The Finite Element Analysis of the Influence of Cast-in-place Floor on the Dynamic Characteristics of RC Frame Structure

Using the 3D FE modeling, natural vibration of a RC frame with cast-in-place slabs and a RC frame without floor slabs were analyzed to investigate the influence of the cast-in-place slab on the dynamic characteristics of the frame. The fundamental period determined from the numerical analysis of the RC frame with cast-in-place slabs was agree with that determined from design software PKPM, verifying the reliability of the calculation model. The comparison of vibration modes and periods between pure frame and the frame with slabs shows that the cast-in-place slabs enhance the lower-order periods and reduce the higher-order periods. The influence of the cast-in-place slabs on the higher-order modes is larger than that of on the lower-order modes. Based on the analysis result, the good function of the case-in-place slabs should be considered in the practical engineering structure design.