Emad:
I got the same result: exploding this library part results in short lines instead of arcs. I opened the library part (it is earlier than version 9, the date of the part is 11 March 2000) and the profile is drawn in the 2D Symbol window, and it is composed of lines and arcs. I don’t know why this part explodes into short lines for the arcs. A workaround to get the arcs into your project:
1. Select the part and go to File>GDL Objects>Open Object… (you will get a warning about this object being from an earlier version of ArchiCAD if you are using version 9, click OK)
2. In the main library part window that appears, click on the button next to “2D Symbol”.
3. The 2D Symbol opens with the profile drawn with lines and arcs. Select the Arrow Tool, Select All (Edit>Select All) and copy.
4. Go to the 2D Window or Section/Elevation Window or Detail Window where you want the profile and Paste.
5. The profile will be pasted with true arcs.
I don’t know why this part doesn’t explode correctly, maybe it is due to the complexity of the profile, or that it is from an earlier version of ArchiCAD.
HTH
David