Collaborative Research: Damage in Soft Solids: Elasticity vs Fracture

该提案的研究目标是直接从弹性体的弹性行为、断裂行为以及损伤可能发生的缺陷的性质方面，对弹性体中损伤的发生和传播进行基本的定量理解。第二个目标是利用这一理解来探讨和确定损害可能导致失败的制度，以及另一方面，损害可能被用作有益机制的制度。这将通过实验/理论相结合的方法来实现。在实验方面，将使用最先进的光学设备，在广泛的系统变化条件下现场监测损害的空间和时间演变。从理论上讲，最近的创新微观力学技术的分析有限变形固体含有一般类的缺陷将被用来作为基础，以建立一个断裂力学框架的能力，以确定损伤的启动和传播在非线性弹性固体在一般载荷条件下。（弹性体、凝胶和生物组织等能够承受大的可逆变形的材料）是损伤的引发和传播的原因，人们对此知之甚少。 该项目将提供前所未有的现场实验数据和精确的定量洞察力的过程中的损伤引发和损伤扩展的弹性体。它也将提供，第一次，易处理的分析技术来研究不可逆的增长，通过断裂的缺陷与现实的几何形状在非线性固体受到任意有限变形。 在应用层面上，这项工作将提出一个定量的基础上的几何形状，材料性能和加载条件，以确定何时损坏导致故障，以及何时（以及如何）可以使用的优势。 研究成果将被纳入研究生课程在UIUC和UT奥斯汀，研究人员将继续在指导和推广活动的参与。

The research objective of this proposal is to develop fundamental quantitative understanding of the initiation and propagation of damage in elastomers directly in terms of their elastic behavior, their fracture behavior, and the properties of the defects at which damage can initiate. A second objective is to make use of this understanding to explore and identify regimes where damage may lead to failure and where, on the other hand, it may be utilized as a beneficial mechanism. This will be accomplished by means of a combined experimental/theoretical approach. Experimentally, use will be made of state-of-the-art optical equipment to monitor in-situ the spatial and temporal evolution of damage under a wide range of systematically varied conditions. Theoretically, recent innovative micromechanics techniques for the analysis of finitely-deformable solids containing general classes of defects will be utilized as the basis to construct a fracture mechanics framework with the capability to determine damage initiation and propagation in nonlinear elastic solids under general loading conditions.A key aspect of the mechanics of soft solids (materials such as elastomers, gels, and biological tissues that are able to undergo large reversible deformations) that is poorly understood, is that of the initiation and propagation of damage. This project will provide unprecedented in-situ experimental data and precise quantitative insight into the processes of damage initiation and damage propagation in elastomers. It will also make available, for the first time, tractable analytical techniques to study the irreversible growth via fracture of defects with realistic geometries in nonlinear solids subjected to arbitrary finite deformations. At the applications level, this work will put forward a quantitative basis in terms of geometry, material properties, and conditions of loading to determine when damage leads to failure and when (and how) it may be used to an advantage. Research results will be integrated into the graduate curricula at UIUC and UT Austin, and the researchers will continue their participation in mentoring and outreach activities.