橋梁受車輛移動載重作用下之調諧質量阻尼器最佳化設計

Abstract

伴隨著社會經濟的迅速發展，人民需透過通勤以抵達目的地，因此興建大量的橋梁、快速道路以滿足需求。當車輛通過橋梁時，橋面板的振動反應可能導致行車途中的不舒服，故在設計時除了滿足強度要求外，須考慮舒適度問題。目前建築結構中已廣泛使用各類型的阻尼器來抑制振動以及消能，其中調諧質量阻尼器為一常見之減震裝置，加裝後可以減少振動造成的不舒適感，提升舒適性。 本研究以橋梁做為主要研究之結構，利用建模軟體SAP2000建立一單跨雙車道之橋梁模型，在一向車道放置靜止不動之貨車質量，並使用分析軟體MATLAB，在另一向車道加載貨車移動載重，觀察橋梁中央的垂直向振動行為，並透過最佳化設計探討加裝TMD後對於加速度的折減效果。搭配ISO 2631-1規範中定義的舒適性指標:整體振動總值(OVTV)，觀察移動載重造成的舒適度等級，並比較不同目標函數下TMD設計參數的結果。此外，也利用整體振動總值當中最高的舒適性等級做為限制，以最小化TMD質量作為目標函數，求出滿足限制條件下時對應之TMD最小質量，以確保在滿足舒適性限制的條件下，能夠減少施工成本以及困難度，如此一來即可滿足營造方、使用者等需求。

With the rapid development of social economy, commuting has become essential for people to reach their destinations, leading to the construction of numerous bridges and expressways to meet demand. When vehicles pass over a bridge, the vibration response of the bridge deck can cause discomfort while driving. Therefore, in addition to meeting strength requirements, comfort must also be considered in the design process. Various types of dampers are widely used in structural engineering to suppress vibrations and dissipate energy, among which the Tuned Mass Damper (TMD) is a common vibration control device. The installation of TMDs can reduce the discomfort caused by vibrations and enhance comfort. This study focuses on bridges as the primary structure of interest. A single-span, two-lane bridge model is established using the modeling software SAP2000. A stationary truck mass is placed in one lane, while a moving truck load is applied to the other lane using MATLAB. The vertical vibration behavior at the center of the bridge is observed, and the reduction effect of acceleration due to TMD installation is investigated through optimal design. The comfort index defined by ISO 2631-1, namely the Overall Vibration Total Value (OVTV), is used to assess the comfort level caused by moving loads. The results of TMD design parameters under different objective functions are compared. Additionally, the highest comfort level in the OVTV is used as a constraint, and minimizing the TMD mass is set as the objective function. The optimal TMD mass that satisfies the comfort constraints is determined, ensuring reduced construction costs and difficulties while meeting the requirements of builders and users alike.