Output-Only Modal Identification of Civil Engineering Structures Based on Parametric Complexity Pursuit

Area of Science:

• Structural dynamics and modal analysis
• Civil engineering applications
• Vibration analysis

Background:

• Modal identification is crucial for assessing structural health and performance.
• Existing output-only methods face challenges with high damping and closely spaced modes.
• The complexity pursuit (CP) algorithm offers a basis for modal identification.

Purpose of the Study:

• To introduce a novel parametric output-only modal identification method (PCP).
• To enhance accuracy and robustness in modal parameter identification for civil engineering structures.
• To address limitations of conventional methods in scenarios with high damping and closely spaced modes.

Main Methods:

• Extension of the complexity pursuit (CP) algorithm into a parametric formulation (PCP).
• Global identification of all modal parameters by accounting for inter-modal influences.
• System representation within a rigorous theoretical framework aligned with structural dynamics.

Main Results:

• PCP demonstrated consistent identification accuracy across all damping levels, proving damping-independent.
• The method effectively identified closely spaced modes, a challenge for conventional CP.
• Numerical simulations and application to the HCT building confirmed PCP's practical effectiveness and superiority.

Conclusions:

• PCP provides a robust and theoretically grounded framework for output-only modal identification.
• The parametric approach enhances accuracy and robustness, particularly in challenging conditions.
• PCP offers superior modal separation and identification accuracy compared to existing techniques.