The differences in the mechanical performance of prismatic and non-prismatic beams with corrugated steel webs: A comparative research

摘要

The differences in the mechanical performance of prismatic and non-prismatic beams with concrete flanges and corrugated steel webs (CSWs) are numerically investigated in this paper with respect to their behaviour in bending, shear and shear buckling. With regard to the bending behaviour, it is found that the quasi-plane assumption is still valid for the non-prismatic beams with CSWs, similar to the prismatic beams with CSWs, at their elastic stage and their bending stiffness are mainly provided by the concrete flanges. This is attributed to the accordion effect of such webs. In terms of the shear behaviour, it is found that the inclined bottom flange shares a significant portion of the shear force in the non-prismatic beam with CSW, while the effective shear force carried by the CSW is greatly reduced; this phenomenon is called the Resal effect which is the most important reason leading to the shear performance difference between the prismatic and non-prismatic beams with CSWs. Thus, the traditional calculation assumption that the CSWs bear all the vertical shear force in the prismatic beams with CSWs is no longer applicable in calculating the shear stress in the non-prismatic cases. Additionally, it is noticed from two numerical cases, simulating the prismatic and non-prismatic beams with CSWs under end loading, that the average shear stress in the CSW of the non-prismatic beam decreases gradually from the free-end to the fixed-end with the increase of the hogging bending moment, while the shear stress in the CSW remains nearly constant in the prismatic beam. The numerical results, as well, show that the root cross-section, although it bears the maximum bending moment and shear force, is not the critical shear section of the CSW of the non-prismatic beam. Finally, considering the shear buckling behaviour, it is found that the shear buckling stress of the non prismatic with CSW is much greater than that of an equal-weight prismatic beam with CSW through eigenvalue buckling analyses.