Abstract: Borrowing the idea of load/unload response theory in seismic prediction, seismic dynamic model is established, in which seismic acceleration on the boundary is regarded as load/unload process and relative displacement, velocity or acceleration is looked upon as response parameters, whole time history analysis is performed by finite element method and load/unload response theory, favourable exploratory of the application in dynamic response prediction is then attained through the above-mentioned theories. The results indicate that relative response parameters are more applicable of describing structure deformation, reflecting the dynamic mechanism of action than absolute displacement. Using Load/unload dynamic response ratio to identify the damage degree under seismic waves turns out to be an effective method reflecting the response degree.

Key words: dynamic response, load/unload law, absolute dynamic response, relative dynamic response