| 摘要: |
| 大坝混凝土的裂缝萌生和失稳扩展分析需要尽可能准确地模拟骨料和砂浆界面的弱不连续,而界面过渡区微米级的厚度模拟使得有限元网格存在网格剖分质量不佳和网格数量庞大的问题。通过在大坝混凝土细观结构的不同材料实体单元间预嵌零厚度界面单元,并进行宏细观子区域界面结点重新匹配,建立了骨料-砂浆-界面单元的宏细观区域分解有限元网格。同时结合隐式梯度损伤模型和内聚力模型,在同一模型中实现骨料、砂浆基质的损伤失效模拟以及骨料-砂浆界面的弱连接到脱开模拟,构建了大坝混凝土非连续变形的宏细观并发多尺度区域分解模型。将模型用于某大坝混凝土的直接拉伸试验模拟,不同随机骨料模型均能捕捉骨料和砂浆界面的弱连接到脱开过程。重现的混凝土试件破坏形态与参考文献结果一致,说明模型是合理的,可为大坝混凝土损伤断裂力学性能研究提供数值试验技术支持。 |
| 关键词: 大坝混凝土 非连续变形 并发多尺度 区域分解法 黏性界面单元 |
| DOI： |
| 分类号:TV313 |
| 基金项目: |
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| Concurrent multi-scale domain decomposition simulation of discontinuos deformation of dam concrete |
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QI Cuige1, QIU Liting2, MA Fuheng2, ZHANG Zhan3, LI Ziyang2
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1.Shimantan Reservoir Administration of Henan Province;2.Nanjing Hydraulic Research Institute;3.Shenzhen shenshui zhaoye engineering consulting CO,LTD
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| Abstract: |
| The analysis of crack initiation and instability propagation of dam concrete needs to simulate the weak discontinuity between aggregate and mortar as accurately as possible. The micron thickness of the interface transition zone makes the finite element mesh have the problems of poor mesh generation quality and large number of meshes. Zero-thickness cohesive interface elements were preset between the solid elements of different material interface. Reassembling subdomain interface configurations after presetting zero-thickness interface elements. Then the aggragate-mortar-interface multi-scale domain decomposition finite element mesh were established. Meanwhile, the gradient-enhanced continuum damage model and the cohesion model were combined to simulate the failure of aggragate and mortar matrix, also the weak link between the aggragate and cement matrix in one model. A macro-meso concurrent multi-scale domain decomposition model for discontinuous deformation of dam concrete was constructed. The model was applied to the direct tensile test simulation of a dam concrete. Both of the random aggregate models could capture the whole process from weak connection to disconnection of the interface between aggregate and mortar. The failure modes reproduced of concrete specimen were in agreement with the result of reference paper, proving that the model is reasonable, which can provide numerical test technical support for the study of damage and fracture mechanical properties of dam concrete. |
| Key words: Dam Concrete Discontinuous Deformation Concurrent Multi-scale domain decomposition Cohesive Interface Elements |
