Case Study D

E-coat Paint Process Simulation using Finite element analysis

Case Studies
The following case studies are meant to be representative of the many different types of investigative work that can be accomplished by Finite Element Analysis (FEA) with the Parametric Module. These include examples from rocker panel design optimization to visualization of the E-coat paint process in operation.

Several PC work stations were used to create and run simulations for the case studies, including a Dual Intel Xeon 3.06 GHz PC with 4.5 GB RAM and an Intel Pentium 4 3.06 GHz with 1.5 GB RAM.

The typical elapsed time per iteration was related as a function of the total number of elements and the number of Boundary Conditions. The range of time required for one iteration varies from < 20 seconds for the simpler models to as much as ~25 minutes for the larger ones.

Case Study D:
Can the Existing E-Coat Tank Design Adequately Paint a New Automotive Body Design?

A passenger car plant wants to evaluate the impact of the addition of an SUV to their product mix. They have already spent $7 million changing the conveyor system to accommodate the larger profile of this vehicle, and they are now concerned the existing E-coat paint system is undersized. Goals of the study are to: simulate the larger vehicle in the E-coat tank (designed for medium sized 4-door passenger vehicles); and investigate the E-coat thickness in the more complicated rocker panel of the SUV.

Present voltage profile

Situation
140 second dwell time, which is adequate for passenger cars now.

E-coat tank already has Side, Roof, and Floor ME Cells.

Model
Only ½ of the SUV was modeled due to the longitudinal axis symmetry plane, since it is unnecessary to create two matching sides. This model is a cross-section of the SUV's body, created in a 2D format and then extended into a pseudo-3D model. The advantage of this approach is quick model preparation and extremely fast solution times. (Note this model also includes a very deep recessed region and so it will simulate current to flow into the region just like an actual 3D model would, but without the complexity and longer solution times.) The adjusted parameter in the second simulation run was elapsed time. Therefore, no changes were made to the geometry or the high voltage BC's of the model.

140 seconds deposition time	160 seconds deposition time

Results
The model was run under the standard conditions for the passenger car. The simulation revealed a low film thickness in an internal recessed area of the SUV. The next simulation was run for 20 seconds (~15%) longer and then E-coat film thickness in this same region was increased to above 13 µ, which was set as the global minimum.

Conclusions
The simulation results predicted that the existing E-coat tank was most likely too short to accept the SUV. This test would have been impossible to do physically, because it would have required the plant to slow down the production line to accommodate the SUV, hurting output. Seeing the uneven film distribution of the SUV, the plant has decided to extend the length of the E-coat tank to increase the capacity in order to handle the larger body.

Case Study A    |    Case Study B    |    Case Study C    |    Case Study D    |    Case Study E    |   Case Study F