形状记忆合金增强弹性混凝土梁的变形特征

Deformation Characteristic of Concrete Beams Embedded Superelastic Shape Memory Alloy

利用形状记忆合金的超弹性和受限回复产生较大驱动力的特性,研制了一种智能混凝土梁。通过试验研究了形状记忆合金智能混凝土梁的变形规律及其影响因素,揭示了形状记忆合金超弹性梁的自修复机理。试验结果表明:形状记忆合金显著地提高了混凝土梁的变形能力;一旦外力消失,梁在形状记忆合金超弹性效应的驱动下,挠度迅速恢复,裂缝闭合;增加合金的总截面面积可提高合金对混凝土梁的驱动效果,但钢筋塑性变形的存在,则对形状记忆合金梁的变形回复起着阻碍作用。

Taking advantage of the superelasticity effect of shape memory alloy （SMA） and the characteristic of applying large forces on the resisting member in the transformation of SMA when restoring, smart concrete beam was developed by embedding superelastic SMA into the tensile zone of concrete beams during concrete casting. Deformation behavior and influence of factors on the deformation characteristic of SMA smart concrete beam were investigated experimentally. Self-restoring mechanism of SMA smart concrete beam embedded superelastic SMA was analyzed. Experimental results show that SMA significantly increases structural survivability and allows structure to recover from residual deformation by damaged earthquake and typhoon; the crack almost closes completely when unloading after generating a large deflection in the beams. Increasing the consumption of superelastic SMA can significantly improve the capacity of selfrestoration of SMA concrete beams, but the steel main bars play a very negative role in reducing residual deformation.