When I trimmed the mesh after forming, I only used one trim curve (in IGES format), but LSDYNA found 10 trimming curves. Accordingly, the result was not acceptable. What was the problem?

It is found that when there are multiple semicolons (;), then the IGES file contains multiple trimming curves. Even though these lines seem to be a closed curve, however, they are separate, and it is inappropriate to trim the mesh with separate curve. Try to avoid the semicolon in the IGS file when necessary if you only have one self-closed trimming curve.