TY JOUR TI Impact Induced Damage Detecting of Aircraft CFRP Covering by Acoustic Testing KW CFRP carbon-fiber reinforced plastics KW impact induced damages KW ultrasonic KW transducers with the dry point contact KW Lamb waves JO NDT World AU Samokrutov, A.. AU Shevaldykin, V.. PY 2015 IS 19 PB LLC SVEN