模型尺寸和骨料级配对混凝土细观非均质影响

发布时间：2018-01-31 16:58

  本文关键词： 混凝土 细观非均质 单元弹性模量 网格单元尺寸 模型尺寸 骨料级配　出处：《应用基础与工程科学学报》2017年02期 　论文类型：期刊论文

【摘要】：针对现有细观力学模型无法反映模型尺寸和骨料级配对混凝土材料细观非均质影响的局限性,假定混凝土由骨料颗粒、砂浆基质及界面过渡区组成,基于Voigt并联模型对细观单元材料力学性能进行等效,建立反映混凝土细观非均质的等效模型.以Weibull分布为假设分布,探讨四种骨料级配边长150-750mm细观等效模型的网格单元尺寸,以单元弹性模量的非均质分布表征材料的细观非均质性,探讨混凝土材料细观非均质性与模型尺寸和骨料级配的相关关系,研究材料细观非均质对混凝土强度及破坏模式的影响机理.研究结果表明:相同骨料级配下,随着模型尺寸的增加,网格单元尺寸增大,混凝土材料非均质性减弱;相同模型尺寸下,随着骨料级配的增大,网格单元尺寸略有增加,混凝土材料的细观非均质性增强;材料细观非均质性增强时,混凝土强度略有降低,损伤破坏区域分布广泛.
[Abstract]:In view of the existing micromechanics model cannot reflect the size of model and the aggregate gradation limitation of concrete meso heterogeneity effect, by the assumption that the concrete aggregate particles, consisting of mortar matrix and interfacial transition zone, Voigt parallel model of meso element equivalent in mechanical properties of materials based on the established equivalent model of concrete meso heterogeneity. Based on Weibull distribution of grid cell size distribution hypothesis, four kinds of aggregate gradation side 150-750mm meso equivalent model, the meso heterogeneity of heterogeneous distribution of material elastic modulus of elements, to discuss the relationship between concrete meso heterogeneity and model size and aggregate gradation, microscopic mechanism of heterogeneous materials research the influence of concrete strength and failure mode. The results show that: the same aggregate gradation, along with the increase of model size, mesh size, The heterogeneity of weakened concrete materials; the same model size, with the increase of aggregate gradation, grid cell size increases slightly, the concrete material meso heterogeneity enhancement; meso heterogeneity increased, concrete strength decreased slightly, the damage zones are distributed widely.

【作者单位】： 防灾科技学院;北京工业大学城市与工程安全减灾教育部重点实验室;
【基金】：中国地震局教师科研基金项目(20120104) 国家自然科学基金项目(51408127)
【分类号】：TU528
【正文快照】： 混凝土是重要的建筑材料,广泛应用于房屋建筑、高坝、桥梁、海洋平台、核电站、地基基础等工业与民用建筑领域,由于结构跨度和高度的增加,混凝土构件尺寸越来越大、受力越来越复杂,对承载能力要求越来越高,迫切需要开展混凝土材料破坏机理、尺寸效应等宏观力学特性的深入研究.，

本文编号：1479547