Optical non-contact strain test method in internal pressure structural strength test of filament wound shell

Scattered spot was formed on the surface of the filament wound casing by spraying method and marker pen point method respectively. The optical non-contact strain measurement was carried out on the shell during the internal pressure strength test, and the strain data measured by the traditional strain gauge method was used. The comparison shows that the relative error of the data measured by the two methods is between 0.29% and 9.7%, which is consistent with the variation of the filament wound shell in the same circumferential direction. It confirms the feasibility of strain testing, and reveals that the optical non-contact strain test method should be applied to the filament wound shell.