论文部分内容阅读
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.
In view of the limitation that the existing meso-mechanics model can not reflect the influence of model size and aggregate gradation on the mesoscopic heterogeneity of concrete, it is assumed that the concrete consists of aggregate particles, mortar matrix and interface transition zone. Based on Voigt parallel model, The equivalent mechanical properties of the element materials were established to establish an equivalent model reflecting the mesoscopic heterogeneity of concrete.With the Weibull distribution as a hypothetical distribution, the mesh unit size , The inhomogeneous distribution of elastic modulus of the unit is used to characterize the mesoscopic heterogeneity of the material. The correlation between the mesoscopic heterogeneity of the concrete material and the size of the aggregate and the aggregate gradation is also discussed. The mesoscopic heterogeneity of the material The results show that under the same aggregate gradation, with the increase of the model size, the size of the grid cell increases and the heterogeneity of the concrete material decreases. Under the same model size, As the material gradation increases, the unit cell size increases slightly, and the mesoscopic heterogeneity of concrete material increases. When the mesoscopic heterogeneity of material increases, the strength of concrete decreases slightly and the damage damage area is widely distributed .