论文：An energy-based assessment on dynamic amplification factor&n(2014-10-23 19:11:46)
Li Y, Lu XZ, Guan H, Ye LP,
Advances in Structural Engineering, 2014, 17(8): 1217-1225.
Figure 1 The RC frame structure under the beam mechanism
Abstract: Progressive collapse is a mechanical process that exhibits nonlinear and dynamic characteristics. The nonlinear dynamic effect on the progressive collapse resistance demand can be accurately evaluated by the nonlinear dynamic (ND) method. In engineering practice, however, the simplified and easy-to-use linear static (LS) method is often adopted. That is accomplished by using a dynamic amplification factor (DAF) to correct the LS resistance demand to approximate the true ND resistance demand. In this paper, the analytical expression of the DAF is established based on the energy conservation principle. The collapse-resisting substructure is firstly simplified as a single-degree-of-freedom (SDOF) equivalent. Then the energy conservation equation and the static balance equation of the SDOF equivalent are established to obtain the ND and LS demands. Finally, the DAF is obtained by dividing the ND demand by the LS demand. The DAF is validated through a series of the numerical examples including a SDOF system, a 3-storey planar frame and an 8-storey 3-D RC frame model structures.
Keyword: ductile RC frame structure, progressive collapse resistance demand, dynamic amplification factor, energy conservation principle
Figure 3 Numerical verification using a SDOF system
Figure 9 Structural resistance demand of three 8-storey RC frame structures