Comparative assessment of element types for evaluating local elastic buckling behavior of rectangular hollow sections using finite element analysis

This study systematically evaluates the performance of conventional shell elements in Abaqus for predicting the local elastic buckling behavior of rectangular hollow sections (RHSs) under various loading conditions, including axial compression, major axis bending, and minor axis bending. Theoretical local buckling coefficients were first derived based on the cross-sectional dimensions of RHSs and used to calculate the critical local buckling stress for each loading scenario. Finite element analyses (FEA) were then performed using different shell element types, including four-node and eight-node elements, to assess their accuracy and computational efficiency. The results indicate that four-node shell elements (S4, S4R) offer a favorable balance of accuracy and significantly reduced computational time, making them the most efficient option. In contrast, eight-node elements (S8R, S8R5) provide marginally higher accuracy but require substantially longer computation times and have limited applicability. This study underscores the importance of selecting appropriate elements to achieve a balance between accuracy and efficiency, providing valuable guidance for engineers in structural design. By optimizing element selection for modeling local elastic buckling in RHSs, the research improves computational efficiency and supports the development of more reliable, cost-effective designs.