低温钢纤维混凝土破坏过程的数值模拟
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摘要
通过实验测试了钢纤维混凝土在低温下的力学性能,发现其抗拉和抗压强度随温度降低逐渐升高。运用RMT-150B型岩石力学试验系统对钢纤维混凝土圆柱型试样进行了单轴压缩分析,发现低温下钢纤维混凝土应力应变曲线可分为弹性阶段,裂缝稳态扩展阶段,裂缝失稳扩展阶段和破坏阶段。将混凝土看成是细观上的各向异性非均匀准脆性材料,运用RF-PA2D数值分析软件对钢纤维混凝土单轴压缩全过程进行了数值模拟,模拟得到的承载力随温度降低逐渐增大,均质度好的试件声发射较为集中,声发射能量随温度降低不断提高,体现了低温下钢纤维混凝土的脆性特征。
The mechanical properties of SFRC was tested by experiments under low temperature. It is discovered that the tensile and compressive strengths of SFRC was gradually increased as the temperature reduced. The cylinder sample of SFRC is analyzed in uniaxial compression conditions by RMT-150B rock mechanics experiment system under low temperature. It is discovered that the stress-strain curve of SFRC can be divided into elastic stage ,crack stably expanding stage ,crack unstably expanding stage , failure stage, Concrete is regarded as mesoscopic anisotorpic nonuniform quasi-brittle material and the numerical simulation is carried on the uniaxial compression process of SFRC by RFPA~(2D). It is obtained that the bearing capacity is gradually increased as temperature reduced, the acoustic emission of good heterogeneity samples is relatively centralized, and the energy of acoustic emission is increased as the temperature reduced, which showed the brittleness character of SFRC in low temperature.
The mechanical properties of SFRC was tested by experiments under low temperature. It is discovered that the tensile and compressive strengths of SFRC was gradually increased as the temperature reduced. The cylinder sample of SFRC is analyzed in uniaxial compression conditions by RMT-150B rock mechanics experiment system under low temperature. It is discovered that the stress-strain curve of SFRC can be divided into elastic stage ,crack stably expanding stage ,crack unstably expanding stage , failure stage, Concrete is regarded as mesoscopic anisotorpic nonuniform quasi-brittle material and the numerical simulation is carried on the uniaxial compression process of SFRC by RFPA~(2D). It is obtained that the bearing capacity is gradually increased as temperature reduced, the acoustic emission of good heterogeneity samples is relatively centralized, and the energy of acoustic emission is increased as the temperature reduced, which showed the brittleness character of SFRC in low temperature.
引文
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[2] 唐春安.岩石破裂过程声发射的数值模拟研究[J].岩石力学与工程学报,1997,16(2):368-369.
[3] 金芷生,庞云.钢纤维混凝土疲劳性能初探[J].武汉工业大学学报,1991,13(1):48-49.
[4] 张福保,张庆宗.钢纤维增强混凝土弯曲疲劳强度实验研究[J].武汉工业大学学报,1991,13(1):93-94.
[5] 朱万成.混凝土三点弯曲试件破坏过程的数值模拟[J].力学与实践,1999,21(5):55-56.
[6] 刘光延,王宗敏.用随机骨料模型数值模拟混凝土材料的断裂[J].清华大学学报,1996,36(1):84-85.
[7] 王宗敏.混凝土应变软化与局部化的数值模拟[J].应用基础与工程科学学报,2000,8(2):188-188.
[8] 朱万成.混凝土拉伸断裂过程及尺寸效应的数值模拟[J].岩土力学,2002,23(2):149-149.
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