This article analyses the conditions for the yield stress state of concrete subjected to generalised loads. For this purpose, a limit stress state criterion, initially developed for the assessment of magnesium and respective alloys, is here adapted and implemented as a simulation model to assess the structural integrity of concrete components. In fact, materials as magnesium and concrete exhibit a similar mechanical behaviour, presenting a non-symmetric limit state domain for biaxial stress combinations, where it is observed a considerably larger strength to yield or rupture in a compression stress state than in a tensile one. The Cazacu yield stress state criterion has shown to be an accurate and realistic model to define the ultimate strength, either of concrete and magnesium alloys, as mentioned. The Cazacu criterion was implemented in a finite element program as a ‘user-defined’ subroutine. The numerical validation of that criterion was carried out on adjusting its limit stress state points to corresponding ones obtained by experiments of standard tensile or compression tests of concrete test specimens.

中文翻译：

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混凝土不对称行为的数值模拟

本文分析了混凝土在广义荷载作用下屈服应力状态的条件。为此，最初为评估镁和相应合金而开发的极限应力状态标准在此被改编并实施为模拟模型，以评估混凝土部件的结构完整性。事实上，镁和混凝土等材料表现出类似的机械行为，呈现出双轴应力组合的非对称极限状态域，在压缩应力状态下观察到的屈服或断裂强度比拉伸状态大得多。如前所述，Cazacu 屈服应力状态标准已被证明是定义混凝土和镁合金极限强度的准确且现实的模型。Cazacu 准则作为“用户定义”子程序在有限元程序中实现。该准则的数值验证是通过将其极限应力状态点调整为通过混凝土试样的标准拉伸或压缩试验获得的相应值来进行的。