The slab spatial composite effect (SSCE) is of considerable importance in the field of engineering as it greatly influences the vertical load-bearing capacity and lateral load resistance of composite frame structures. In this study, the existing uniaxial material-constitutive models of concrete (Concrete02) and steel (Steel02) in the Open System for Earthquake Engineering Simulation (OpenSees) were modified based on three effective flange widths of composite beams under two critical limit states. An improved fiber model was developed to capture the SSCE of composite frames by combining the conventional fiber models and new material-constitutive models. Through three validation studies, the ability of the proposed fiber model to trace the SSCE accurately and efficiently was established based on modeling and comparison of the representative composite frames available in literature. Moreover, seismic fragility assessment was conducted for a 10-story spatial composite frame subjected to bidirectional horizontal seismic excitation based on an incremental dynamic analysis. The comprehensive numerical simulation results indicate that the conventional fiber model without constitutive model modifications leads to significant overestimation of the probability of the structure being a specified limit state under different ground motion intensities and site classes. The conventional fiber model results are at most 47.1%, 72.0%, 53.5%, and 49.6% higher than those obtained using the improved fiber model in terms of the structure being slightly, moderately, extensively, and completely damaged, respectively. This means that the potential economic advantages of composite frames can be explored by reasonably considering the SSCE.

板空间复合效应（SSCE）在工程领域具有相当重要的意义，因为它极大地影响了复合框架结构的垂直承载能力和侧向承载能力。在本研究中，现有的混凝土 ( Concrete02 ) 和钢 ( Steel02) 在地震工程模拟开放系统 (OpenSees) 中基于两个临界极限状态下组合梁的三个有效翼缘宽度进行了修改。通过结合传统的纤维模型和新的材料本构模型，开发了一种改进的纤维模型来捕获复合框架的 SSCE。通过三项验证研究，基于文献中可用的代表性复合框架的建模和比较，建立了所提出的纤维模型准确有效地跟踪 SSCE 的能力。此外，基于增量动力分析，对受双向水平地震激发的10层空间复合框架进行了地震脆性评估。综合数值模拟结果表明，没有本构模型修改的常规纤维模型导致结构在不同地震动强度和场地类别下成为指定极限状态的概率的显着高估。常规纤维模型的结果在结构轻微、中度、广泛和完全破坏方面分别比使用改进的纤维模型得到的结果高47.1%、72.0%、53.5%和49.6%。这意味着可以通过合理考虑 SSCE 来探索复合框架的潜在经济优势。常规纤维模型的结果在结构轻微、中度、广泛和完全破坏方面分别比使用改进的纤维模型得到的结果高47.1%、72.0%、53.5%和49.6%。这意味着可以通过合理考虑 SSCE 来探索复合框架的潜在经济优势。常规纤维模型的结果在结构轻微、中度、广泛和完全破坏方面分别比使用改进的纤维模型得到的结果高47.1%、72.0%、53.5%和49.6%。这意味着可以通过合理考虑 SSCE 来探索复合框架的潜在经济优势。