Department of Mechanical and Aerospace Engineering Seminar: Experiments and Machine Learning-Informed Modeling for the Structuro-Elasto-Plastic Deformation of Disordered Granular Solids

Hongyi Xiao, Ph.D., Postdoctoral Fellow

Department of Physics and Astronomy, University of Pennsylvania

Experiments and Machine Learning-Informed Modeling for the Structuro-Elasto-Plastic Deformation of Disordered Granular Solids

Abstract: Understanding the interplay between the local disordered structure and the dynamics is important for modeling the deformation of soft amorphous materials. In this talk, I will discuss how granular materials can be used as a highly tunable model material to address this challenge. A granular raft was experimentally designed which consists of particles trapped at an air-oil interface that induces capillary attractions between them. Under tensile deformation, particle rearrangement events gradually localize into an inclined shear band, upon which failure occurs, and the ductility of the raft can be tuned by controlling the capillary interactions via the particle size. For the local structure-dynamic interactions, a machine learning method was used to develop a scalar field, softness, which is a structural descriptor that predicts the propensity of a particle to rearrange. Microscopic interactions between elasticity, local rearrangements and their nearby softness field were extracted and used to inform a structro-elasto-plastic model that can capture shear band formation and the brittle-to-ductile transition.

Dr. Hongyi Xiao is a postdoctoral fellow in the Department of Physics and Astronomy at the University of Pennsylvania. He obtained his PhD in Mechanical Engineering from Northwestern University in 2018 and his BE in Thermal Engineering from Tsinghua University in 2014. He received the Martin Outstanding Doctoral Fellowship in 2017 and the Belytschko Outstanding Research Award in 2018 from Northwestern University for his PhD work on understanding and modeling of segregation in flowing granular materials. He is currently utilizing granular materials to study the microscopic structure-dynamic relations that determine the mechanical behaviors for soft disordered solids, while exploring possible approaches to structurally design advanced disordered materials.

Please contact Hind BenGagr for Zoom information.