Complex sentence: He married former supermodel Elaine Irwin Mellencamp on September 5,1992, but on December 30,2010, Mellencamp announced that he and Irwin had separated after 18 years of marriage.
Split into simpler sentences: He married former model Elaine Irwin Mellencamp on September 5,1992. On December 30,2010, Mellencamp announced that he and Irwin had separated after 18 years of marriage.