Hi
Mechanical APDL no longer supports pre-processing of LS-Dyna models. Plus the element types that support layering in MAPDL differ in how the data is stored versus the LS-Dyna shell element. Lastly back when MAPDL did support pre/solve/post of LS-Dyna models composites were not supported. So you would usually create the k file in MAPDL then use LS PrePost to finish off the set up. I'd recommend using Workbench LS-Dyna. For very complex layerings WB ACP supports WB LS-Dyna.
Mike