Title :
Detecting defects in adhesion between a metal hemisphere and a polymer base
Author :
Salmi, Ahmed ; Heino, O. ; Nieminen, H.J. ; Salmi, T. ; Karppinen, Pasi ; Patola, T. ; Haeggstrom, Edward ; Hacking, S.A.
Author_Institution :
Dept. of Phys., Univ. of Helsinki, Helsinki, Finland
Abstract :
Detecting localized defects in adhesion on a spherical shell is challenging, especially if one has access only to its rim. Our group previously quantified the spatial average of the adhesion between a metal hemisphere and a polymer base [1]. Here we report on progress towards determining the presence of localized defects, their position, size, and strength. Tests were performed on a 5 cm diameter metal hemisphere attached to a UHMWPE (Polyethylene, PE RCH 1000 D150×2000 Etralene) base. Defects in adhesion were generated by machining hexagonal holes (5 to 17.5 mm) into the polymer base prior to fixing by adhesive. These known areas without adhesion were remotely characterized with a guided ultrasonic wave (Lamb quasi-modes) generated by a Nd:YAG (1064 nm, 8 ns pulse duration) pulse from one rim of the shell and detected with a laser Doppler vibrometer. We detected the presence and position of the defects.
Keywords :
adhesion; metals; polymers; surface acoustic waves; ultrasonic materials testing; Lamb quasimodes; Nd:YAG pulse; UHMWPE; adhesion; defect position; defect size; defect strength; etralene; guided ultrasonic wave; hexagonal holes; laser Doppler vibrometer; localized defect detection; machining; metal hemisphere; polyethylene; polymer base; size 5 cm; size 5 mm to 17.5 mm; spherical shell; time 8 ns; wavelength 1064 nm; Acoustics; Adhesives; Cavity resonators; Measurement by laser beam; Polymers; Steel; adhesion; guided acoustic waves; hemisphere; ultrasound;
Conference_Titel :
Ultrasonics Symposium (IUS), 2013 IEEE International
Conference_Location :
Prague
Print_ISBN :
978-1-4673-5684-8
DOI :
10.1109/ULTSYM.2013.0179
