Mechanical characterization of soft viscoelastic gels via indentation and optimization-based inverse finite element analysis
Mechanical characterization of soft viscoelastic gels via indentation and optimization-based inverse finite element analysis
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DOI：
10.1016/j.jmbbm.2008.12.001
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发表时间：
2009-08-01
影响因子：
3.9
通讯作者：
Ovaert, Timothy C.
中科院分区：
文献类型：
--
作者：
Liu, Kaifeng;VanLandingham, Mark R.;Ovaert, Timothy C.
聚合物凝胶被广泛认为是组织工程、药物输送和骨科承重应用的候选材料。此外，它们的机械和物理性能可以定制以满足广泛的设计要求。对于弹性模量在 kPa 范围内的软凝胶，通过整体机械测试方法进行机械表征面临着挑战，例如在样品制备、夹具设计、夹持和/或负载测量精度方面。然而，纳米压痕在表征软材料的机械性能时具有优势。本研究旨在研究逆有限元分析技术的应用，通过纳米压痕蠕变测试、优化和有限元模拟来识别聚合物凝胶的材料参数。使用刚性圆形平冲头进行纳米压痕实验，然后使用商业软件ABAQUS(TM)进行模拟。使用 Matlab (TM) shell 程序将优化（误差最小化）程序集成到参数确定过程中，这使得该方法很容易适应其他测试几何形状和材料模型。有限元结果与 Kelvin-Voigt 半空间上刚性圆形平冲头的导出解析粘弹性解相比较。 (C) 2008 Elsevier Ltd. 保留所有权利。
Polymer gels are widely accepted as candidate materials for tissue engineering, drug delivery, and orthopedic load-bearing applications. In addition, their mechanical and physical properties can be tailored to meet a wide range of design requirements. For soft gels whose elastic modulus is in the kPa range, mechanical characterization by bulk mechanical testing methods presents challenges, for example, in sample preparation, fixture design, gripping, and/or load measurement accuracy. Nanoindentation, however, has advantages when characterizing the mechanical properties of soft materials. This study was aimed at investigating the application of an inverse finite element analysis technique to identify material parameters of polymer gels via nanoindentation creep testing, optimization, and finite element simulation. Nanoindentation experiments were conducted using a rigid circular flat punch, and then simulated using the commercial software ABAQUS (TM). The optimization (error minimization) procedure was integrated in the parameter determination process using a Matlab (TM) shell program, which makes this approach readily adaptable to other test geometries and material models. The finite element results compare well with a derived analytical viscoelastic solution for a rigid circular flat punch on a Kelvin-Voigt half-space. (C) 2008 Elsevier Ltd. All rights reserved.