an optical fiber sensor for detecting curvature of a body / structure comprises a cladding having an outer periphery . a central core receives and transmits light . the central core has bragg gratings and is positioned in neutral planes of the cladding . peripheral cores receive and transmit light . the peripheral cores have bragg gratings and are peripherally positioned in the cladding with respect to the neutral planes . a connection configuration is provided in the outer periphery of the cladding to attach the optical fiber sensor to a body / structure such that the central core and the peripheral cores are in a predetermined orientation with respect to the body / structure to measure curvature of the body / structure .