Yes, there are Global Entry kiosks at IAD. As soon as you enter the customs/immig area, the kiosks are on the far left side against the wall. Sometimes there is a metal bar blocking the entrance lane to the kiosks. Simply move the metal bar - to open it - and then head straight to the kiosks.

Unfortunately there is no Pre-Check at mid-field after you have cleared customs/immig and are going through security.