Behaviors of Steel and Composite Beams at Various Displacement Rates

Abstract

The influence of displacement rates on elastic‐plastic behaviors of structural members was investigated using dynamic tests and quasi‐static tests. Monotonic and cyclic reversed tests of steel beams and fully composite beams were conducted at three displacement rates: 0.15 cm/s, 15 cm/s and 30 cm/s. Significant differences in the maximum moment capacities of steel beams and composite beams were found between the quasi‐static and dynamic behavior under both monotonic and cyclic loadings. The elastic stiffness and the unloading stiffness in the plastic range were not influenced by the displacement rates. Although deformation capacities of steel beams tended to increase slightly with an increase in displacement rates, no substantial qualitative differences were observed under either monotonic or cyclic loadings. In this paper viscous damping of steel beams in the elastic range is also discussed in order to clarify the increase in the maximum moment capacities.