Exact component-wise solutions for 3D free vibration and stress analysis of hybrid steel-concrete composite beams

This paper presents the analysis of free vibration and stress state of steel-concrete composite beams, using high-order theories and closed-form solutions based on Carrera unified formulation (CUF). The governing differential equations are formulated in terms of fundamental nuclei via CUF and the longitudinal differential problem is solved analytically by imposing simply supported boundary conditions. For the cross-sectional kinematics approximation, bilinear, cubic, and fourth-order Lagrange polynomials are adopted. In particular, the component-wise (CW) approach is applied in which the steel part and concrete part are considered as two independent components. To assess the efficiency of the proposed method, I-section and box-section composite beams are studied. The results are compared with those from other research and the commercial software ABAQUS. From accuracy, it is clear that, albeit the proposed approach is 1D, it can provide 3D accuracy, in terms of both free vibration and stress analysis of steel-concrete composite beams, with a significant reduction in the computational costs, which is innovative and worth promoting.