Automotive Development: All Eyes on CAE Weight Management

Keywords: Optimization, Automotive, Lightweight

The automotive development process

is still focused on objectives such as

durability and crash safety, while weight is

often limited to the very end of the design

process. Through the establishment of the

“Optimization Center” (OC) concept, Altair

ProductDesign has developed an innovative

design model combining performance

features with weight reduction goals. This

article describes the OC concept dealing

with everything from the optimization

of single components to an entire

optimization process known as “CAE

Weight Management”.

During the last few years, an increase in

engine efficiency has been achieved across

the automotive sector but these days,

weight reduction is increasingly seen as the

next step to lower the energy consumption

and CO2 emissions of vehicles. Automotive

manufacturers have started to not only look

at the overall fleet emissions of CO2 [1], but

have also begun to realize the advantages

of weight reduction in a vehicle’s overall

lifecycle. To obtain the best possible results,

it is important to give as much priority to

weight goals as to other functional attributes

such as durability or crash safety.

An early combination of weight goals with

these attributes enables a better design of

components and assemblies while lowering

the overall development effort. In Altair

ProductDesign’s OC concept, a consulting

team of highly qualified specialists follow this

strategy and are able to break a negative

weight spiral or even turn it around.

IndustryAutomotive

ChallengeMinimize vehicle weight

Altair SolutionIntegrate optimization methods at the very early stages of the development process through optimization centers

Benefits•Lightweight, high performance design•Manufacturing cost savings

Key Highlights

Authors: Lars Fredriksson, Director Altair ProductDesign Germany & Armin Veitl, Director of Design Altair ProductDesign Europe

Article

The Gateway to Design InnovationThe successful implementation of

Optimization Centers throughout the

aerospace industry has already resulted

in significant weight savings on metallic

and composite components. Pilot projects

in the automotive industry have proved

- with similar significant weight savings -

that Optimization Centers can also bring

advantages to this sector.

Automotive engineers have different

weight reduction methods at hand, from

the development of new designs or use

of new materials to the application of an

alternative manufacturing approach. Several

of these strategies combined in an optimal

manner can reveal opportunities to reduce

unnecessary material. Form, material and

production methods can be tuned to meet

the optimal requirements.

Computer aided engineering (CAE) methods,

such as structural optimization, are being

applied to find and exploit this weight saving

potential. The success of CAE optimization

depends on how and when optimization

methods are applied to the development

process. The question “how” is answered

best by placing it strategically within the

context of project organization and it

should be handled as closely as possible in

collaboration with the design department.

The answer to “when” is simply “the earlier

the better”, with “simulation driven design”

being the term which best summarizes this

approach.

Tailored Optimization CentersThe concept of an Optimization Center

has been developed to simplify the access

to, and to enhance the benefit of, CAE

optimization. Initially introduced to reduce

the mass of individual components by

changing their form, Optimization Centers

have developed into a consulting approach

for functional concepts and material

decisions on an assembly level. The Altair

ProductDesign concept of Optimization

Centers provides close cooperation of

optimization experts (including topology,

topography, form and parameter

optimization), who are made available to

work on-site at the customer site and offer

individual services on an exclusive basis.

Under this approach, the effort of integrating

optimization into the development process

can be kept to a minimum. Every OC is

scalable as it is possible to add additional

resources to every team as needed.

Additionally, Altair ProductDesign

recommends including the customer’s staff

into the project team to foster knowledge

transfer within the group, and questions

such as available design space, possible

manufacturing processes or the relevant

functions can be discussed and answered

quickly, leading to a minimum loss of

communication and a maximum output.

Depending on the requested level and

integration of the Optimization Center, the

experts will work directly and closely with

each department involved.

The first level of an Optimization Center

is the direct cooperation with the person

responsible for components within each

functional group or team. Usually, since

the components' material and production

processes are already pre-defined, the

experts can directly search for unused and

removable material. An overall assessment

of cost effectiveness of components to

control resources by importance is not done

at this level.

The next level of method integration is

based on cooperation with the OEM’s

project managers of the systems or of the

full vehicle. Those engineers have the power

Component Level Optimization Performed on Six Components Screened Down from an Initial Twelve

The Optimization Center assesses decisions and their impact on the development processes

to change functionality within the system

or vehicle, which offers a higher potential

for optimization since it is not necessary

that each component becomes lighter to

reach the system’s optimum. It is possible

that single components

– due to a change of

function – might even

be heavier, but with an

overall optimization of

the system, this can be

more than compensated

for in other areas. At this level of method

integration, it is also possible to do an

overall assessment of cost effectiveness.

Since the entire system is analyzed, the

engineers can apply advanced selection

processes to prioritize certain topics.

CAE Weight ManagementThe direct support of the weight

management department of an OEM is

known as “CAE Weight Management“.

With the implementation of CAE Weight

Management into the weight management

department, the team gains direct access

to all available knowledge of the CAE

studies (concept optimization, feasibility

studies, robustness analysis and stochastic

assessments) and can also request these

types of studies to be made, to gain as much

information on weight and performance

as possible. In this way, the weight

management department

can draw better and

more reliable conclusions

regarding the development,

and can be more precise

on the input requirements

needed to reach the weight

goals. Information that an OC can deliver to the weight management department includes:

• an early understanding of the optimized basic structure and the associated mass.

• an understanding of the impact on weight when using carry-over parts or systems.

• an early understanding of the impact on weight of different concept and design directions.

