Fovargue Daniel, Mitran Sorin, Sankin Georgy, Zhang Ying, Zhong Pei
Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina, 27599-3250.
Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708.
Int J Fract. 2018 May;211(1-2):203-216. doi: 10.1007/s10704-018-0283-x. Epub 2018 Apr 19.
A damage model suggested by the Tuler-Butcher concept of dynamic accumulation of microscopic defects is obtained from experimental data on microcrack formation in synthetic kidney stones. Experimental data on appearance of microcracks is extracted from micro-computed tomography images of BegoStone simulants obtained after subjecting the stone to successive pulses produced by an electromagnetic shock-wave lithotripter source. Image processing of the data is used to infer statistical distributions of crack length and width in representative transversal cross-sections of a cylindrical stone. A high-resolution finite volume computational model, capable of accurately modeling internal reflections due to local changes in material properties produced by material damage is used to simulate the accumulation of damage due to successive shocks. Comparison of statistical distributions of microcrack formation in computation and experiment allows calibration of the damage model. The model is subsequently used to compute fracture of a different aspect-ratio cylindrical stone predicting concurrent formation of two main fracture areas as observed experimentally.
由微观缺陷动态累积的图勒-布彻概念提出的损伤模型，是从合成肾结石中微裂纹形成的实验数据获得的。微裂纹出现的实验数据是从贝戈石模拟物的微观计算机断层扫描图像中提取的，这些模拟物是在将结石置于电磁冲击波碎石机源产生的连续脉冲作用后获得的。数据的图像处理用于推断圆柱形结石代表性横向横截面中裂纹长度和宽度的统计分布。一个高分辨率有限体积计算模型能够精确模拟由于材料损伤产生的材料特性局部变化引起的内部反射，用于模拟连续冲击导致的损伤累积。计算和实验中微裂纹形成统计分布的比较允许对损伤模型进行校准。该模型随后用于计算不同纵横比圆柱形结石的断裂，预测如实验观察到的两个主要断裂区域的同时形成。
