars and trucks. We don’t find it a competitiveadvantage to have a home-grown customized virtual engineeringenvironment.”

Chrysler believes that SimManager will help the company use and re-useCAE data at different lifecycle stages—concept, design execution, andmaintenance, and that in so doing, it can provide an important PLMlink. “At the concept stage, we don’t need to reinvent what we alreadyunderstand. We can leverage the knowledge we have in CAE data,” hesays. “So many trade-offs can be based on 15,000-plus runs that itbecomes distracting. The people who do those runs are driving majordesign trade-offs, and we think that being able to reduce the number ofanalyses that have to be repeated has great productivity benefits.”

He adds that his engineers find that SimManager, even in its very earlydays of implementation, makes their jobs easier. “They’re happy to havepower tools to help. The market is driving shorter lead times, whichputs even more pressure on them.”

In August 2002, the Mechanical Systems Division at the Jet PropulsionLaboratory (JPL), a NASA center managed by the California Institute ofTechnology, decided to use a single source for all the tools it usesfor large-scale projects. The division chose a mix of products fromUGS: Teamcenter for PDM/PLM; NX 3 for CAD; kept I-deas for pre- andpostprocessing of analyses; TMG for thermal modeling; and NX Nastran asthe overriding computing engine.The kind of work done by JPL could not be more different from thatdone  by Chrysler. Rather than create vehicle designs for amassive market, the lab designs specialized spacecraft of enormouscomplexity, and makes them in ones or twos. According to JPL HardwareDevelopment Process Engineer Clark Briggs, “We started out wanting tocreate a collaborative environment so that different people could seedifferent versions or parts of a design without having to launch anyauthoring tools, and now we want to get the analysts connected as well.”

Analysis results go into Teamcenter, and JPL is moving to a process inwhich analysis no longer stands alone. “Design geometry can be obtainedfrom the PDM system, analysis models can be put into it along withresults,” says Briggs. “I’m a believer in trying to improve rapidresponse to and from analysis and tie it to tracking the design. Weneeded to supply versioning and visualization controls, and that’s whywe wanted CAE data integrated into PDM.”
He points out that analysts want to be able to find and reuse priorwork. Although the system does not yet have the ability to hold data onloads and restraints nor search for it, at the moment, Briggs says,that information “goes into Word reports associated with the I-deasmodel in PDM, but we can’t yet search with a ‘load’ criterion.”

Aerospace generates internal loads for projects, he says, for all-usecases. “In the future, the system will see and break them out for alllevels of a design. When that becomes a managed activity, it will makereview and assessment of designs much easier. Everyone will have afully checked system, with cleaner input sets available to them withless effort. Now it’s manual, which takes a lot of time. The completedsystem will provide internal loads for individual design versions anditerations, and we can be sure the loads are correct for a specificiteration. The same will be true for boundary conditions and materialproperties.”

Briggs believes that obtaining workable tools for managing CAE dataposes few technical problems. Rather, gaining acceptance from CAE usersto make their unfinished data viewable to the outside world, andgaining financial support from management will be the next hurdles.Associativity has real benefits but, he says, “it’s an educational sellto get people who don’t use CAE to buy into this, because it’sexpensive.”

Contributing Editor Louise Elliott is a freelance writer based inCalifornia. Offer Louise your feedback on this article through e-mailby clicking here.

Chrysler Group, Inc.
Auburn Hills, MI

Jet Propulsion Laboratory
Pasadena, CA

MSC.Software
Santa Ana, CA

UGS Corp.
Plano, TX