The invention discloses a DIC-(
Digital Image Correlation)-technique-based curvature
modal damage recognition method. The method comprises the following steps of S1, applying a dynamic hammer excitation to a model of a truss structure, shooting an initial truss structure and the truss structure, to which the hammer excitation is applied, respectively by utilizing a DIC technique, so as to obtain time-sequence images of the deformation of the truss structure, meanwhile, measuring time-interval signals of the hammer excitation by utilizing a dynamic and static acquisition instrument, so as to obtain an exciting force curve, and carrying out
correlation analysis treatment on the time-sequence images, so as to obtain a displacement curve; S2, enabling the obtained displacement curve and exciting force curve to correspond in accordance with a time order, importing into a dynamic
signal test and analysis
system, so as to obtain a
frequency response function, and deriving the inherent frequency and the vibration
modal of the truss structure according to the
frequency response function; and S3, after the inherent frequency and the vibration
modal are obtained, acquiring a difference value by using curvature modals to obtain a difference-value index of the curvature modals, and determining a difference between the curvature modals, before and after the deformation, of the truss structure, so as to judge whether the damage is generated to the truss structure, to position the damage and to judge the extent of the damage.