Abstract: The polyline force restoring model is commonly used in explaining the constitutive relation structure for the seismic elasticplastic time history analysis, and  the inflection point processing directly affects the accuracy of the structural seismic response. The linear interpolation method was used in the inflection point processing, and the characteristics of the multi degree freedom system were combined,  which enabled the inflection point processing method to meet the requirements for program calculation in the structural seismic response. It provides a multi degree freedom layer model for the elastic-plastic time history analysis, and compares the results of the inflection point processing with those when the inflection point is not processed. Eventually,  it analyses systematically the influence of the inflection point processing on the amplitude, frequency and phase of the structural seismic response. 

Key words: force restoring model; inflection point processing; elastic-plastic dynamic analysis