Verification of a Stiffness-Variable Control System with Feed-Forward Predictive Earthquake Energy Analysis

Area of Science:

• Structural Engineering
• Seismic Mitigation
• Control Systems

Background:

• Semi-active isolation systems with controllable stiffness are crucial for seismic mitigation.
• Existing systems are more effective for far-field than near-fault earthquakes.
• A comprehensive system is needed for both near-fault and far-field seismic events.

Purpose of the Study:

• To propose a new algorithm, Feed-Forward Predictive Earthquake Energy Analysis (FPEEA), for seismic response reduction.
• To identify ground motion characteristics and optimize energy balance for reduced seismic impact.
• To develop a system offering comparable seismic response reduction for diverse earthquake types.

Main Methods:

• Developed the Feed-Forward Predictive Earthquake Energy Analysis (FPEEA) algorithm.
• Considered seismic velocity spectrum energy distribution and optimized kinetic/potential energy balance.
• Utilized a two-degree-of-freedom structure for numerical simulations and shaking table tests.

Main Results:

• FPEEA significantly suppressed isolation layer displacement, outperforming other control methods.
• FPEEA demonstrated superior control over superstructure acceleration.
• Shaking table tests confirmed the algorithm's satisfactory performance in reducing both displacement and acceleration.

Conclusions:

• The proposed FPEEA algorithm shows significant potential for practical application in seismic mitigation.
• FPEEA provides robust performance against both near-fault and far-field earthquake excitations.
• The algorithm enhances structural safety by effectively reducing seismic responses.