AUTOMOTIVE PLASTICS CAE Dr. Jay M. Mahishi
There are a number of analysis
tools available to perform FEA of plastic components. But to perform CAE of these
components requires understanding of the plastic materials and the applications.
Plastics offer an innovative way of reducing weight and cost by parts
consolidation, ease of manufacturing over metals but they pose several
engineering challenges.
The first secession will discuss
the CAE challenges and analysis approaches
SESSION 1 GENERAL ENGINEERING CHALLENGES 8am-12.00
STIFFNESS
AT EXTREME TEMPERATURE
It is important to identify whether the part is stiffness or
strength critical. Some components require that
the deflection does not exceed a certain limit from functionality or from
vibrational point of view.
Most plastics considerably loose their material stiffness at higher temperature.
STRENGTH
AT EXTREME TEMPERATURE
The maximum stress is critical in many components that are supporting
direct loads.
Break 9-50am-10-10am
THERMAL
/ MOISTURE STABILITY
A number of plastic components that meet the strength and
stiffness requirements fail in buckling that is
often not validated
DURABILITY
Failure of plastics is different from metals and requires
different approach
ENERGY
ABSORPTION/CRASHWORTHINESS
Plastics provide excellent energy absorbing counter measures
for occupant safety during crash
SESSION 2
ANALYSIS APPROACHES FOR DURABILITY
LINEAR/NON-LINEAR
STATIC
Almost all plastics have a non-linear stress strain curves,
but a linear analysis may be performed for initial sizing
LINEAR/NON-LINEAR
THERMAL
It is critical to validate at extreme temperature using
appropriate material stress strain curves. In case of constrained parts the strains due to thermal expansion should be
included. In some of the HVAC application the temperature
gradient also becomes critical
VISCO-ELASTC/PLASTIC-
CREEP
Plastics are viscoplastic and require appropriate validation
Break
CASE STUDIES
SERVO
MOTOR BRACKET Under the hood component that is
subjected to static, dynamic, thermal loading
SIDE
MIRROR HOUSING
SEAT
COVERS
CONSOLE
SESSION 3
ANALYSIS APPROACHES FOR NVH 8am-12.00
DYNAMIC
NATURAL
Special attention is required in deciding stiffeners and
bosses and attachment points
DYNAMIC
FORCED
The interior plastics significantly contribute to the interior
acoustics
SQUEAK
AND RATTLE
Requires evaluation of Modal interferences
Break 9-50am-10-10am
CASE STUDIES
INSTRUMENT
PANEL
SIDE
MIRROR HOUSING
BACK
PANEL
SESSION 4
ANALYSIS APPROACHES FOR CRASH
CRASH
AND OCCUPANT SAFETY
(FRONT, SIDE, REAR, HEAD IMPACT, PEDESTRIAN IMPACT)
Occupant injuries index can be significantly reduced by CAE
of the Interior Plastic components that come
in contact with the occupant during crash
OPTIMIZATION
Break
CRASH CASE STUDIES
KNEE
BOLSTER FRONT IMPACT
DOOR
TRIM SIDE IMPACT
A-PILLER,
ROOF HEADLINER FOR HEAD IMPACT
OPTIMIZATION CASE STUDIES
HEAD
LINER COUNTER MEASURE