TY JOUR TI Methods and means of acoustic emission diagnostics of power elements of the airframe of aircraft KW appraisals structural strength KW aircraft engineering KW acoustic emission KW crack resistance KW invariants JO NDT World AU Popov, A.V. AU Komlev, A.B. AU Samuylov, A.O. AU Zakusilov, P.V. PY 2021 IS 24 PB LLC SVEN