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Micro-mechanical fracture dynamics and damage modelling in brittle materials
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences ( IF 5 ) Pub Date : 2021-03-15 , DOI: 10.1098/rsta.2020.0125
Q. Gomez 1 , I. R. Ionescu 1, 2
Affiliation  

This study explores the interplay between wave propagation and damage in brittle materials. The damage models, based on micro-mechanical fracture dynamics, capture any possible unstable growth of micro-cracks, introducing a macroscopic loss of stability. After stating the non-dimensional mathematical problem describing the wave propagation with damage, we introduce a non-dimensional number, called the microscopic evolution index, which links the micro and macro scales and discriminates the microscopic scale behaviour. For large values of microscopic evolution index, corresponding to a microscopic quasi-static process coupled with a macroscopic dynamic one, the macroscopic dynamic system could lose its hyperbolicity or become very stiff and generate shock waves. A semi-analytical solution to the one-dimensional wave propagation problem with damage, which could be very useful in the accuracy evaluation of the numerical schemes, was constructed. Concerning the asymptotic behaviour of the dynamic exact solution on the microscopic evolution index (or on the strain rate), an important strain rate sensitivity was found: the pulse loses its amplitude for decreasing strain rate and, starting with a critical value, the micro-scale model is rate independent. A possible regularization technique to smooth the shock waves at low and moderate strain rates is discussed. Finally, some numerical results analyse the role played by the the friction on the micro-cracks in the damage modelling of blast wave propagation.

This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.



中文翻译:

脆性材料的微机械断裂动力学和损伤建模

这项研究探讨了脆性材料中波传播与损伤之间的相互作用。基于微机械断裂动力学的损伤模型捕获了微裂纹的任何可能的不稳定增长,从而带来了宏观的稳定性损失。在陈述了描述具有损伤的波传播的无量纲数学问题之后,我们引入了一个无量纲数,称为微观演化指数,它将微观和宏观尺度联系起来,并区分微观尺度的行为。对于较大的微观演化指数值,对应于微观准静态过程和宏观动态过程,宏观动态系统可能会失去其双曲性或变得非常僵硬并产生冲击波。具有损伤的一维波传播问题的半解析解,构造了对数值方案的准确性评估非常有用的方法。关于动态精确解在微观演化指数(或应变率)上的渐近行为,发现了一个重要的应变率灵敏度:脉冲因降低应变率而失去振幅,从临界值开始,微观比例模型是与速率无关的。讨论了在低应变率和中等应变率下使冲击波平滑的可能的正则化技术。最后,一些数值结果分析了微裂纹的摩擦在爆炸波传播损伤模型中的作用。关于动态精确解在微观演化指数(或应变率)上的渐近行为,发现了一个重要的应变率灵敏度:脉冲因降低应变率而失去振幅,从临界值开始,微观比例模型是与速率无关的。讨论了在低应变率和中等应变率下使冲击波平滑的可能的正则化技术。最后,一些数值结果分析了微裂纹的摩擦在爆炸波传播损伤模型中的作用。关于动态精确解在微观演化指数(或应变率)上的渐近行为,发现了一个重要的应变率灵敏度:脉冲因降低应变率而失去振幅,从临界值开始,微观比例模型是与速率无关的。讨论了在低应变率和中等应变率下使冲击波平滑的可能的正则化技术。最后,一些数值结果分析了微裂纹的摩擦在爆炸波传播损伤模型中的作用。讨论了在低应变率和中等应变率下使冲击波平滑的可能的正则化技术。最后,一些数值结果分析了微裂纹的摩擦在爆炸波传播损伤模型中的作用。讨论了在低应变率和中等应变率下使冲击波平滑的可能的正则化技术。最后,一些数值结果分析了微裂纹的摩擦在爆炸波传播损伤模型中的作用。

本文是主题主题“固体材料的断裂动力学:从粒子到地球”的一部分。

更新日期:2021-03-15
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