聚电解质水凝胶的电-化-力耦合瞬态非线性有限元框架及实现
A transient nonlinear finite element framework and implementation of coupled electro-chemo-mechanics of polyelectrolyte hydrogels
AI总结：
本研究开发了电-化-力耦合瞬态非线性有限元框架，在Abaqus/Standard中以UEL子程序实现聚电解质水凝胶模型，经实验验证后用于研究其溶胀、固结及弯曲行为，明确了关键影响因素。
AI中文摘要：
聚电解质（PE）水凝胶表现出复杂行为，特征为大机械变形、非线性应力响应、溶剂传输及离子扩散，这些机制的相互作用会引发意外的溶胀动力学、变形模式和应力响应。因此，需要先进计算工具来高效设计基于PE水凝胶的器件，如用于软机器人的致动器和传感器、微流控阀及药物递送系统。本研究开发了一种数值框架，用于通过有限元分析模拟PE水凝胶的电-化-力耦合行为。应用该框架，在Abaqus/Standard中以用户单元（UEL）子程序形式实现了稀离子溶液中PE水凝胶的电-化-力模型。通过与文献中DMAEA水凝胶在不同离子强度溶液中的瞬态自由溶胀实验对比，验证了该模型及UEL实现；随后将其用于研究受限压缩下的固结行为及水凝胶双层的瞬态弯曲行为。模拟结果表明，外部溶液的离子强度、固定电荷密度和Flory-Huggins参数对瞬态溶胀和固结行为的幅度有显著影响。
英文摘要：
Polyelectrolyte (PE) hydrogels exhibit complex behavior characterized by large mechanical deformations, nonlinear stress response, solvent transport, and ion diffusion. The interplay between these mechanisms can lead to unexpected swelling dynamics, deformation patterns, and stress response. As such, advanced computational tools are needed for the efficient design of PE hydrogel-based devices, such as actuators and sensors for soft robotics, microfluidic valves, and drug delivery systems. In this work, we develop a numerical framework to simulate the coupled electro-chemo-mechanical behavior of PE hydrogels using finite element analysis. Applying this framework, an electro-chemo-mechanical model for PE hydrogels in a dilute ionic solution is implemented as a user element (UEL) subroutine in Abaqus/Standard. The model and UEL implementation are validated by comparing to experiments in the literature for transient free-swelling of a DMAEA gel in a solution of varying ionic strengths, then applied to study the consolidation behavior under confined compression and the transient bending behavior of a hydrogel bilayer. The simulations show that the ionic strength of the external solution, fixed charge density, and Flory-Huggins parameter play significant roles in the magnitude of the transient swelling and consolidation behavior.
