Abstract: A method of making a fiber reinforced composite material having a two-part liquid solution forming magnetic nanoparticles. The method includes the steps of preparing a fiber reinforced composite having dispersed fibers and a polymer matrix and having a plurality of vascular channels therethrough. A first liquid solution is incorporated in at least one of the vascular channels and a second liquid solution is incorporated in at least one other of the vascular channels. When the liquid solutions are joined together because of damage or cracking to the composite, the liquids form a ferrous magnetic material. Non-destructive evaluation of internal damage to the fiber reinforced composite material may be accomplished by magnetic field disturbance detection, thermal detection, or visual detection.