Absolute Displacement-Based Formulation for Peak Inter-Story Drift Identification of Shear Structures Using Only One...

Area of Science:

• Structural Engineering
• Seismic Analysis
• Vibration Monitoring

Background:

• Estimating seismic response in multi-degree-of-freedom (MDOF) structures typically requires numerous sensors.
• Conventional methods using single accelerometers are often unstable, especially when considering higher modes.
• Obtaining higher mode parameters from structures under low excitation is challenging.

Purpose of the Study:

• To develop a stable and accurate method for estimating seismic displacements and inter-story drifts using a single accelerometer.
• To overcome the limitations of conventional methods and the difficulty in obtaining higher mode parameters.
• To validate the proposed approach through numerical simulations and experimental testing.

Main Methods:

• Converting recorded absolute acceleration to absolute displacement.
• Formulating a state-space equation for analysis.
• Utilizing only the first two modal parameters for estimation.
• Conducting numerical simulations on a nine-story structure.
• Validating the approach with a physical experiment.

Main Results:

• The proposed method accurately estimates time histories of relative displacements and maximum inter-story drifts using only one accelerometer.
• The approach is robust against environmental noise.
• Numerical simulations confirmed the applicability and identified optimal accelerometer placement.
• Analysis revealed the limited impact of higher modes when using the proposed method.

Conclusions:

• A single accelerometer can reliably estimate seismic response parameters (relative displacements, inter-story drifts) in MDOF structures.
• The proposed state-space formulation effectively overcomes the instability issues of conventional single-sensor methods.
• The method's robustness and accuracy, even with limited modal information, offer a practical solution for seismic structural health monitoring.