Shape memory alloys (SMA) have just recently made their way into structural design, and through studies have proved to be quite effective in increasing a structures strength and performance. Earthquakes are one of the most chaotic natural disasters that occur around the world, significantly impacting infrastructure to the point where cities lose their ability to function as bridges and hospitals are destroyed. The main objective of this paper is to investigate the natural behaviour of steel braced frames reinforced with pseudoelastic (PE) NiTi SMA wires. A free vibrations test was conducted to determine the natural frequency and damping ratio of two different systems. The tests of the steel and PE SMA frames showed that the stiffness of the brace does not affect the natural frequency of the system but rather, the connection of the system to the rigid floor controls the natural behaviour. Findings of this research are expected to add valuable knowledge to the field of seismic retrofitting of structures and widen the potential applications of the SMA in the structural engineering field.

形状记忆合金（SMA）刚进入结构设计，并且经过研究证明，在提高结构强度和性能方面非常有效。地震是世界上最混乱的自然灾害之一，对基础设施造成了严重影响，以致城市失去了桥梁和医院被摧毁的功能。本文的主要目的是研究用伪弹性（PE）NiTi SMA钢丝增强的钢支撑框架的自然性能。进行了自由振动测试，以确定两个不同系统的固有频率和阻尼比。对钢制和PE SMA框架的测试表明，支撑的刚度不影响系统的固有频率，而是 系统与刚性地板的连接可控制自然行为。预期该研究的发现将为结构的地震改造领域增加有价值的知识，并扩大SMA在结构工程领域的潜在应用。