Damage Detection in Steel-Concrete Composite Structures by Impact Hammer Modal Testing and Experimental Validation

Area of Science:

• Structural Engineering
• Materials Science
• Non-Destructive Testing

Background:

• Steel-concrete composite structures offer high strength-to-weight ratios for mid- and high-rise buildings.
• These structures are vulnerable to damage from construction flaws, design errors, corrosion, and concrete shrinkage, which can reduce overall strength.
• Effective damage detection is vital for maintaining structural integrity and safety.

Purpose of the Study:

• To develop and validate a damage detection strategy for steel-concrete composite structures.
• To identify regions of stiffness variation without requiring a baseline model of the undamaged structure.
• To quantify stiffness reduction using mode shape curvature changes.

Main Methods:

• Utilized an impact-hammer-based modal testing procedure.
• Developed a mathematical formulation to identify stiffness variations.
• Adopted changes in mode shape curvatures as a criterion for stiffness reduction.
• Generated a stiffness variability index based on 2D mode shape curvatures to create a damage distribution pattern.

Main Results:

• Numerical predictions successfully correlated with experimental data from a full-scale steel-concrete composite beam.
• The method accurately identified stiffness variations indicative of damage.
• A damage distribution pattern was successfully generated.

Conclusions:

• The proposed damage detection strategy effectively identifies stiffness reduction in steel-concrete composite structures.
• This approach provides insights into failure mechanisms, aiding in the development of safer infrastructure.
• The method's validation with experimental data confirms its reliability for practical applications.