Connecting Bond-breaking and Healing Kinetics to the Deformation and Fracture of Tough Hydrogels

将断键和愈合动力学与坚韧水凝胶的变形和断裂联系起来

• 批准号: 1903308
• 负责人: Chung-Yuen Hui
• 金额: $ 63.78万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903308&HistoricalAwards=false
• 关键词: Connecting; Bond; breaking; Healing; Kinetics

A hydrogel is a soft material that is mostly water. One can think of a hydrogel as a three dimensional "fishnet" consisting of gelatin molecular chains (network) swollen by water drawn into the net. Hydrogels have many current applications such as contact lenses and as scaffolding materials for tissue engineering. Potential future applications may include artificial cartilage and "muscles" for soft robots. A shortcoming of simple hydrogels is that they are easy to fail; this severely limits their practical use in load bearing components. In recent years, chemists have invented hydrogels that are highly resistant to fracture. The network of this new class of hydrogels consists of molecular chains linked to each other by different types of connectors (bonds). These connectors can be permanent or temporary. Temporary connectors can break and reform. This process dissipates energy which contributes to resistance to fracture and they also allow the gel to heal. Currently, engineers do not have the predictive tools to determine how components made of these hydrogels change shape under load and when they break. This project will develop such predictive tools. The end product will be a quantitative method and a computer code which allows engineers to design and analyze components made of these hydrogels. Two long standing problems in the time dependent mechanics of deformation and fracture of soft materials are: (1) three dimensional large deformation nonlinear viscoelasticity and (2) efficient integration of these three dimensional nonlinear viscoelastic equations. A new idea to be explored by this research is that nonlinear viscoelasticity shields the crack from high stresses and thus enhances toughness. This project will address these issues by: (a) performing experiments on a tough Polyampholyte hydrogel, (b) developing quantitative models relating nonlinear viscoelastic behavior to bond breaking and reformation kinetics, (c) developing experimental methods to discover and to quantify crack shielding and (d) developing efficient time integration schemes to solve the nonlinear viscoelastic equations. The project will advance the field of mechanics by building a framework for development of time dependent constitutive and fracture models that are linked directly to the microstructure and that can be used in practical finite element simulations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

水凝胶是一种主要是水的柔软材料。 人们可以将水凝胶视为由明胶分子链（网络）组成的三维“渔网”，所述明胶分子链（网络）被吸入网中的水溶胀。 水凝胶目前有许多应用，如隐形眼镜和作为组织工程的支架材料。 未来潜在的应用可能包括用于软机器人的人造软骨和“肌肉”。 简单水凝胶的缺点是它们容易失效;这严重限制了它们在承载部件中的实际应用。 近年来，化学家发明了高度抗断裂的水凝胶。 这种新型水凝胶的网络由通过不同类型的连接器（键）彼此连接的分子链组成。 这些连接器可以是永久性的或临时的。 临时连接器可能会断裂和改革。 这个过程消耗了有助于抵抗断裂的能量，并且它们还允许凝胶愈合。 目前，工程师还没有预测工具来确定由这些水凝胶制成的组件在负载下如何改变形状以及何时破裂。 该项目将开发此类预测工具。 最终产品将是一种定量方法和计算机代码，允许工程师设计和分析由这些水凝胶制成的组件。 软材料变形与断裂力学中的两个长期存在的问题是：（1）三维大变形非线性粘弹性和（2）三维非线性粘弹性方程的有效积分。 本研究探索了一种新的思路，即非线性粘弹性屏蔽了高应力下的裂纹，从而提高了韧性。 该项目将通过以下方式解决这些问题：（a）对坚韧两性聚电解质水凝胶进行实验，（B）开发非线性粘弹性行为与键断裂和重组动力学相关的定量模型，（c）开发实验方法来发现和量化裂纹屏蔽，以及（d）开发有效的时间积分方案来求解非线性粘弹性方程。 该项目将通过建立与微观结构直接相关并可用于实际有限元模拟的时间相关本构和断裂模型的开发框架来推进力学领域。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估而被认为值得支持。

项目成果

Size effect on elastic stress concentrations in unidirectional fiber reinforced soft composites

• DOI: 10.1016/j.eml.2019.100573
• 发表时间: 2019-11-01
• 期刊: EXTREME MECHANICS LETTERS
• 影响因子: 4.7
• 作者: Hui, Chung-Yuen;Liu, Zezhou;Phoenix, S. Leigh
• 通讯作者: Phoenix, S. Leigh

Metamodeling of constitutive model using Gaussian process machine learning

• DOI: 10.1016/j.jmps.2021.104532
• 发表时间: 2021-09
• 期刊: Journal of the Mechanics and Physics of Solids
• 影响因子: 5.3
• 作者: Jikun Wang;Tianjiao Li;Fan Cui;C. Hui;Jingjie Yeo;A. Zehnder

Load transfer between permanent and dynamic networks due to stress gradients in nonlinear viscoelastic hydrogels

由于非线性粘弹性水凝胶中的应力梯度导致永久网络和动态网络之间的负载传递

• DOI: 10.1016/j.eml.2022.101928
• 发表时间: 2023
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: Wang, Jikun;Cui, Kunpeng;Zhu, Bangguo;Gong, Jian Ping;Hui, Chung-Yuen;Zehnder, Alan T.
• 通讯作者: Zehnder, Alan T.

Delayed fracture caused by time-dependent damage in PDMS

• DOI: 10.1016/j.jmps.2023.105459
• 发表时间: 2023-10
• 期刊: Journal of the Mechanics and Physics of Solids
• 影响因子: 5.3
• 作者: Jikun Wang;Bangguo Zhu;Chung-Yuen Hui;A. Zehnder

Mapping deformation and dissipation during fracture of soft viscoelastic solid

绘制软粘弹性固体断裂过程中的变形和耗散

• DOI: 10.1016/j.jmps.2024.105595
• 发表时间: 2024
• 期刊: Journal of the Mechanics and Physics of Solids
• 影响因子: 5.3
• 作者: Qi, Yuan;Li, Xueyu;Venkata, Sairam Pamulaparthi;Yang, Xingwei;Sun, Tao Lin;Hui, Chung-Yuen;Gong, Jian Ping;Long, Rong
• 通讯作者: Long, Rong