【摘要】：目前在顆粒材料的尺寸效應研究中,極少考慮顆粒的復雜形狀和內(nèi)部結構非均勻性。采用隨機散粒體不連續(xù)變形分析方法(SGDD),引入無厚度界面單元和凝聚力模型模擬顆粒破碎,對5組不同粒徑的堆石顆粒進行單顆粒壓縮試驗的數(shù)值模擬,分析了顆粒內(nèi)界面單元強度對顆粒破碎的影響,并采用Weibull分布模型分析顆粒破碎強度的尺寸效應。通過與室內(nèi)單顆粒壓縮試驗對比,試驗的數(shù)值模擬能真實地再現(xiàn)單顆粒壓縮下的破碎過程,不同顆粒的壓縮曲線規(guī)律相似,達到峰值荷載前,承載力曲線急劇上升,隨后顆粒發(fā)生致命破碎,承載能力驟降。不同粒徑組的單顆粒破碎強度均服從Weibull分布,平均Weibull模數(shù)為2.48。不同粒徑組的顆粒特征強度存在明顯的尺寸效應,特征強度隨著顆粒尺寸的增大而減小,與顆粒尺寸呈冪指數(shù)關系,但小于Weibull模型的預測值。
[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.
【作者單位】： 武漢大學水資源與水電工程科學國家重點實驗室;武漢大學水工巖石力學教育部重點實驗室;
【基金】：中國博士后科學基金面上資助(No.2016T907272) 中央高�；究蒲袠I(yè)務費專項資金~~
【分類號】：TV41
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本文編號：2480932