报告题目：Microstructural Randomness and Mechanical Properties of Materials

报告时间：2021-12-09  15:00-16:30

报告人：谷晔俊 博士 Institute of High Performance Computing (IHPC)

腾讯会议ID：328-259-669

Abstract：The mechanical properties of metallic materials are strongly dependent on their microstructural features (e.g. morphology and distribution of dislocations, grains, and other defects), where the microstructures exhibit randomness associated with the processing conditions (e.g. temperature, pressure, loading strain rate). Thus it necessitates a better understanding of the effects of the microstructural randomness on the mechanical properties. I will present two problems with this topic. One is the probabilistic persistent slip band (PSB) nucleation model, to predict the number of cycles required for PSB formation in single crystals as a function of the crystal size. This nucleation model captures the size effect on the PSB nucleation cycle number that a smaller sample requires a higher number of cycles for PSB formation. This explains the lack of observations of PSBs in many of the small-scale tests in literature that did not reach a large enough number of cycles. The other problem is the probabilistic description of material strength, as a function of microstructure features. The conventional Hall-Petch relationship is revisited and reformulated in a probabilistic perspective, to account for the uncertainty of material strength prediction associated with the microstructural randomness.