Optimization of inelastic multistory structures under seismic vibrations using shape-memory-alloy material.

Area of Science:

• Structural Engineering
• Materials Science
• Optimization Methods

Background:

• Inelastic multistory structures are vulnerable to seismic events.
• Existing seismic protection methods have limitations in adaptability and efficiency.
• Shape-memory-alloys (SMAs) offer unique properties for damping and resilience.

Purpose of the Study:

• To develop a novel optimization methodology for designing Shape-memory-alloy resisting devices (SMARDs).
• To determine the optimal allocation of SMARDs in inelastic multistory structures.
• To enhance the seismic response of structures using SMA technology.

Main Methods:

• A control gains optimization procedure based on a formal optimization problem.
• Utilizing a state-space equation incorporating system inelasticity.
• Employing a five-step iterative algorithm with Hamiltonian gradients for optimality.
• Defining control gains as the number of SMA wires per device and per story.

Main Results:

• The developed algorithm successfully improved the inelastic seismic response of an eight-story frame system.
• Demonstrated the efficiency and reliability of the SMARD design methodology.
• Showcased the effectiveness of SMA materials in seismic retrofitting and performance enhancement.

Conclusions:

• The novel optimization methodology provides a reliable approach for designing and allocating SMARDs.
• The study confirms the significant potential of SMA materials in mitigating seismic risks in structures.
• The algorithm's efficiency in improving inelastic seismic response highlights its practical applicability.