Early IntegrationThe earlier and more broadly an OC is

integrated into a development process, the

more efficient the results will be. This rather

simple formula describes the principal of the

success of an OC. Early in the development

process of a vehicle, the engineers are

usually still highly flexible in their design.

This should be leveraged, because at this

stage it is decided if cost and timing, in

relation to the defined functionality and

weight goals, can be kept until later in the

development process. In this phase, weight

management still has every possible design

freedom and can make use of it by applying

the OC and the CAE Weight Management

strategy to reach optimum results. If the

engineers can make reliable predictions

on the system‘s weight and direct weight

savings early, they will be able to save up to

the same amount in secondary weight [2].

The further the process proceeds, the less it

can be positively influenced. The probability

that compromises in function and weight

have to be made, or that the cost or time

frame has to be adjusted, is higher at a later

stage in the development process.

Value of an Optimization CenterWhat is the actual added value an OC brings

to a development process? The benefit

lies within the detailed knowledge of the

Altair ProductDesign is a global productengineering and design company of more than 500 staff. As a division of Altair Engineering, Altair ProductDesign is best known for its market leadership in combining human and computer creativity to fuel innovation, automate processes and develop new methods.

About Altair ProductDesign

The above optimization process of a door at Ford led to a weight reduction of 15%

The earlier and broader an Optimization Center is

integrated into a development process, the more efficient

the results will be.

Altair®, HyperWorks®, RADIOSS™, HyperMesh®, BatchMesher™, HyperView®, HyperCrash™, HyperGraph®, HyperGraph®3D, HyperView Player®, OptiStruct®, HyperStudy®,

HyperStudy®DSS, MotionView®, MotionSolve™, Altair Data Manager™, HyperWorks Process Manager™, HyperForm®, HyperXtrude®, GridWorks™,

PBS Professional®, and e-Compute™ are trademarks of Altair Engineering, Inc. All other trademarks or servicemarks are the property of their respective owners.

Altair Engineering, Inc., World Headquarters: 1820 E. Big Beaver Rd., Troy, MI 48083-2031 USAPhone: +1.248.614.2400 • Fax: +1.248.614.2411 • www.altair.com • info@altair.com

OC team, in a profound prediction of the

consequences of decisions that need to

be made early in the development process

and in the standardized approach of an

OC. Properly applied, the OC will check the

outcome of the options that have to be

evaluated as early as possible and detects

the available weight reduction potential.

All suggestions the OC makes will consider

the robustness of the predictions. An OC

will constantly work with the customer’s

engineering staff to streamline processes.

CAE Weight Management offers an improved

understanding of the development progress,

as the results of the CAE analysis and the

intensive exchange with weight functions

will provide the project management with

predictions concerning performance, cost,

and timing. As the project management

is able to react earlier to erroneous

development directions and can lead

the project into the desired direction,

development risks are minimized.

Real World ExamplesAltair ProductDesign’s OCs have already

been successfully implemented at several

companies within the aerospace industry

including Airbus. Based on these successes,

pilot projects have been carried out in the

automotive industry for clients such as Ford.

The major goal of these projects was the

demonstration of the potential performance

of the first level of integration of an OC.

During the pilot projects, two existing

vehicles (platform F250/350 and Ford

Transit) were analyzed and 50 components

of the F250/350 as well as 12 components

of the Transit have been identified for

further research. To save time and money,

the project was handled in two steps. In a

first step, Altair ProductDesign and Ford

engineers checked

each component for

weight saving potential.

Subsequently, the OC

team created a ranking

system, comparing

the cost and customer

benefits achieved by saving material to the

effort, new tools or production methods

that changes in the design would require.

In a second step, the engineers then

chose which components should undergo

a detailed weight optimization (17 of the

F250/350 and 6 of the Transit).

The team engineers further specified

production and assembly restraints for

these components, before applying the

topology, topography and size optimizations.

A subsequent finite element (FE) analysis

proved that all mechanical functions

concerning strength and stiffness were

unchanged. The result: all in all it was

possible to save an average of 19% weight

for the F250/350 components and 13% of

those from the Transit.

Summary and OutlookTo receive profitable material savings and

to truly meet CO2 emission targets, weight

goals consequently have to be followed up

even more. Based on Altair ProductDesign’s

OC concept, the OEM can be supported to

reach those goals of weight reduction with

several levels of integration. The OC finds the

weight potential in each vehicle, combines

them with the necessary changes of material

and production processes, and

enables the assessment of cost

and value. Especially for existing

weight management functions

at the OEM, the CAE Weight

Management program is a

valuable addition. To truly exploit

the maximum potential of weight reduction

it is important to include the OC as centrally

as possible within the vehicle development

team and to start with the optimization as

early as possible. But even if implemented

at a later point in the development process,

an OC can still deliver significant successes.

The pilot projects at Ford and other OEMs

show that the implementation of even the

first level of an OC can already lead to

double figure weight savings.

References: [1] Lutsey, N., 2010. Survey of Vehicle Mass-Reduction Technology Trends and Prospects. PowerPoint Prsentation, El Monte, California.

[2] Bjelkengren, Catarina, 2008. The Impact of Mass Decompounding on Assessing the Value of Vehicle Leightweighting. Thesis Dual Degree of Master of Science, Massachusetts Institute of Technology.

www.altairproductdesign.com

It was possible to save an average of 19%

weight for the F250/350 components and 13% of those from the Transit.