Impact Damage Monitoring of CFRP Laminated Plate Based on Impact Force Identification

The present paper discusses a structural health monitoring method of CFRP structures based on a impact force identification. In the first part, an experimental identification method of impact force is developed where the relation between force histories and strain responses is determined experimentally. By employing this relation, the impact force is identified for CFRP laminated plates involving impact damages under a drop-weight impact test. It is shown that the identified force history agrees well with the experimental one even when the impact damage is induced. Next, the impact damage monitoring method is proposed. When the information on the maximum impact force is obtained, the occurrence of the impact damage can be predicted easily from the shape of force history, and the damage size can also be estimated using the experimental relation between the damage size and the maximum impact force. Thus, structural health can be evaluated automatically, by monitoring the impact force from the sensor response in real time, and great improvement of the structure safety becomes possible.