In the computational efficiency context, combining response precision and low execution time, methods that consider concentrated non-linear effects are interesting. The refined plastic hinge method (RPHM) considers the plasticity effects exclusively at the nodal points of the finite element mesh, however, it was developed for steel structures, with elastic-perfectly plastic behavior. In this methodology, rotational pseudo-springs in the finite elements ends are responsible to introduce the flexural stiffness degradation due to material non-linearity while the one-dimensional elements remain in the elastic state. The present work aims to study the inclusion of the flexural stiffness degradation of steel–concrete composite structural elements under monotonic loads, considering the cracking effects through the Branson equation, coupled to RPHM. For this, it is necessary to delimit the uncracked and cracked behavior of the cross-section. Thus, the strain compatibility method was used, in which, through the study of the cross-sectional behavior, interaction curves are obtained for the determination of elastic/elasto-plastic/plastic and uncracked/cracked states. Furthermore, this proposition is applied in a displacement-based formulation for the evaluation of the global behavior of steel–concrete composite elements. Comparisons are made between the results obtained here and those available in the literature, in the experimental and numerical contexts. These comparisons indicated for the validation of the numerical procedure proposed and implemented here, highlighting the precision of the formulation in both the pre- and post-critical structures behavior.

在计算效率方面，结合响应精度和低执行时间，考虑集中非线性效应的方法很有趣。精细塑性铰法 (RPHM) 仅考虑有限元网格节点处的塑性效应，但它是针对钢结构开发的，具有完美弹塑性行为。在这种方法中，有限元端部的旋转伪弹簧会由于材料非线性而导致弯曲刚度下降，而一维单元仍处于弹性状态。目前的工作旨在研究单调荷载下钢-混凝土复合结构构件的弯曲刚度退化，通过与 RPHM 耦合的 Branson 方程考虑开裂效应。为此，有必要界定横截面的未开裂和开裂行为。因此，采用应变相容方法，通过研究横截面行为，获得相互作用曲线，用于确定弹性/弹塑性/塑性和未裂纹/裂纹状态。此外，该命题应用于基于位移的公式中，用于评估钢-混凝土复合元件的整体行为。在实验和数值背景下，对此处获得的结果与文献中提供的结果进行了比较。这些比较表明了此处提出和实施的数值程序的验证，突出了临界前和临界后结构行为中公式的精度。有必要对截面的未开裂和开裂行为进行界定。因此，采用应变相容方法，通过研究横截面行为，获得相互作用曲线，用于确定弹性/弹塑性/塑性和未裂纹/裂纹状态。此外，该命题应用于基于位移的公式中，用于评估钢-混凝土复合元件的整体行为。在实验和数值背景下，对此处获得的结果与文献中提供的结果进行了比较。这些比较表明了此处提出和实施的数值程序的验证，突出了临界前和临界后结构行为中公式的精度。有必要对截面的未开裂和开裂行为进行界定。因此，采用应变相容方法，通过研究横截面行为，获得相互作用曲线，用于确定弹性/弹塑性/塑性和未裂纹/裂纹状态。此外，该命题应用于基于位移的公式中，用于评估钢-混凝土复合元件的整体行为。在实验和数值背景下，对此处获得的结果与文献中提供的结果进行了比较。这些比较表明了此处提出和实施的数值程序的验证，突出了临界前和临界后结构行为中公式的精度。