【摘要】：本文以鎮(zhèn)江某大跨越塔-線體系為背景工程,輸電塔高度為198m,跨越距離約1200m。輸電塔所處環(huán)境較為復(fù)雜,受到荷載主要有風(fēng)荷載、重力荷載、地震荷載、覆冰荷載等,針對輸電塔等高聳結(jié)構(gòu)而言,對結(jié)構(gòu)穩(wěn)定產(chǎn)生影響的因素主要是由風(fēng)荷載作用。本文在已有成果的基礎(chǔ)上對跨越塔的風(fēng)荷載響應(yīng)進(jìn)一步進(jìn)行非線性分析研究,針對背景工程進(jìn)行了輸電塔對比選型,利用大型有限元分析軟件ANSYS對塔及塔-線體系建模,進(jìn)行考慮P-△效應(yīng)的情況下輸電塔和塔-線體系的動力特性分析及在動力特性分析的基礎(chǔ)上利用現(xiàn)有理論的等效靜力法分析輸電塔的風(fēng)荷載響應(yīng),按照彈性屈曲失穩(wěn)模式的分析方法對塔體的使用階段進(jìn)行分析獲得彈性屈曲的安全系數(shù)及結(jié)構(gòu)屈曲模態(tài)和失穩(wěn)構(gòu)件的破壞形式,建立結(jié)構(gòu)的非線性分析模型分析研究鐵塔及塔-線體系極限承載力。單塔模型模態(tài)分析結(jié)果顯示結(jié)構(gòu)的第一階振型為橫向振動即為結(jié)構(gòu)體系最容易發(fā)生失穩(wěn)時荷載方向,利用施加風(fēng)荷載進(jìn)行彈性屈曲分析的結(jié)果同時引入結(jié)構(gòu)3‰的初始缺陷、材料的非線性本構(gòu)模型進(jìn)行考慮大變形的非線性屈曲分析。結(jié)果顯示在結(jié)構(gòu)屈曲以鐵塔根部主材最先達(dá)到材料的屈服應(yīng)力開始,通過跟蹤結(jié)構(gòu)最高點(diǎn)的荷載-位移關(guān)系,在風(fēng)速達(dá)到68m/s時結(jié)構(gòu)整體失穩(wěn),在考慮風(fēng)速脈動的情況下,結(jié)構(gòu)的極限承載力降低。通過導(dǎo)線應(yīng)力控制對塔-線體系進(jìn)行找形然后進(jìn)行動力特性和考慮結(jié)構(gòu)二階效應(yīng)的屈曲分析,由于導(dǎo)線屬于柔性結(jié)構(gòu)其存在對體系中其他部分產(chǎn)生耦合作用影響,結(jié)構(gòu)體系的振動周期相對單塔增加約27.6%、體系的極限承載力相對單塔降低至48m/s。
[Abstract]:Based on a large span tower-line system in Zhenjiang, the transmission tower height is 198 m and the span distance is about 1 200 m. The transmission tower is located in a complex environment, which is mainly subjected to wind load, gravity load, earthquake load, ice load and so on. For tall structures such as transmission towers, the main factors that affect the stability of the structure are wind loads. In this paper, based on the existing achievements, the nonlinear analysis of the wind load response of the span tower is carried out, and the comparison and selection of the transmission tower for the background engineering are carried out, and the tower and the tower-line system are modeled by using the large-scale finite element analysis software ANSYS. The dynamic characteristics of transmission tower and tower-line system are analyzed under the consideration of P- effect, and the wind load response of transmission tower is analyzed by using the equivalent static method of existing theory on the basis of dynamic characteristic analysis. According to the analysis method of elastic buckling failure mode, the safety factor of elastic buckling, the buckling mode of structure and the failure mode of unstable members are obtained by analyzing the use stage of tower body. The nonlinear analysis model is established to analyze the ultimate bearing capacity of tower and tower-line system. The results of modal analysis of single tower model show that the first vibration mode of the structure is transverse vibration, that is, the direction of load when the structure system is most vulnerable to instability. The results of elastic buckling analysis under wind load are used to introduce the initial defect of the structure of 3 鈥，

本文編號：2200469