| Summary: | 碩士 === 逢甲大學 === 土木工程所 === 96 === The deformation characteristic of structures under earthquake excitations, has pointed out the destruction of the building is mainly damaged by the low cycle fatigue. The accumulation of this form of damages in the components of the structure, which excurses the plasticity state repeatedly, will result in rupturing of components or even collapse of the whole structure.
This study applied the dynamic theory and cyclic counting method. Choosed 921 procedure to analyze the cycle number demands of structures under earthquake excitation. In the analysis, single-degree-of-freedom (SDOF) systems with 10 varied natural periods were considered, near-fault as well as far-distant earthquake data were chosen from (Che-Lung-Pu) earthquake. The linear and nonlinear displacement response histories were generated before the ductility ratios, the maximum displacement ranges and the equivalent cyclic demands were obtained, using the rain-flow counting procedure. It is found that, taking ductility ratio=4.8 as an example, most cyclic demands are less than 20 and varies for different earthquake data and structural periods.
|
|---|
