掺碳纳米管固废混凝土的声发射损伤本构模型分析

Research on Acoustic Emission Constitutive Model of Solid Waste Concrete Incorporated with Carbon Nanotubes

摘要:

为明确掺加碳纳米管固废混凝土声发射参数与损伤演化关系，对不同再生骨料取代率和碳纳米管（CNT）掺量的固废混凝土进行单轴压缩声发射试验，根据声发射参数构建了损伤本构模型，通过应变-损伤变量进行固废混凝土内部损伤分析。结果表明：当CNT掺量为0.10%时，固废混凝土抗压强度最大，能量、累计振铃计数及b值变化相对密实；碳纳米管固废混凝土失稳破坏伴随能量、累计振铃计数和b值的突变。所建立的损伤本构模型有效拟合了试件的应力-应变全曲线，损伤变量随应变的增加呈现S型增长趋势，该模型可准确描述碳纳米管固废混凝土的损伤演化过程。

Abstract:

To investigate the relationship between acoustic emission parameters and damage evolution in solid waste concrete， uniaxial compression tests were conducted with different substitution ratios of recycled aggregates and different dosages of carbon nanotubes（CNT）. The entire testing process was monitored for damage using acoustic emission technology， and a damage constitutive model based on the stress-strain curve was established. Internal damage analysis of the solid waste concrete was performed using strain-damage variables. The results indicate that when the CNT incorporation rate is 0.10%， the compressive strength of the solid waste concrete reaches the highest value. Meanwhile the changes in energy， cumulative ring count， and b-value are relatively dense. Through the analysis of acoustic emission parameters， it is found that the unstable failure of solid waste concrete occurrs with the abrupt change stages of energy and cumulative ring count. The established damage constitutive model effectively fits the entire stress-strain curve of the specimen. In this model， the damage variable exhibits an S-shaped growth trend with the increase of strain， which can accurately describe the damage evolution process of solid waste concrete within a specific time.