| Summary: | 碩士 === 國立臺北科技大學 === 土木與防災研究所 === 95 === It is accepted that the ultimate lateral force of reinforced concrete columns is the 80% maximum lateral force of hysteresis loops evaluated by the cyclic loading test. However, this method is not theoretically supported. Thus, this study aimed to create a new method to evaluate ductility of reinforced concrete columns by applying the concept of cycle energy dissipation. Our method was to count the area of each hysteresis loop derived from the cyclic loading test, and the area represented the energy of reinforced concrete columns dissipated in that cycle. Then, the figures of cycle energy dissipation capacity were made orderly according to the energy dissipated in each cycle. Besides, the term "unit displacement dissipation cycle energy capacity" in this study was the energy dissipated in unit displacement of each cycle. When the unit displacement dissipation cycle energy capacity became maximal, the specimen was regarded destroyed. Therefore, the homologous maximum lateral force and maximum displacement individually represented ultimate lateral force and ultimate displacement. Moreover, when the specimen bore ultimate lateral force, a certain percentage of the dissipating energy was defined as the energy that reinforced concrete columns could dissipate when yielding. As a result, the displacement of the cycle homologizing the dissipating energy when yielding became yield displacement. After getting ultimate displacement and yield displacement, were attained the ductility could be evaluated. In order to test the validity of the new method, the data of cyclic loading test were collected and analyzed to get the ultimate lateral force. The accepted method and our method were both applied and then the comparison of two methods was made to get the differences. This study intended to create a systematic method to evaluate ductility strength.
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