大坝混凝土楔入劈拉试验的并发多尺度区域分解数值模拟

Numerical simulation of concurrent multiscale domain decomposition for dam concrete wedge splitting test

并发多尺度区域分解法应用于复合材料力学性能的多尺度数值试验研究,可在同一有限元模型中分别实现对损伤子区域的高精度细观网格剖分和对线弹性子区域的高效率宏观网格剖分。采用随机骨料模型模拟大坝混凝土细观结构,再结合并发多尺度区域分解法,建立了大坝混凝土的并发多尺度区域分解有限元模型;然后,将模型应用于全级配随机凹凸型骨料试件的楔入劈拉试验数值模拟。计算结果表明:(1)该模型能够重现大坝混凝土楔入劈拉试件的跨尺度破坏过程,计算所得的P_h-CMOD曲线以及宏观裂缝区扩展模式均与已有文献的物理试验结果相符;(2)模型的最终计算规模仅为全细观尺度有限元模型计算规模的43.18%。数值试验模拟结果与物理试验所得结果的一致性说明模型合理,此外,计算规模的减小使得模型的计算效率得到了显著提升。

Applying concurrent multiscale domain decomposition method to the multiscale numerical simulation on the mechanical properties of composite material can realize high accurate mesoscopic mesh generation of damage sub-regions and efficient macroscopic mesh generation of linear elastic subdomains in one finite element model. A finite element model of concurrent multiscale domain decomposition for dam concrete is established through simulating the mesoscopic structure of dam concrete with random aggregate model and combining concurrent multiscale domain decomposition method, and then the model is applied to the numerical simulation of the wedge splitting test made on the full-gradation specimens of random concave-convex polygon aggregate. The calculation result shows that(1) the cross-scale failure process of the wedge splitting test specimen can be reproduced by this model;from which both the obtained P_h-CMOD curve and the propagation mode of the macroscopic cracking region from the calculation are coincided with those results from the physical experiments described in the relevant existing literatures;(2) the final calculation scale is only 43.18% of that of the full-mesoscopic scale finite element model, while the consistency between both the simulation result of numerical experiment and the result from physical experiment indicates that the model is reasonable. Moreover, the decrease of the calculation scale makes a significant enhance of the calculation efficiency of the model.