NASA/ TM-1999-209097 ARL-MR-439 Testing and Analysis of Composite Skin/Stringer Debonding Under Multi-Axial Loading Ronald Krueger and Michael K. Cvitkovich Langley Research Center, Hampton, Virginia T. Kevin O'Brien U.S. Army Research Laboratory Vehicle Technology Center Langley Research Center, Hampton, Virginia Pierre J. Minguet Boeing, Philadelphia, Pennsylvania February 1999