玻璃纖維橋面板與鋼梁接合行為研究

Abstract

本研究主要探討玻璃纖維橋面板與鋼梁接合時的剪力連接器極限強度與有限元素分析，其中共進行六組單向加載試驗，試體均由一支鋼梁以及兩片橋面板組合而成。實驗結果顯示，破壞模式同樣是剪力釘破壞，在玻璃纖維橋面板下剪力釘的極限抗剪強度確比AASHTO規範(2004)中剪力釘控制的AsFu還低10 %左右，其原因根據試驗觀察有兩個，分別是灌漿單元的水泥砂漿開裂以及墊層的水泥砂漿被擠出所造成。而不同剪力釘直徑也會影響到剪力釘極限抗剪強度，剪力釘直徑越大則強度越高。不同剪力釘支數則不會對剪力釘極限抗剪強度造成影響。本研究並利用有限元素分析程式ABAQUS(2003)，模擬試體行為，首先進行簡化模型的分析，結果顯示水泥砂漿試體的分析結果與試驗結果十分吻合，但玻璃纖維試體由於在試驗中出現水泥砂漿開裂，而水泥砂漿開裂行為在ABAQUS程式中較難模擬，所以分析中極限抗剪強度比起試驗結果約有15 %誤差。接著進行整體模型的分析，整體模型與簡化模型的分析結果十分接近，代表可以用簡化模型代替整體模型的分析，以節省分析時間。根據本研究的結果可知，依照本研究試體的設計，玻璃纖維橋面板在開洞時，開洞的大小為四倍剪力釘直徑，可以有效保護玻璃纖維橋面板不被壓壞。而剪力釘間距參考EUROCODE-4(1997)中建議的100 mm，可以確保剪力釘抗剪強度不受每一排剪力釘支數影響。

This research presents the results of component tests and finite element analysis on the ultimate shear capacity of shear stud under the composite deck. All specimens were composed by a steel beam and two decks and connected with steel beam and deck by shear connectors. There were six push-out test specimens were experimented. From the results, it showed the failure modes of all specimens were caused by shear failure since the stud ultimate shear capacity under FRP deck lower 10 % than the AASHTO specifications (2004) stud control part AsFu. According to the experimental report, there were two obvious reasons; the mainly one was because of the mortar cell’s cracking and the other is due to bedding layer cracking. Using a larger stud diameter would have a larger ultimate shear capacity. However, using one or two studs in one row did not make any difference between stud ultimate shear capacities. Furthermore, this experiment was analysis via ABAQUS(2003).Firstly, the result of the simplified model completely met every condition of the analysis of cement mortar specimen; however we met a difficulty of the composite specimens owing to the cracking during experiment on ABAQUS. There is around 15 % error between the analysis and the test results. Followed, the analysis was examined by the full scale model; it reported the same between simplified model and full scale model. It means that the full scale model could be totally replaced by the simplified model in order to saving time. According to both the original design and results of this study, FRP deck in the open hole which is four times stud diameters could effectively protect the FRP deck by not being crushed. Moreover, this study recommended 100 mm of the shear stud spacing referred from EUROCODE-4(1997) to make sure that the shear capacity would not be affected the stud number in one row.