基于Arduino的SMA丝材智能修复损伤钢筋混凝土梁试验研究

Experimental Study on Arduino-Based Intelligent Damage Repair in Reinforced Concrete Beams with SMA Wires

为修复钢筋混凝土梁在使用阶段中由于材料老化、裂缝开展等原因造成的损伤,提出一种基于Arduino智能平台和形状记忆合金(Shape Memory Alloy,SMA,具有形状记忆效应和超弹性特性)的智能修复控制系统,根据挠度及裂缝控制原理,设计智能修复控制装置。该装置由输入模块、处理模块和输出模块组成,当检测到钢筋应变超过限值时,输出模块升高SMA丝材温度对梁体进行修复。为验证该智能修复装置的修复性能,设计对比梁A(无修复装置)与试验梁B(加装智能修复控制装置),在加载过程中对试验梁B进行3次修复,对2根梁的跨中挠度、钢筋应变及裂缝宽度等进行对比分析。结果表明:破坏时试验梁B的跨中挠度、裂缝宽度均小于对比梁A,并且在3次修复中试验梁B的跨中挠度、裂缝宽度和钢筋应变最大回复率分别为31.0%、47.0%和71.5%。说明该智能修复控制装置可以监测试验梁受损情况并激发SMA材料对试验梁实施修复,实现钢筋混凝土梁的智能修复。

This study presents an intelligent damage repair control system that is developed based on Arduino(an open-source electronics platform)and shape memory alloy(SMA)wires,which is specialized in repairing the damages of reinforced concrete(RC)beams caused by material aging and cracking.Intelligent repair control devices,consisting of the input,process and output modules,are designed following the deflection and crack control principles of the intelligent control system.When oversized reinforcement strains(exceeding the limits)are detected,the output modules will raise the temperature of SMA wires to repair the beam body.A control beam(beam A without repair device)and a test beam(beam B with smart repair device)were prepared to verify the damage repair performance of the intelligent repair control device.During the test,beam B were repaired for three times,and beam A and beam B were compared from perspectives of midspan deflection,reinforcement strain and crack widths.It is shown that the midspan deflection and crack widths of beam B are less than those of beam A,and during the three times of repairs,the maximum recoverability of the midspan deflection,crack widths and reinforcement strain are 31.0%,47.0%and 71.5%,respectively,indicating that the intelligent repair control device is capable of monitoring the damage conditions of the test beam and activate the SMA material to repair the damages to achieve the intelligent repair of the RC beam.