| GM is expanding its in-house expertise
with a new virtual clutch development model (VCDM). The OEM wants more
involvement in clutch design using simulation from the start to improve
quality and reduce timescales.
GM Powertrain group manager system analysis Lina Lundquist said: “Working
in-house is also cheaper and will contribute to our strategy of moving
from road testing to lab testing to mathematical analyses.”
Suppliers have responsibility at present, while the OEM focuses on the
application and test work. But even when asked to, suppliers haven’t
always used simulation during development and may only provide sub-assemblies,
not the entire clutch module. GM hasn’t always performed simulations
either, trusting this to the suppliers. The fragmented process left GM
Powertrain wanting its own analysis tool.
VCDM is a 1-D simulation comprising engine, gearbox, driveline, and suspension.
The tool makes analysis of clutch characteristics such as judder, driveline
resonance, idle rattle, engine stop and load reversal “clonk”
easier.
Simultaneous analysis of these areas up-front helps optimise parts before
any hardware is tested. Checking design changes is simpler and clutch
models for new vehicles are easily created.
Results are displayed in Excel to make information easy to present and
share. Each clutch performance criterion is given objective and subjective
ratings, displayed on a spider chart.
VCDM will later include other potential failure modes such as thermal
loads.
© Automotive Engineer, 2008
|
|
