Seismic response analysis of material nonlinearity of a concrete filled steel tube arch bridge

In this paper, material nonlinearity of CFST (concrete-filled-steel-tube) element is analyzed by combination element method and double element method, and the restoring force models of CFST material are given by the both methods. Nonlinear seismic response of CFST arch bridge is analyzed by the both methods. The results of the combination element method and the double element method are very approximate, and the both methods are effective methods of nonlinear analyses. Comparison with the result of linear analysis indicate that the effect of material nonlinearity on seismic performance of CFST arch bridge is notable.