摘要: | 根據過去經驗,傳統有限元素法在面對大量非線性的問題時容易產生數值發散問題,導致分析時間過長或是無法順利完成分析,為解決此問題本研究使用基於等效節點割線特性之隱式動力分析程序(Implicit Dynamic Analysis Procedure based on Equivalent Nodal Secant Properties, IDAP-ENSP)。 本研究分析之模型為位於台中之5層樓鋼筋混凝土建物,因其建造年代較為久遠,分析上應考慮到其勁度衰減之情形,因此本研究新增Modified Takeda模型進入IDAP-ENSP中,並由於梁斷面上下層配筋量不同,吾將模型改善為可考慮斷面上下層配筋不同情形。 分析上雖然非線性動力歷時分析能夠更真實的反應結構物面臨地震作用下之實際行為,但非線性動力歷時分析較為繁複且礙於現今市面上可用軟體其計算上耗時且容易數值發散,且難以模擬建物破壞後之高度非線性之行為,因此使用上較為困難,因此工程師較習慣以非線性靜力分析代替。本研究將考慮目標建物倒塌破壞前之行為,並分析1.未隔震 2.使用FPS隔震 3.使用PFPI隔震,與(1)使用Takeda模型(2)使用Modified Takeda模型作為塑鉸遲滯行為之建物。可得知使用PFPI之隔震效果最佳,其次FPS最後是未隔震建物;遲滯模型的選用上因本研究建物年代較為久遠,房屋會有所損傷耐震能力會衰減因此使用Modified Takeda較為合適。 本研究亦比較傳統使用性能設計考慮層間變位之方式與本研究直接設定構件降伏、破壞行為之關聯。可以發現考慮層間變位之結果本研究結論相符。 ;Based on past experience, traditional finite element methods tend to encounter numerical divergence issues when dealing with highly nonlinear problems, leading to prolonged analysis times or the inability to complete the analysis successfully. To address this issue, this study employs an Implicit Dynamic Analysis Procedure based on Equivalent Nodal Secant Properties (IDAP-ENSP). The model analyzed in this study is a five-story reinforced concrete building located in Taichung. Given its age, the analysis considers the stiffness degradation of the structure. Therefore, this study incorporates the Modified Takeda model into IDAP-ENSP. Additionally, due to the different reinforcement amounts in the upper and lower layers of the beam section, the model is improved to account for these differences. Although nonlinear dynamic time-history analysis can more realistically reflect the actual behavior of structures under seismic action, it is more complex and, given the current software available on the market, time-consuming in calculation and prone to numerical divergence. Moreover, it is difficult to simulate highly nonlinear behavior after the building′s failure, making its use more challenging. As a result, engineers often prefer nonlinear static analysis instead. This study considers the behavior of the target building before collapse and analyzes three scenarios: 1. without seismic isolation, 2. with FPS seismic isolation, and 3. with PFPI seismic isolation. It also examines the building′s plastic hinge hysteretic behavior using (1) the Takeda model and (2) the Modified Takeda model. The results show that PFPI provides the best seismic isolation, followed by FPS, and lastly, the building without seismic isolation. Given the building′s age, which may lead to reduced seismic resistance due to damage, the Modified Takeda model is more appropriate. ii This study also compares the traditional performance design method, which considers inter-story displacement, with this study′s approach of directly setting the relationship between component yield and failure behavior. It is found that the results considering inter-story displacement are consistent with the conclusions of this study. |