Modine Manufacturing needed to quickly

implement a finite element analysis (FEA)

system to improve their inefficiencies and

decrease their design costs.

IntroductionEven if you are not really a “gear-head,” you probably

know that the engine under your car’s hood utilizes a

balanced air/fuel mixture to generate power. What youmight not be aware of is that when you turn the key,only 25% of the energy created by your engine is actu-ally transferred to the vehicle’s operation. The remain-ing 75% must be evenly distributed from the engine tothe environment inside and outside the vehicle. Thisprocess is known as “heat transfer” and it is importantfor maintaining a vehicle’s performance, as well asminimizing the amount of harmful emissions pro-duced by the vehicle.

Modine Manufacturing Company of Racine, Wis.(U.S.A.) specializes in the development of small tomid-sized systems designed to transfer this consider-able amount of energy away from the engine to otherareas of the vehicle. Since its inception in 1916,Modine Manufacturing has emerged as one of the pre-mier makers of heat exchangers and climate controlsystems–particularly in the automotive and off-roadindustries–holding hundreds of heat-transfer systempatents.

ChallengeIn 1999, the New Product Development group at

Modine Manufacturing launched an in-depth investiga-

tion into the company’s product development process

in an effort to increase the rate of successful testing. Atthe same time, the group hoped to reduce the lifetimecost of these diverse and intricate systems, thusimproving overall customer satisfaction.

For many years, Modine Manufacturing utilized com-mercial Computational Fluid Dynamics (CFD) soft-ware–in conjunction with its own, internally devel-oped heat transfer/heat exchanger design programs–to determine its products’ optimum performance.Meanwhile, structural integrity issues were typicallyaddressed in multiple physical prototyping and testingcycles.

To be more specific, the structural integrity of consecutive design variations was often addressed insuccessive iterations of building and testing partial orcomplete physical prototypes. In many cases, withoutthe benefit of a fully trained structural engineer onhand. The investigation revealed that these physicalperformance tests needlessly expended an exorbitantamount of money.

While it’s fair to say that performance sells heatexchange products, adequate structural integrity isultimately what keeps them on the market. The groupconcluded that Modine needed to quickly implementa finite element analysis (FEA) system to improvetheir inefficiencies and decrease their design costs.

SolutionConsidering the characteristics of the company’s

expansive product line—combined with the limited

availability of a trained structural FEA engineer—the

New Product Development group chose to implement

a structural FEA pilot program within the company’s

Truck Division.

After much deliberation, the group determined thatANSYS Inc. offered Modine its most compatiblestructural simulation system.

EXECUTIVE SUMMARY

Challenge:Eliminate needless expenditures on

physical testing of automotive heat

transfer systems

Solution:Implement an ANSYS/Professional-

ANSYS/Mechanical based pilot pro-

gram to improve design efficiency

and reduce costs

Benefits:Development time of an inlet air

cooler tank reduced by 12 weeks

Development cost of inlet air

cooler tank reduced by $18,000

Design optimized in only two

iterations

Grand total of $750,000 avoided

on 12 projects conducted in an

18-month pilot period

Pilot Structural FEA Program Unveils Substantial SavingsM O D I N E M A N U F A C T U R I N G C O M P A N Y

CASE STUDY

www.ansys.com

Figure 1—ANSYS stress simulation oforiginal inlet air cooler tank designIm

ages

cou

rtesy

Jos

eph

Fiet

kiew

icz,

Mod

ine

Man

ufac

turin

g

“ANSYS was chosen for its versatility and robust-ness, particularly in screening multiple design vari-ations of small and mid-size models,” said JosephFietkiewicz, Modine’s principal FEA engineer. “Itoffers a powerful yet easy-to-understand internalmacro-language (APDL), as well as adequate translators for Pro/ENGINEER and Unigraphics.”

According to Fietkiewicz, the ANSYS suite provedto have a particularly effective tool set for dealingwith the industry specific heat exchanger/pressurevessel problems presented by Modine’s applica-tions. Moreover, ANSYS’ ability to classify stressesalong an arbitrary section path makes it compatiblewith the ASME B&PV Code, BS7608 andEurocode 3–both of which use the concept of nom-inal stress as a basis for fatigue evaluations.

