Output-Only Damage Detection in Plate-Like Structures Based on Proportional Strain Flexibility Matrix

Area of Science:

• Structural Engineering
• Mechanical Engineering
• Materials Science

Background:

• Strain flexibility-based methods are common for structural health monitoring.
• Existing methods require complex mass-normalized strain mode shapes (SMSs), which are difficult to obtain with unknown excitation.
• The applicability and robustness of current methods need enhancement.

Purpose of the Study:

• To develop a novel damage index for plate-like structures.
• To overcome the challenge of obtaining mass-normalized strain mode shapes (SMSs) in output-only scenarios.
• To improve the robustness and applicability of strain flexibility-based structural health monitoring.

Main Methods:

• Development of a new damage index based on uniform load strain field (ULSF) differences.
• Introduction of a proportional strain flexibility matrix (PSFM) and its simplified construction.
• Integration of PSFM into ULSF estimation for output-only damage detection.

Main Results:

• The proposed method successfully identifies damage at various locations and degrees.
• Numerical and experimental validations confirm the method's accuracy.
• The technique effectively detects damage without requiring SMS estimation.

Conclusions:

• The novel damage index and PSFM offer a reliable approach for output-only damage detection in plate-like structures.
• The method simplifies structural health monitoring by eliminating the need for complex SMS.
• This research contributes to more robust and applicable structural health monitoring techniques.