Abstract
Damage identification methods using vibration data have attracted attention as health monitoring systems of composite laminated structures. In many papers referred to damage identification methods using vibration data, damage is modeled in stiffness degradation regardless of damage modes. In health monitoring of real structures, identifying size and location of slight delamination, which accompany matrix cracks, is important. However, the relationship between the change of natural frequency caused by stiffness degradation and those caused by actual delamination is unknown. Then, unconfirmed applicability of damage identification method with stiffness degradation model to identifying delamination would be introduced. In the present study, the relationship between stiffness degradation and delamination is investigated in terms of factors that control the natural frequency changes of the structures by using FEM. Applicability of damage identification method to delamination identification is also examined.
