Body-flexibility Methodology for Driving Dynamics

Siemens PLM Software
LMS Engineering services
Body-flexibility methodology for
driving dynamics
Gaining insight into the relationship between body stiffness and vehicle handling
Benefits
• Provide insight into the
relationship between body
stiffness characteristics and
vehicle performance
• Visualize body deformation
during handling maneuvers
• Improve the body targetsetting process
• Balance the conflict
between vehicle handling
and NVH performance
• Improve driving dynamics
by targeted structural body
design modifications
• Relate the subjective
driver feeling to objective
measures
Summary
LMS™ Engineering services has developed
a method that provides more insight into
the relationship between body stiffness and
driving dynamics. It enables you to better
balance the conflict between handling and
noise, vibrations and harshness (NVH)
performance earlier in the development
process.
Although test and simulation technologies
for suspension development for driving
dynamics are well established, body design
and body target setting for vehicle handling
performance are more complex.
Reinforcements for better driving dynamics
are often applied based on experience or by
trial-and-error. This can cause expensive
body design changes late in the vehicle
development process, which can result in
production delays and increase costs. LMS
Engineering experts have developed a
unique test-based methodology that
provides insight into the relationship
between body stiffness characteristics and
vehicle performance.
Car body flexibility influences the handling
performance, including the subjective
driving experience. Traditional approaches,
such as body static stiffness tests, can
objectively quantify the effect of reinforcements into a single static stiffness value.
But when evaluating on the track in operational conditions, real objective global
vehicle performance quantities, such as
yaw-rate, lateral acceleration or roll angle,
are typically difficult to directly relate to
body stiffness changes.
As these performance indicators result from
the combined effect of all forces between
suspension and body, individual contributing body forces can change in relevant
amounts, while the combined effect can
still be small. Insight into these force mechanisms is crucial for studying different body
www.siemens.com/plm/lms
LMS
LMS Engineering services
Body-flexibility methodology
for driving dynamics
variants. Therefore, carmakers are looking
for technologies that provide a better
understanding of the relation between
body flexibility and handling performance.
LMS Engineering has developed a unique
test-based technology that enables you to
visualize body deformation during handling
maneuvers, and decompose it into contributions of global body deformations, such
as body torsion and bending, and local
body deformations. This methodology can
also be used to improve the body stiffness
target-setting process, allowing engineers
to better balance the conflict between
handling and NVH performance while
designing a next-generation lightweight
platform.
A typical body flexibility project is
comprised of the following phases:
Identification of contact forces
In the first phase, the individual timedomain forces in the connection points
between suspension and body are
identified. This is done using the matrixinversion method based on strain-gauge
measurements.
Body strain measurements.
Body deformation during maneuver.
Investigation of body deformation
In the second step, the identified timedomain loads are combined with a modal
model of the trimmed body to visualize
body deformation during handling maneuvers. This deformation can be decomposed
into contributions of global body deformations, such as body torsion and bending,
and local body deformations.
Targeted improvement of the
body design
The results identify weak body areas, and
show where structural modifications can
be more effective. They allow setting body
stiffness targets and applying efficient
modifications while considering the call for
lightweight vehicles.
Contact
Siemens PLM Software
Americas
+1 248 952 5664
Europe
+32 16 384 200
Asia-Pacific +852 2230 3308
www.siemens.com/plm
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