NUMERICAL ANALYSIS OF IN-PLANE SHEAR BEHAVIOR OF SC WALLS UNDER COMBINED LOADINGS

Steel-concrete composite (SC) walls are increasingly gaining interest as an alternative to reinforced concrete (RC) walls for safety-related nuclear facilities. The major loading for the SC design is seismic loading. Seismic loading results in combined in-plane shear with axial or out-of-plane moment loading on SC structures. The primary resistance against the lateral loading in these structures is provided by in-plane shear resistance. While the AISC N690 design code includes equations for determining in-plane shear capacity and combined loading, its guidance is limited to pure in-plane shear capacity, in-plane shear combined with out-of-plane moments and combined out-of-plane shear forces. It lacks comprehensive design equations for combined loadings, such as in-plane shear with axial or out-of-plane moment loading. Additionally, the N690 design equation for in-plane shear capacity is somewhat conservative. Understanding the behavior of SC walls under these combined loadings is crucial for their optimal design.

This research addresses this gap by performing numerical investigation based on the finite element modelling (FEM) and mechanics-based approaches to analyze the behavior of SC walls under these loadings. The models were verified and validated using data from previous experimental studies. A parametric study was conducted to evaluate the impact of various design and material parameters on the in-plane shear capacity under combined loadings. Based on the parametric data and linear regression analysis, design equations were formulated to predict the in-plane shear capacity. Interaction envelopes were developed to compare the results from these models with those from previous numerical studies. Finally, practical design guidance and design equations were provided to design these structures.