堆石颗粒压缩破碎强度的尺寸效应
发布时间：2019-05-19 17:50
【摘要】：目前在颗粒材料的尺寸效应研究中,极少考虑颗粒的复杂形状和内部结构非均匀性。采用随机散粒体不连续变形分析方法(SGDD),引入无厚度界面单元和凝聚力模型模拟颗粒破碎,对5组不同粒径的堆石颗粒进行单颗粒压缩试验的数值模拟,分析了颗粒内界面单元强度对颗粒破碎的影响,并采用Weibull分布模型分析颗粒破碎强度的尺寸效应。通过与室内单颗粒压缩试验对比,试验的数值模拟能真实地再现单颗粒压缩下的破碎过程,不同颗粒的压缩曲线规律相似,达到峰值荷载前,承载力曲线急剧上升,随后颗粒发生致命破碎,承载能力骤降。不同粒径组的单颗粒破碎强度均服从Weibull分布,平均Weibull模数为2.48。不同粒径组的颗粒特征强度存在明显的尺寸效应,特征强度随着颗粒尺寸的增大而减小,与颗粒尺寸呈幂指数关系,但小于Weibull模型的预测值。
[Abstract]:At present, the complex shape and internal structure inhomogeneity of particles are rarely considered in the study of particle size effect. The random bulk discontinuity deformation analysis method (SGDD), introduced the interface element without thickness and the cohesion model to simulate the particle breakage, and the single particle compression test of five groups of rockfill particles with different particle sizes was carried out. The effect of interfacial unit strength on particle breakage was analyzed, and the size effect of particle crushing strength was analyzed by Weibull distribution model. Compared with the laboratory single particle compression test, the numerical simulation of the test can truly reproduce the crushing process of single particle compression, and the compression curve of different particles is similar, and the bearing capacity curve rises sharply before reaching the peak load. Subsequently, the particles were fatally broken and the bearing capacity plummeted. The crushing strength of single particle in different particle size groups obeys Weibull distribution, and the average Weibull modulus is 2.48. The characteristic strength of particles in different particle size groups has obvious size effect, and the characteristic strength decreases with the increase of particle size, which has a power exponential relationship with the particle size, but is smaller than the predicted value of Weibull model.
【作者单位】： 武汉大学水资源与水电工程科学国家重点实验室;武汉大学水工岩石力学教育部重点实验室;
【基金】：中国博士后科学基金面上资助(No.2016T907272) 中央高校基本科研业务费专项资金~~
【分类号】：TV41
，
本文编号：2480932
[Abstract]:At present, the complex shape and internal structure inhomogeneity of particles are rarely considered in the study of particle size effect. The random bulk discontinuity deformation analysis method (SGDD), introduced the interface element without thickness and the cohesion model to simulate the particle breakage, and the single particle compression test of five groups of rockfill particles with different particle sizes was carried out. The effect of interfacial unit strength on particle breakage was analyzed, and the size effect of particle crushing strength was analyzed by Weibull distribution model. Compared with the laboratory single particle compression test, the numerical simulation of the test can truly reproduce the crushing process of single particle compression, and the compression curve of different particles is similar, and the bearing capacity curve rises sharply before reaching the peak load. Subsequently, the particles were fatally broken and the bearing capacity plummeted. The crushing strength of single particle in different particle size groups obeys Weibull distribution, and the average Weibull modulus is 2.48. The characteristic strength of particles in different particle size groups has obvious size effect, and the characteristic strength decreases with the increase of particle size, which has a power exponential relationship with the particle size, but is smaller than the predicted value of Weibull model.
【作者单位】： 武汉大学水资源与水电工程科学国家重点实验室;武汉大学水工岩石力学教育部重点实验室;
【基金】：中国博士后科学基金面上资助(No.2016T907272) 中央高校基本科研业务费专项资金~~
【分类号】：TV41
，
本文编号：2480932
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