Specifically, ANSYS/Professional demonstratedexcellent performance on all practical mechanicaland thermal problems–both steady state and transient–at an extremely attractive price.Moreover, the ANSYS/Mechanical package offeredintegration with LS-DYNA and FLOTRAN as wellas excellent non-linear analysis features.

“This was an important consideration for Modine,”notes Bob DeGroot, the Modine Truck Divisionstructural FEA engineer, “because although inter-pretative linear analysis is the essence of FEA in acommercial environment, in certain cases non-lin-ear analysis must also be prescribed.”

This combination of ANSYS/Mechanical andANSYS/Professional created a powerful platformfor Modine, enabling adequate scalability and uni-formity within the confines of the company’s prod-uct development system.

Among the 12 projects the pilot team addressedover an 18-month period was an inlet air cooler tankillustrated in Figures 1 & 2. The tank is “construct-

and storage of Modine’s structural integrity expertise.”

After a single re-tooling iteration, the tank was cer-tified in a single iteration of pressure cycle testing.The overall development time of this particularproject was reduced by 12 weeks and the estimated$18,000 development price tag was avoided.

BenefitsThe Modine Manufacturing structural FEA pilot

project proved an unmitigated success as more than

$750,000 in development costs, conservatively, was

identified during the 18-month control period. Thisfigure does not take even further stages of the prod-uct life cycle–or intangibles such as improvedproduct quality, higher customer satisfaction, andan increased internal confidence level resulting in ahigher successful bid ratio–into consideration.

Consequently, substantial financial reserves havebeen revealed to exist within the organization.Additionally, the necessary organizational frame-work–with the appropriate structural FEA expert-ise–was created along the way.

As a result of their efforts, the 18 teams participating in the project received company-widerecognition, winning the first Modine President’sAward for savings and waste avoidance.

While the pilot project mainly concerned the inte-gration of structural FEA into the testing activities,similar opportunities exist for expanding simulationinto certain manufacturing processes with subse-quent spring-back–such as stamping and drawing.The development of the distributed structural FEAsystem at Modine will remain an ongoing process.Its ultimate goal is not necessarily to destroy andreplace the old process, but rather to evolve it intoa more-controlled method using the best availabletools.

ed” of cast aluminum and its complex geometry isnot easily addressed by standard analytical meth-ods. Traditionally, to certify this structure at therequired operational pressure, a hardware prototypewould have been built and tested.

Simplified modifications of the structure were firstperformed in ANSYS using the beam element postsand shell element baffle. As seen in Figure 1, the ini-tial half-geometry tank has four posts of interest,connecting the opposite sides of the tank, to counteract the pressure inside the tank. The postsection was chosen to withstand membrane stressesas defined by the ASME B&PV Code. In turn, thelocation of the post was determined by minimizingthe linearized bending stress.

Stress concentration factors were analytically eval-uated. Consequently, the designer modified theoriginal CAD model to give it full solid geometry,

including the radii. The resulting CAD model wascleaned in CADfix, then imported into ANSYS andanalyzed. The tank in Figure 2 shows the revisedgeometry with the number of posts reduced to twoand the baffle mounted within the inlet.

“ANSYS may be used in tandem with CADfix toimport data from both CATIA and I-DEAS,”observes DeGroot. “This gives ANSYS a commoncommunications platform, important for the support

Southpointe; 275 Technology DriveCanonsburg, PA 15317; U.S.A.

ansysinfo@ansys.com

ANSYS is registered in the U.S. Patent and Trademark

Office. ©2002 SAS IP, Inc., a wholly owned subsidiary

of ANSYS Inc. All Rights Reserved.

MCS0087-JUL02

www.ansys.com Toll-Free:1.866.ANSYS.AI (1.866.267.9784)

Toll-Free Mexico: 001.866.ANSYS.AI

CASE STUDY“Although interpretative linear analysis is the essence of FEA in a com-

mercial environment, in certain cases non-linear analysis must also be pre-

scribed,” Bob DeGroot, Modine Manufacturing.

Figure 2—ANSYSstress simulation ofrevised inlet air coolertank design