The fatigue test article is cycled to duplicate near max loadings of takeoff- cruise- landing- pressurization /depressurization cycles as in commerical service. Not expected to fail wings or any other parts but to find and if needed to correct structural issues resulting from many service cycles . And yes- includes routine inspection cycles.
It is NOT the same test structure used in static test
" But outside the building was the 767 test article in the fatigue test rig. Over and over, the wing was flexed to the cert limit, then relaxed back to unload it. It didn't break while we were there, and I'm sure they interrupted the test every couple hundred cycles for routine inspection."