Research on drop hammer impact test of all-lightweight concrete beams with different steel fiber contents
Due to the low shear capacity of all-lightweight concrete structures,it is necessary to explore the influence of steel fiber on the dynamic performance of all-lightweight concrete beams.A total of three beams with steel fiber volume content of 0%,1%and 2%were designed,and the drop hammer impact test was carried out on the mid-span region.And using LS-dyna finite element software for numerical simulation.The failure modes,impact force time history curves and mid-span displacement time history curves of each specimen were compared and analyzed.The test results show that under the same impact load,with the increase of the volume fraction of steel fiber,the phenomenon of inhibiting the generation and development of cracks is more significant,and the cracks are relatively more concentrated in the middle area of the beam span,and the cracks at the support are relatively reduced.The addition of steel fiber does not affect the maximum impact force of the specimen,but with the increase of the volume content of steel fiber,the ratio of the second peak to the maximum impact force of each specimen increases by 14%and 26%,and the maximum mid-span displacement and residual displacement decrease by 3 mm and 8 mm,and 3 mm and 7 mm,respectively.The experimental study shows that the addition of steel fiber significantly improves the impact resistance of all-lightweight concrete beams.
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维普
