The mechanical behavior of rubber-like materials is dominantly non-linear elastic. Their mechanical response is measured by numerous conventional techniques including the universal loading machines (tension and compression) and indentation. Recently, an unconventional technique based on cavitation rheology has been implemented to measure the mechanics of these materials. The loading mechanism of this technique is different from the axial force–displacement mechanism observed in the other techniques thus the aim of this study is to investigate the difference between the cavity expansion technique and one of the conventional techniques, uniaxial stretching, to understand the difference in material responses under each loading mechanism. PVA hydrogel was used as a representative to hyperelastic materials. The gels were loaded by both techniques, and hyperelastic models (Yeoh, Ogden, and Arruda–Boyce) were used to model their behavior. Finite Element (FE) simulations were performed to reproduce the experimental data. It was observed that the tension stresses generated during the cavity expansion test were similar to those generated in the uniaxial tension to a strain level of 45%, afterward, the cavity tension stresses increased exponentially exceeding those generated in the uniaxial tension. When the von Mises stresses, from both tests, were compared against the major tension stress data, it was observed that the cavity test imposed tension stresses that were twice of those generated during the uniaxial tensile test. In addition, the hoop stresses were significantly larger than the applied pressure. These observations indicate to the equi-biaxial nature of the cavity expansion test.

橡胶状材料的机械性能主要是非线性弹性。它们的机械响应是通过许多常规技术测量的，包括通用装载机（拉伸和压缩）和压痕。最近，已经实施了一种基于空化流变学的非常规技术来测量这些材料的力学性能。该技术的加载机制不同于其他技术中观察到的轴向力-位移机制，因此，本研究的目的是研究型腔扩张技术与传统技术之一（单轴拉伸）之间的差异，以了解其差异。在每种加载机制下的材料响应。PVA水凝胶被用作超弹性材料的代表。通过两种技术加载凝胶，并使用超弹性模型（Yeoh，Ogden和Arruda-Boyce）对它们的行为进行建模。进行了有限元（FE）模拟以重现实验数据。观察到，在腔膨胀试验期间产生的拉应力与在单轴拉伸中产生的拉应力相似，至45％的应变水平，之后，腔拉应力以指数方式增加，超过在单轴拉伸中产生的拉应力。将两个测试的von Mises应力与主要拉应力数据进行比较时，可以观察到模腔测试施加的拉应力是单轴拉伸测试中产生的两倍。另外，环向应力明显大于施加的压力。这些观察表明腔膨胀试验的等双轴性质。