Help with automotive static load cases
Help with automotive static load cases
(OP)
I have recently hired a new stress analyst. His first task was to evaluate an UCA. We have ADAMS static loads (typical DELPHI static loads like 3g 3g, 6g one side, braking, lateral ...).
I did it myself as an inertial relief problem and created 11 load cases, one for each static load. The ADAMS loads are applied at the bushings and ball joint.
When the new guy did it he created 33 load cases. He separated each of the three loads for each ADAMS load case into its own load case.
He claims this is a worst case analysis but I don't see how this can be done as each load case requires all three loads for equilibrium.
Have any of you heard of doing it this way?
Thanks.
I did it myself as an inertial relief problem and created 11 load cases, one for each static load. The ADAMS loads are applied at the bushings and ball joint.
When the new guy did it he created 33 load cases. He separated each of the three loads for each ADAMS load case into its own load case.
He claims this is a worst case analysis but I don't see how this can be done as each load case requires all three loads for equilibrium.
Have any of you heard of doing it this way?
Thanks.





RE: Help with automotive static load cases
Ed.R.
RE: Help with automotive static load cases
The problem arises with the inertial relief. The constraint of the control arm is not really its own inertia but the resolved forces at the bushings. The inrel is only there to take care of the small imbalance in forces.
I will need himi to further explain the concept.
RE: Help with automotive static load cases
RE: Help with automotive static load cases
With regards tot he number of load cases your analyst is right, and so are you, depending on exactly how those loads were created.
I would rather not use inertia relief to provide equilibrium, I would use load sets that are correctly constrained at each joint, albeit with an inertial term if necessary. I have back calculated all this in ADAMS and it works correctly (not surprisingly).
Cheers
Greg Locock
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