Component Test Division -Unconfirmed Minutes

April 19, 20 & 21, 1999 DaimlerChrysler - Auburn Hills, MI

Tuesday, April 20, 1999 - Divisional Progress Meeting

Raj Thakkar began the meeting at about 9:45 a.m. The minutes from the meeting held October 20, 1998 in Bloomington, MN were approved.

Raj briefly mentioned the Digital Prototype (ATV) special meeting that took place the day before. Separate minutes will be issued for that meeting. Anyone who is interested in the project data compiled thus far can visit the FD&E web site or contact Dan Klann, Christoph Leser, or Kurt Munson. One particular issue that was revisited from the ATV meeting was the level of displacement used during bushing tests. There was concern that greater displacement may be needed to characterize the highly nonlinear behavior of the bushings.

The first of the two technical presentations during the divisional progress session was from Venkata Nambori of DaimlerChrysler Jeep and Truck Engineering, on "Full Vehicle Fatigue with Real Time Road Loads: Analysis and Correlation." His co-authors were Gamal Alghanem and Ram Bhandarker, also from JTE. The FE model of the chassis structure used 32 suspension loads as input for an inertia relief solution. Batch programs were used to help speed up road load data management in dealing with such issues as spikes, polarity, schedule definition, static load inclusion, etc. The FE model was subjected to both stress analysis and fatigue prediction. Two areas of the frame were checked for correlation between analysis and testing. Although the loading is quite obviously multiaxial, only about 2% of the critical areas on the frame showed multiaxial stress behavior.

The second presentation was by Mark Pompetzki of LMS on "FEM-Based Durability Analysis of an Automotive Knuckle." The knuckle was subjected to a 3-DOF test. The loads were collected via a wheel force transducer. The analysis used quasi-static superposition and elastic "pseudo-stress." The multiaxial fatigue analysis used a critical plane approach, with damage calculated on planes in of ten-degree increments. Predicted life was within 20-25% of actual life. Several special techniques were used in the analysis, especially for saving time. "Nodal elimination" and a "rainflow projector" were among the techniques employed, the latter helping to produce a reduced load history. The reduced history was run on the full FE model, and once the critical locations were found, those were, in turn, subjected to the full history.

Copies of the overhead material from these presentations are attached to US Mail minutes to provide further detail.

Wednesday, April 21, 1999 - Divisional Planning Meeting

Paul Lubinski began the meeting at about 1:00 p.m. During Monday's Digital Prototype for Durability special meeting, several people volunteered to help out with action items required for the near future. Other ideas, items, and volunteers came forward during this planning meeting. The following is a summary of all those items and volunteers.

Finding and posting part numbers: no volunteer for this activity at this time. This issue may be somewhat alleviated if we purchase a large enough number of parts at a given time to have them on hand for anything and everything the project requires of them. Caterpillar has provided Darrell Socie with funding for 20 frames; he would like to increase that total to 30. Funding would still be required for the additional 10 frames, plus a suitable number of control arms and shocks. Al Conle will check if Ford can provide additional funding.

Continuation of FE modeling: Mark Pompetzki, Tom Cordes, and Al Conle will see what they can do. Tom will find out if someone is interested in trying the rig-input data in the model. Al will find out if anyone at Ford is interested in helping out.

Rigid body modeling: Ric Mousseau will champion performing this task in Carsim. He expects to have the work completed, with results available to the committee, by this fall's meeting.

Mass/inertial properties: at the fall 1998 meeting, continued work in this area was suggested for the frame and the combination of frame and powertrain. The topic did not come up in the spring meetings. Do we have all the data we need?

Flexible body modeling: Doug Peterson will check if MDI can contribute to continued ADAMS modeling.

Tire testing: Darrell suggested that MTS might be able to help in this task with their equipment. Special thanks goes to Ralph Stephens for finding Will Mars and Kelly Donaldson in other meeting rooms so they can get together to discuss a plan. They will specify the requirements, and Kelly will contact his colleagues regarding scheduling and other logistics.

Bushing tests: Need a decision ASAP on whether to redo radial tests with greater displacement. Need parts for control arm bushing tests? Need funding for the tests.

Modal testing: no volunteer. It is assumed we still need this work (?).

Improvements to web site: anyone with suggestions should contact Christoph Leser or Dan Klann.

If anyone is interested in volunteering wherever the project tasks require them or if there are any questions, please contact Raj Thakkar or Paul Lubinski as soon as possible.