Retrofitting scheme and experimental research of severally damaged carbon fiber reinforced lattice-core sandwich cylinder

To improve the reutilization of advanced carbon fiber reinforced composite (CFRC) lattice-core sandwich cylinder (LSC), a severely damaged LSC was retrofitted by CFRC laminate through wrapping and riveting schemes. Free vibration and uniaxial compression experiments were carried out to reveal its mechanical performances. Natural frequencies and vibration modes of the repaired cylinder are close to the intact cylinder. Compared with the stiffness of the intact cylinder, 98.7 kN/mm, stiffness of the repaired cylinder is 138.83 kN/mm, even a little stiffer. Failure of the repaired cylinder locates at the lower end. Initially, the inner skin delaminated from the core and finally fracture of the outer skin made the cylinder out of work. The repaired segment is not damaged. Ultimate load of the repaired cylinder is 377.38 kN, only a little smaller than of the intact cylinder. The retrofitting scheme is effective to re-utilize the severally damaged CFRC LSC.