新形式超弹性形状记忆合金线材力学性能试验研究

Experimental investigation on mechanical properties of new form superelastic shape memory alloy wires

超弹性是形状记忆合金(SMA)的重要特性之一.鉴于钢绞线在力学性能上的优势,提出一种新形式的SMA线材——SMA绞线,其目的在于将其埋设到土木工程领域的混凝土构件中.通过试验,主要研究了应变幅值和加卸载循环次数对普通圆截面SMA丝材和SMA绞线的应力诱发马氏体相变应力、残余应变、最大相变应变和耗能能力的影响.研究结果表明,SMA绞线比SMA丝具有更好的力学性能.建议在工程应用中将SMA的线材形式作为一项影响其超弹性力学性能的因素.

Superelasticity is one of the most important properties of shape memory alloy （SMA）. Considering the advantages of steel strands in mechanical properties, a new form of SMA wires -- SMA strands, is proposed, which can be applied to concrete members. The superelastic mechanical properties, such as stress-induced martensite phase transformation stress, residual strain, maximum phase transition strain and damping properties, of the SMAs in both the ordinary SMA wires and the strands are compared with respect to strain amplitude and cyclic number. By analyzing the test results, a conclusion can be drawn that the mechanical properties of the SMA strands are better than those of the SMA wires. The form of SMA is suggested as an influencing factor of the superelastic mechanical properties.