Improved Analytical Method to Investigate the Dynamic Characteristics of Composite Box Beam with Corrugated Webs

摘要

This study establishes an improved analytical method (IAM) to investigate the dynamic characteristics of composite box beam with corrugated webs (CBBCW), and the IAM has comprehensively considered the effects of several factors, such as the shear lag, interfacial slip, shear deformation and rotational inertia of CBBCW in combination with the characteristics of CBBCW. Further, based on the Hamilton principle, the vibration differential equation and boundary conditions for CBBCW have been deduced. Finally, an IAM for calculating the dynamic characteristics of CBBCW was proposed. Based on the IAM developed in this study, the natural frequencies of multiple CBBCW cases with different spans, shear connection degrees and boundary conditions have been calculated. The results calculated by the IAM have been compared with those calculated by the finite element method and by the general beam theory. The comparison verifies the effectiveness of the IAM and obtains some conclusions that are meaningful to engineering design, i.e. the shear lag effect of CBBCW increases with increasing shear connection degree and also increases with increasing order of the vibration mode, the shear lag effect of the CBBCW is up to 6.2% in the first five orders of the vibration modes and the effect cannot be ignored. In the first- and second-order vibration modes of the CBBCW cases, the maximum interface slip effect of CBBCW is 28.42% and therefore cannot be ignored. On the other hand, the shear lag effect of CBBCW is usually lower than those of ordinary composite box beam with the same web thickness.