D.H. Lammlein PhD Dissertation - Vanderbilt University

procedure ensures that process force variations are not somehow related to transient
heating effects or some unforeseen longitudinally varying factor. Figure 32 shows solid
block data from these trails. No observable trend can be seen in the process forces.
Figure 32: Process forces and lateral offset for two separate welds using the untracked
clamp geometry.
In Figure 32, the period between 40 and 70 seconds immediately follows the
dwell period of the weld and transient effects are seen. The final 5 to 10 seconds of each
weld are affected by the ending of the weld plate. Figure 33 represents the most useful
portion of the solid block data, and again shows no useful trend in the untracked case.
Figure 34 shows data from a weld made using the tracked geometry. The data seen for
the tracked data shows useful force changes with corresponding changes in lateral
position.
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