Civil and Environmental Engineering Department, University of Waterloo, Waterloo, Ontario, Canada.
Mechanical and Mechatronics Engineering Department, University of Waterloo, Waterloo, Ontario, Canada.
PLoS One. 2020 May 12;15(5):e0233021. doi: 10.1371/journal.pone.0233021. eCollection 2020.
The time-dependent properties of rubber-like synthesized and biological materials are crucial for their applications. Currently, this behavior is mainly measured using axial tensile test, compression test, or indentation. Limited studies performed on using multi-axial loading measurements of time-dependent material behavior exist in the literature. Therefore, the aim of this study is to investigate the viscoelastic response of rubber-like materials under multi-axial loading using cavity expansion and relaxation tests. The tests were performed on PVA hydrogel specimens. Three hyperelasitc models and one term Prony series were used to characterize the viscoelastic response of the hydrogels. Finite element (FE) simulations were performed to verify the validity of the calibrated material coefficients by reproducing the experimental results. The excellent agreement between the experimental, analytical and numerical data proves the capability of the cavity expansion technique to measure the time-dependent behavior of viscoelastic materials.
橡胶类合成材料和生物材料的时变特性对于它们的应用至关重要。目前，这种行为主要通过轴向拉伸试验、压缩试验或压痕试验来测量。文献中有限的研究涉及使用多轴加载测量时变材料行为。因此，本研究的目的是使用腔扩张和松弛试验来研究橡胶类材料在多轴加载下的黏弹性响应。试验是在 PVA 水凝胶试件上进行的。使用三种超弹性模型和一个 Prony 级数来描述水凝胶的黏弹性响应。通过再现实验结果，有限元（FE）模拟验证了校准材料系数的有效性。实验、分析和数值数据之间的良好一致性证明了腔扩张技术测量黏弹性材料时变行为的能力。
