It is shown that there exist initial cleaning threshold,complete cleaning threshold and substrate damage threshold of laser power density for laser beam to remove the paint layer,.

With the aim to improve the application of polyvinylidene fluoride(PVDF) films for surface-strain sensing of ship and marine structures,we developed an experiment method for the strain sensing by using an electrostatic voltmeter of non-contact type to detect inductive charges on the PVDF film,which was covered by paint coating of the structure.