基于形状记忆合金的自复位摩擦耗能支撑滞回性能

Hysteresis performance of self-centering friction damping braces based on shape memory alloy

针对基于形状记忆合金(SMA)的自复位摩擦耗能支撑,提出了简化分析模型,研究了其在往复荷载作用下的滞回性能.首先通过理论推导,得出了往复荷载作用下自复位摩擦耗能支撑的力-位移曲线,提出了简化的滞回模型,然后通过参数分析研究了各参数对其滞回性能的影响.结果表明:自复位摩擦耗能支撑在卸载后存在一定的残余位移,其大小仅与阻尼器元件摩擦力及SMA元件奥氏体弹性刚度有关;自复位摩擦耗能支撑的滞回性能可采用修正的FS(Flag-shaped)模型来描述;SMA元件屈服力及耗能参数对自复位摩擦耗能支撑的滞回性能影响较大,奥氏体弹性刚度及屈服后刚度系数影响较小;增加阻尼器元件的摩擦力,可显著增强自复位摩擦耗能支撑的耗能能力,但会产生残余位移.

A simplified analysis model is proposed for the self-centering friction damping brace （SFDB） based on shape memory alloy （SMA） ; and then its hysteresis performance under reversal loading is stud- ied. By way of theoretical derivation, the force vs. displacement curve of the SFDB subjected to reversal loading is obtained and the simplified hysteresis model of the SFDB is proposed. Based on the above work, the influences of parameters on the hysteresis performance of the SFDB are analyzed parametrically. It is indicated that certain residual displacement occurs upon unloading of the SFDB, the magnitude of which are only related to the friction of the damper component and the austenite elastic stiffness of the SMA com- ponent; and the hysteresis performance of the SFDB can be described by the modified Flag shaped（FS） model. The yield force and energy dissipation parameter of the SMA component have a great impact on the hysteresis performance of the SFDB; while the effects of the austenite elastic stiffness and post-yield stiff- ness ratio are relatively small. The energy dissipation capacity of the SFDB can be significantly enhanced by increasing the friction of the damper component whereas it yields some residual displacement.