Predicting the properties of complex materials from molecular simulations

计算机仿真已成为科学研究中实验与理论的重要伙伴。它有望以高精度预测凝聚态物质的复杂行为，探索实验无法获得的参数，并指导新功能材料的定向设计。本研究采用分子水平模拟作为计算显微镜，以更好地了解非晶固体在应力下的流动。重要的例子包括聚合物和金属玻璃，它们在许多日常应用中都很常见，但我们对这些材料的塑性基本机制的理解远不如我们对金属等结晶固体的了解先进。无序固体中的变形物理学为检验和探索非平衡统计物理学中的新概念提供了一个具有挑战性的机会。为了提高工程实践的可靠性，我们开发了一种多尺度方法，其中原子水平上塑性活动的时空组织反映在本构模型中，该模型以高保真度预测大范围参数的力学行为。

Computer simulation has become an invaluable partner of experiment and theory in scientific research. It holds the promise of predicting the complex behaviour of condensed matter with high accuracy, exploring parameters inaccessible to experiments, and guiding the targeted design of new functional materials. This research employs molecular level simulations as computational microscope to better understand how amorphous solids flow under stress. Important examples include polymer and metallic glasses that are familiar from many everyday applications, but our understanding of the elementary mechanisms of plasticity in these materials is far less advanced than our knowledge of crystalline solids such as metals. The physics of deformation in disordered solids provides a challenging opportunity to test and explore new concepts in nonequilibrium statistical physics. In order to improve the reliability of engineering practices, we develop a multiscale approach, where the spatio- temporal organization of plastic activity at the atomic level is reflected in constitutive models that predict the mechanical behaviour for a wide range of parameters with high fidelity.