本文選題：混凝土壩　切入點(diǎn)：水力劈裂　出處：《工程力學(xué)》2017年04期 　論文類型：期刊論文

【摘要】：基于多邊形比例邊界有限元法和粘聚裂縫模型提出了混凝土壩壩基界面在隨縫寬非線性變化的水壓力驅(qū)動(dòng)下的非線性斷裂數(shù)值模型�；炷梁突鶐r采用多邊形比例邊界單元模擬,界面裂縫的斷裂過(guò)程區(qū)采用粘性界面單元模擬。因?yàn)榻缑媪芽p總是處于復(fù)合斷裂模態(tài),故同時(shí)引入了法向和切向的界面單元,且考慮了裂紋面作用有法向和切向任意荷載時(shí)的應(yīng)力強(qiáng)度因子求解。以裂尖為原點(diǎn),裂尖附近的位移場(chǎng)和應(yīng)力場(chǎng)在徑向上解析求解,在環(huán)向具有有限元精度。因此無(wú)需在裂尖附近加密網(wǎng)格或采用富集技術(shù)即可求得高精度的解。對(duì)于界面斷裂,可模擬出與兩種材料差異性相關(guān)的非1/2奇異性。斷裂過(guò)程區(qū)的水壓力隨縫面寬度變化,采用指數(shù)函數(shù)的形式進(jìn)行表征,通過(guò)參數(shù)調(diào)整可實(shí)現(xiàn)不同分布的水壓力的模擬。水壓力與粘聚力考慮為與裂縫寬度相關(guān)的組合函數(shù),便于非線性迭代的實(shí)現(xiàn)。結(jié)合多邊形網(wǎng)格生成和重剖分技術(shù),可方便地模擬界面裂縫在水力驅(qū)動(dòng)下的擴(kuò)展過(guò)程。算例研究表明了該文模型的有效性,從中也可看出考慮縫內(nèi)水壓及其具體分布形式對(duì)研究壩的穩(wěn)定性具有重要影響。
[Abstract]:Based on polygonal proportional boundary finite element method and cohesive crack model, a nonlinear fracture numerical model for the interface of concrete dam foundation driven by water pressure with nonlinear variation of joint width is presented. The polygon ratio is used for concrete and bedrock. Example boundary element simulation, The viscous interface element is used to simulate the fracture process of the interface crack. Because the interface crack is always in the composite fracture mode, both normal and tangential interface elements are introduced at the same time. The stress intensity factor is solved by taking the crack tip as the origin, and the displacement field and stress field near the crack tip are analytically solved in radial direction. It has finite-element accuracy in the circumferential direction, so it is not necessary to encrypt the mesh near the crack tip or to obtain the high-precision solution by using enrichment technique. The non-#number0# singularity related to the difference between the two materials can be simulated. The water pressure in the fracture process varies with the width of the fracture surface and is characterized by exponential function. Different distribution of water pressure can be simulated by adjusting parameters. Water pressure and cohesive force are considered as combination functions related to crack width, which is convenient for the realization of nonlinear iteration. The numerical example shows the validity of the model, from which it can be seen that considering the water pressure in the joint and its specific distribution form have an important influence on the stability of the dam.
【作者單位】： 大連理工大學(xué)建設(shè)工程學(xué)部;中國(guó)水利水電科學(xué)研究院巖土所;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(51009019,51579033) 中央高校基本科研業(yè)務(wù)費(fèi)專項(xiàng)資金項(xiàng)目(DUT14LK40) 中國(guó)博士后基金特別資助項(xiàng)目(2013T60283) 國(guó)家自然科學(xué)青年基金項(xiàng)目(51109134)
【分類號(hào)】：TV642;TV223
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本文編號(hào)：1593775