A polymer-matrix fiber-reinforced composite structure includes a plurality of polymer composite layers having at least one polymer composite layer that includes a first polymer-matrix and a first fluorescent agent interspersed through the first polymer-matrix. Damage to the polymer composite structure results in a change in fluorescence at the point of damage. A method for detecting damage in the polymer composite structure described above including the steps of applying light having a wavelength selected to induce fluorescence in the first fluorescent agent to the polymer composite structure, detecting a detected fluorescence pattern, and comparing the detected fluorescence pattern to a predetermined normal fluorescence pattern.