本文選題：離散元 + 膠結(jié)模型�。� 參考：《巖土工程學(xué)報》2017年05期

【摘要】：在深海能源土、巖石風(fēng)化等問題離散元模擬中,顆粒間膠結(jié)物的增減將對材料宏觀力學(xué)特性有顯著影響,因此需要建立考慮膠結(jié)厚度和寬度的膠結(jié)模型。針對離散元理論中粒間真實形狀膠結(jié)物在粒間力作用下的剛度和強度確定問題,基于原始的Dvorkin理論,給出高精度的膠結(jié)力學(xué)響應(yīng)理論解。求解中將位移函數(shù)對稱化,提出一種修正位移試函數(shù)的方法,提高了二維顆粒微觀膠結(jié)模型應(yīng)力場的對稱性和精度,經(jīng)驗證解答在定性和定量上符合有限元模擬結(jié)果。根據(jù)所得解答對膠結(jié)物幾何參數(shù)進行了分析,討論了膠結(jié)寬度和厚度對膠結(jié)剛度的影響,并給出了針對一般常見材料的剛度擬合公式。采用雙剪統(tǒng)一強度理論分析了脆性和塑性膠結(jié)材料的初始破壞區(qū)位置,給出拉/壓剪復(fù)合受力狀態(tài)的強度包線。本文解答可方便快捷地獲得膠結(jié)模型的大量力學(xué)響應(yīng)信息,可作為試驗數(shù)據(jù)的驗證和補充,協(xié)助建立膠結(jié)物在復(fù)雜荷載作用下的破壞判據(jù),進而建立完整的離散元膠結(jié)模型。
[Abstract]:In the discrete element simulation of deep-sea energy soil, rock weathering and other problems, the increase and decrease of intergranular binder will have a significant effect on the macroscopic mechanical properties of materials, so it is necessary to establish a cementing model considering the thickness and width of the cementation. In order to determine the stiffness and strength of the intergranular real shape cement under the action of intergranular force in discrete element theory, based on the original Dvorkin theory, a high-precision theoretical solution to the mechanical response of the cementation is presented. A method of modifying the displacement test function is proposed to improve the symmetry and accuracy of the stress field in the two-dimensional micro-cementing model of particles. It is verified that the solution accords with the finite element simulation results qualitatively and quantitatively. Based on the solutions, the geometric parameters of the cement are analyzed, the effects of the width and thickness of the bond on the stiffness of the cement are discussed, and the stiffness fitting formulas for common materials are given. The location of the initial failure zone of brittle and plastic cemented materials is analyzed by using the double shear unified strength theory and the strength envelope of the tension / compression shear composite state is given. In this paper, a large amount of mechanical response information of the cementing model can be obtained conveniently and quickly, which can be used as the verification and supplement of the experimental data, and help to establish the failure criterion of the cement under complex loads, and then to establish the complete discrete element cementing model.
【作者單位】： 同濟大學(xué)土木工程防災(zāi)國家重點實驗室;同濟大學(xué)航空航天與力學(xué)學(xué)院;同濟大學(xué)土木工程學(xué)院地下建筑與工程系;
【基金】：國家自然科學(xué)基金項目(11572228,51639008) 中央高校基本科研業(yè)務(wù)費專項資金—學(xué)科交叉類 國家重點基礎(chǔ)研究發(fā)展計劃(“973”計劃)項目(2014CB046901) 同濟大學(xué)土木工程防災(zāi)國家重點實驗室自主課題(SLDRCE14-B-11)
【分類號】：TU521

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