Use of laser shock waves to test piezochromic coatings for impact detection

The design of piezochromic pigments is a promising way to adjust smart painting and therefore to develop a "visual" impact detection coating. This paper deals with the possibility to use laser shock waves to test piezochromic coatings for impact detection. For that purpose, an experimental setup was developed in order to obtain compressive load in the coating thanks to the impedance mismatch between selected materials. An analytical modeling was used to validate the proposed method. The experimental investigation coupled with finite-element modeling on four smart coatings showed that these coatings can reveal impact location by a significant change of color if a relevant pressure threshold is reached. The results presented in this work are promising and demonstrate the ability of the proposed laser shock method for characterizing the pressure thresholds of piezochromic smart paintings. It opens the door for studying future smart paintings with different critical pressure levels, depending on the targeted application. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)