In this paper, modelling of the superposition of stress-induced and inherent anisotropy of soil small strain stiffness is presented in the framework of hyperelasticity. A simple hyperelastic model, capable of reproducing variable stress-induced anisotropy of stiffness, is extended by replacement of the stress invariant with mixed stress–microstructure invariant to introduce constant inherent cross-anisotropic component. A convenient feature of the new model is low number of material constants directly related to the parameters commonly used in the literature. The proposed description can be incorporated as a small strain elastic core in the development of some more sophisticated hyperelastic-plastic models of overconsolidated soils. It can also be used as an independent model in analyses involving small strain problems, such as dynamic simulations of the elastic wave propagation. Various options and features of the proposed anisotropic hyperelastic model are investigated. The directional model response is compared with experimental data available in the literature.

在超弹性的框架下，提出了应力应变和固有应变各向异性对土壤小应变刚度的叠加作用的建模方法。一个简单的超弹性模型，能够重现可变的应力诱发的各向异性，并通过用混合的应力-微观结构不变性代替应力不变性而引入恒定的固有交叉各向异性分量，从而扩展了模型。新模型的一个便利功能是与文献中通常使用的参数直接相关的少量材料常数。拟议的描述可以作为小应变弹性芯纳入超固结土的一些更复杂的超弹塑性模型的开发中。在涉及小应变问题的分析中，它也可以用作独立模型，例如弹性波传播的动态模拟。研究了提出的各向异性超弹性模型的各种选择和特征。将方向模型的响应与文献中提供的实验数据进行了比较。