What are the differences between smooth and non-smooth trimming?

There are two methods in trimming, i.e. smooth and non-smooth trimming. In smooth trimming, the boundary element will be cut exactly along the trimming curve; while in non-smooth trimming, the boundary element can be either kept or removed from the model and it will not be cut in half. What is the advantage of each method?

The advantage of smooth trimming is that the boundary of the part will follow the trimming curve exactly. However, it will result in some very bad aspect ratio when the boundary elements are cut. And these bad elements will cause trouble for the later springback analysis.

The advantage of non-smooth trimming is that it will not affect the aspect ratio of the element, and it will not cause extra trouble for the later springback analysis. However, this boundary geometry from this method usually cannot follow the trimming curve. Even though the boundary of the part is not good, it is seen that the spring back prediction is not affected obviously.

For most of the simulation, it is recommended the non-smooth trimming be used.