SMA丝增强SHCC拉伸时的变形和裂纹自回复性能研究  

Self-recovery of Deformation and Crack of SMA Wire Reinforced SHCC under Tension

作　　者：王钢[1] 孙明清[1] 刘记立 王应军[1] WANG Gang;SUN Mingqing;LIU Jili;WANG Yingjun(Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology,Wuhan 430070, China)

机构地区：[1]武汉理工大学新材料力学理论与应用湖北省重点实验室,武汉430070

出　　处：《硅酸盐通报》2020年第6期1728-1733,1741,共7页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51974217);武汉理工大学研究生优秀学位论文培育项目(2017-YS-078);中央高校基本科研业务费专项资金(2019IB008)。

摘　　要：将单根形状记忆合金(SMA)丝埋入应变硬化水泥基复合材料(SHCC)中,采用循环拉伸试验研究SMA丝的预拉伸应变大小(分别为0%、2%、4%和5.5%)对SHCC拉伸应力-应变关系、残余应变回复率、裂纹平均宽度、裂纹回复性等的影响。结果表明,SMA丝的埋入提高了SHCC的初裂强度、极限强度和极限应变。SMA丝的预拉伸应变较大时,SMA增强SHCC的延性和强度较高。采用加热方法驱动SMA丝可使SHCC的残余应变减小,含预拉伸SMA丝的SHCC试样的变形回复率达到60%~90%,而含未预拉伸SMA丝的SHCC试样的变形回复率仅为20%~42%。SMA丝预拉伸应变增加时,SMA丝驱动后SHCC中裂纹的平均宽度变小。当驱动预拉伸应变为5.5%的SMA丝时,SMA增强SHCC的裂纹平均宽度约为10μm。Single shape memory alloy(SMA)wire was buried into strain hardening cementitious composites(SHCC),then the cyclic tensile tests were carried out to study the influences of preload strain of SMA wire such as 0%,2%,4%and 5.5%on the tensile stress-strain relationship of SHCC,the recovery rate of residual strain,the average width of crack,crack self-recovery,etc.Results show that the addition of SMA wire improves the initial crack strength,ultimate strength and ultimate strain of SHCC.As the preload strain of SMA wire increases,the tensile ductility and strength of SMA wire reinforced SHCC increase.The residual strain of SHCC reduces resulting from heating SMA wires.The deformation recovery rate of SHCC containing the pre-tension SMA wire SHCC specimens reaches about 60%-90%,while it is only 20%-42%for normal SMA wire.As the preload strain of SMA wire increases,the average crack width of SHCC decreases.When the preload strain of SMA wire is 5.5%,the average crack width of SHCC is about 10μm.

关 键 词：形状记忆 应变硬化 变形回复率 裂纹平均宽度 自愈合 

分 类 号：TG139.6[一般工业技术—材料科学与工程] TV431.3[金属学及工艺—合金]