Abstract Parts of the irreversible response of materials can be described by a plasticity approach. For modelling quasi-brittle materials such as concrete, the microplane approach is a powerful method. In order to predict the load–displacement as well as the stress–strain relation, numerous constitutive models developed for small strains have been used successfully. Nevertheless, for example, at high hydrostatic pressure, extremely large deformations occur even in concrete materials with no damage or voids. As consequence, the microplane-plasticity model at small strains needs to be extended to the finite strain framework for largely deformed structures. The elastoplastic microplane approach based on the kinematic constraint of the volumetric-deviatoric split and the Drucker-Prager yield criterion at finite strains are implemented in the present work. Furthermore, due to strain localisation, an implicit gradient enhanced approach is applied in here to obtain stable and mesh insensitive solutions. Numerical examples including the comparison of simulated results to existing experimental data are provided to validate the proposed formulation.

中文翻译：

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基于微平面理论的有限应变混凝土非局部软化塑性

摘要 材料的部分不可逆响应可以用塑性方法来描述。对于模拟混凝土等准脆性材料，微平面方法是一种强大的方法。为了预测载荷-位移以及应力-应变关系，已经成功使用了许多针对小应变开发的本构模型。然而，例如，在高静水压力下，即使在没有损坏或空隙的混凝土材料中也会发生极大的变形。因此，小应变下的微平面塑性模型需要扩展到大变形结构的有限应变框架。在当前的工作中实施了基于体积-偏量分裂的运动学约束和有限应变下的 Drucker-Prager 屈服准则的弹塑性微平面方法。此外，由于应变局部化，此处应用了隐式梯度增强方法以获得稳定且网格不敏感的解决方案。提供了包括模拟结果与现有实验数据比较在内的数值示例，以验证所提出的配方。