GSD's on Plane Panel Plate Parts

The GSD:s are first placed in their nominal position, that means, in the position they should have had if shrinkage could have been neglected entirely. The effect of the shrinkage compensation is that the geometry will be enlarged so that the part after assembly will have its correct geometry. The GSD:s will be affected by this geometry modification like all the rest of the part.

Some consequences of the principle above:

• Along a seam for butt welding with gap the tip of triangles will be in the "gap zone", for example, the tip will be cut by the burner. See the figure below.

• The same is true for the end of a line marking. The end in the "gap zone" will be cut by the burner. See the figure below.

  

  Figure 2:1. GSD:s in "gap zone".

• Similarly, triangular GSD:s can be used for positioning of two plates relative to each other by checking the distance between them. The effect is also that this distance after welding will be less due to the shrinkage.

• The outer geometry of the plate part will be in the nominal position after welding.

If there is excess in the panel the GSD will be placed as though there had not been any excess, that means, in the nominal position.

In general, marking traces are either entirely replaced by a number of GSD:s or the marking traces may be supplemented with GSD:s.

The distance between adjacent GSD:s along a trace that has been replaced entirely by GSD:s must not exceed the distance given by the default parameter MAXDIST. The "inner" GSD:s will be equally spaced and triangular GSD:s is facing towards the center of the marking trace.

Short marking traces may be represented by both GSD:s at the ends and the actual trace curve to avoid confusion. This will occur when the length of the marking is shorter than the distance given by the default parameter TRACE_LIM. By setting a very large value to this parameter one will get the result that all traces will be marked. If the trace is wanted there will not be any "inner" GSD:s.

GSD:s are not added at all to marking traces with a length less than three times the value of CORNER_DIST. The figure below shows complete marking information for a stiffener with different parameter settings (triangular GSD:s used).

Figure 2:2. GSD:s along Marking Trace.

It should be noted that in some circumstances large parts of a GSD along an edge may be removed (or even disappear entirely) for example, in case of beveling, especially if combined with chamfer. In such a case the marking will have to be amended or added by the workshop. See the figure below.

Figure 2:3. GSD in Chamfer Area.

The following paragraphs describe the different positions where GSD:s are evaluated, in most cases quite automatically.