【交通科学与工程学院】短期课程与学术报告

课程信息

课程主题：Constitutive modelling of chemo-mechanical phenomena in solids

主讲人：Professor Laurence Brassart, University of Oxford (牛津大学)

时间：3月13日（星期三）16:00-17:00

地点：北京航空航天大学 沙河校区主楼B706教室

主持人：谭力豪 助理教授，北京航空航天大学 交通科学与工程学院

时间：3月14日（星期四）16:00-17:00

地点：北京航空航天大学 学院路校区新主楼D218教室

主持人：陈建安 副教授，北京航空航天大学 生物与医学工程学院

报告信息

报告题目：Coupled degradation and mechanics in polymers and gels

报告人：Professor Laurence Brassart, University of Oxford (牛津大学)

时间：3月15日（星期五）17:00-18:00

地点：北京航空航天大学 学院路校区新主楼C201教室

主持人：谭力豪 助理教授，北京航空航天大学 交通科学与工程学院

陈玉丽 教授，北京航空航天大学 航空科学与工程学院

陈建安 副教授，北京航空航天大学 生物与医学工程学院

报告摘要：

Hydrolysis is the main degradation pathway in many biodegradable polymers used in biomedical applications, such as orthopaedic fixtures, cardiovascular stents, and tissue engineering scaffolds. Hydrolytic degradation involves the breaking of the polymer chains, leading to a reduction in molecular weight and mass loss by diffusion of the short chains. These microstructural changes in turn impact the mechanical properties, including modulus, strength, elongation, and toughness. Accurate predictions of the microstructure evolution over long degradation times, as well as their impact on mechanical properties, is a prerequisite to accurate chemo-mechanical simulations of biodegradable devices.  In this talk I will describe our recent efforts to address this question by proposing new constitutive models within a continuum thermodynamic framework coupling large deformation, mass transport and hydrolysis reaction. For hydrogels, we propose a physics-based model to describe the loss of elasticity and mass loss in crosslinked networks. Our model can successfully reproduce degradation-induced swelling reported in experiments for several model hydrogels.  For degradable polyesters, such as PLA, we formulate a new model for chain scission which accounts for the degradation mechanism (random scission, end-chain scission, or a combination of both) as well as autocatalysis. The chain scission model can be coupled to elasto-viscoplasticity to simulate concurrent changes in mechanical properties. Numerical examples and comparisons to experimental data will be presented.

报告人简介

Professor Laurence Brassart, University of Oxford (牛津大学), laurence.brassart@eng.ox.ac.uk

Laurence Brassart is an Associate Professor in the Solid Mechanics & Materials Group of the Department of Engineering Science at the University of Oxford. She received her diploma in Mechanical Engineering from the University of Louvain in Belgium in 2007, followed by a PhD in Engineering Sciences from the same university in 2011. She then successively held postdoctoral positions at Harvard University (BAEF Fellowship) and the University of Louvain (FNRS Fellowship). From 2015 to 2019, she was a Senior Lecturer in the Department of Materials Science and Engineering at Monash University in Australia. Laurence’s research focuses on the micromechanical and constitutive modelling of engineering materials, including Polymers, Composites, Soft Materials and Energy Materials. She is particularly interested in multiphysics and multiscale aspects. In 2022, Laurence was awarded a UKRI Future Leaders Fellowship focused on the chemo-mechanics of biodegradable polymers.