There was a similar thread on more or less the same topic. This is part of what I wrote there:
“Many gedolim of recent and ancient times have had two names. Among them are the Tur (13th century), the Kli Yakar (16th century), the Minchah Belulah (16th century), the Baal HaTanya (18th century), the Degel Machane Efraim (18th century). Not only did Rav Elyashiv have two names, but at least one of his own children did (probably more — I just couldn’t find their names).”