D.H. Lammlein PhD Dissertation - Vanderbilt University

A 4500 N axial force is applied evenly over the horizontal surfaces of the tool for
all models and weld process geometry stiffnesses are analyzed. Six offset conditions are
created for each geometry configuration starting from a centered case and moving in
increments of one hundredth of an inch out to 0.05 inches of offset. The centered case is
symmetric about the longitudinal (traverse) weld axis as well as the lateral axis. A
preliminary model was therefore created using one quarter of the tool and two planes of
symmetry for mesh validation and is presented in appendix B. For consistency an
identical mesh seed, shown in Figure 38, was used for all twelve offset and geometry
cases including the laterally centered cases of the two geometries. The geometry cases
differ in the treatment of the boundary condition in the corner region. The standard
model contains approximately 75,000 nodes and 430,000 4-node tetrahedral elements.
For each case, the maximum advancing side and retreating side deflection
magnitudes were found in the simulated aluminum weld material. Plots of maximum
deflection versus lateral offset are presented in Figure and Figure for the tracked case
and the untracked case respectively. An equivalent range is used for the y-axis of each
graph to allow for comparison of the tracked and untracked geometry cases.
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