发表机构
The University of Osaka（大阪大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出含裂纹愈合与疤痕效应的相场模型，模拟干燥-湿润循环下裂纹交角向120°松弛，指数衰减特征时间约2.85个循环，与实验相符。
AI 中文摘要
在重复的干燥-湿润循环下，干燥裂纹的特征交角从接近90°松弛至接近120°。然而，对这种松弛的理论理解尚不充分，尤其是对干燥-湿润循环的建模。本文引入了一个干燥断裂的相场模型，通过在先前研究中提出的模型基础上增加裂纹愈合和过去裂纹留下的疤痕效应来扩展该模型。通过在有限元模拟中重复干燥-湿润循环，我们发现随着循环次数的增加，角度分布在接近120°处出现一个增长的峰值，这与实验一致。交角与120°的标准差以约2.85个循环的特征时间指数松弛。这些结果与实验一致，只是特征时间略小于实验值。裂纹能主导总能量，并且也以与角度松弛几乎相同的特征循环数指数衰减。这种衰减主要由有效裂纹长度的缩短驱动，而非有效断裂韧性的改变。
英文摘要
The characteristic intersection angle of the desiccation crack relaxes from near \ang{90} toward \ang{120} under repeated drying--wetting cycles. However, the theoretical understanding of this relaxation is insufficient, especially the modeling of the drying--wetting cycles. Here we introduce a phase-field model of desiccation fracture, extending the model proposed in previous studies by adding crack healing and a scar effect left by past cracks. By repeating drying--wetting cycles in a finite element simulation, we find that the angle distribution develops a growing peak near \ang{120} as the cycle number increases, consistent with experiments. The standard deviation of the intersection angle from \ang{120} relaxes exponentially with a characteristic time of about 2.85 cycles. These results are consistent with experiments, except that the characteristic time is slightly smaller than the experimental value. Crack energy dominates the total energy and also relaxes exponentially with nearly the same characteristic cycle as the angle relaxation. This decay is driven mainly by a shortening of the effective crack length rather than a change in effective fracture toughness.
Comments38 pages, 10 figures
