中央带裂缝混凝土循环拉伸断裂试验Felicity效应

Cyclic tensile fracture test of concrete with central crack and Felicity effect

混凝土的声发射特性是其在受载过程中的伴生现象,具有对应力或应变历史的记忆性,可以利用声发射记忆性评价混凝土结构损伤历史。通过中央带裂缝混凝土试件循环拉伸断裂试验,分析了不同声发射参量与循环荷载历程之间的关系,建立了循环拉伸状态下混凝土声发射损伤模式,揭示了初始裂缝宽度对Felicity比的影响规律。结果表明,动态轴向循环荷载作用下,随着初始预制裂缝宽度的增加,混凝土棱柱体试件Felicity比逐渐增大。主要试验成果为采用声发射记忆性来评判混凝土的损伤历史提供了一种新的方法。

As an accompanying phenomenon,the acoustic emission of the concrete has memory of the stress-strain history,which could be used to evaluate the concrete damage history.The cyclic tensile failure experiment of the concrete specimen with central crack was conducted.Relationships between parameters of acoustic emission and cyclic loading process were analyzed.The acoustic emission damage mode of concrete under cyclic tension was established.The influence of initial width of crack on the Felicity rate was revealed.The results indicate that the Felicity rate of the concrete prisms gradually increase with the initial width of the crack under dynamic axial cyclic loading.The key outcomes of this article provide a new process of evaluating the concrete damage history with acoustic emission memory.