本文選題：薄壁空心橋墩　切入點(diǎn)：高階振型　出處：《中國(guó)地震局工程力學(xué)研究所》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本文對(duì)高墩大跨剛構(gòu)橋梁的地震損傷機(jī)制進(jìn)行研究,針對(duì)鋼筋混凝土薄壁空心橋墩這種特殊構(gòu)件的破壞機(jī)理進(jìn)行了數(shù)值模擬與試驗(yàn),重點(diǎn)考察了高階振型對(duì)薄壁空心墩力學(xué)性能的影響。為了模擬整橋地震響應(yīng)和損傷發(fā)展轉(zhuǎn)移過程,發(fā)展了可協(xié)調(diào)多種物理域的子結(jié)構(gòu)混合試驗(yàn)系統(tǒng),利用界面單元方法,解決不同子域的邊界協(xié)調(diào)問題。本文主要進(jìn)行了如下的工作:第一,對(duì)薄壁空心橋墩進(jìn)行了數(shù)值模擬,用相關(guān)試驗(yàn)結(jié)果標(biāo)定數(shù)值模型。并進(jìn)行了參數(shù)分析,研究軸壓比與壁厚比對(duì)橋墩的影響,較大的壁厚比與較小的軸壓比是有利的,高軸壓比雖然可以抑制裂縫的發(fā)展,但是易出現(xiàn)脆性破壞。第二,對(duì)整橋進(jìn)行了有限元建模,分析了橋梁的靜力與動(dòng)力響應(yīng),最后提取了子結(jié)構(gòu)邊界處的反力,為試驗(yàn)體加載方案的設(shè)計(jì)提供了依據(jù)。第三,制作了橋墩子結(jié)構(gòu)試驗(yàn)體,在子結(jié)構(gòu)邊界處考慮三個(gè)自由度的協(xié)同加載,其中豎向兩臺(tái)作動(dòng)器為力控制模式,模擬邊界彎矩和軸力,水平方向位移控制;為了模擬分布質(zhì)量,在1層隔板處設(shè)置另一個(gè)水平加載點(diǎn),為力控制加載模式。彎矩、軸力、和水平荷載的比例關(guān)系是按照橋梁的第一振型比例計(jì)算出的。結(jié)果表明橋墩具有良好的延性。與不考慮邊界彎矩的試驗(yàn)結(jié)果相比,歸一化骨架曲線基本一致,說明加載方式對(duì)破壞模式的影響不大,但是本文的加載模式更加接近橋梁的真實(shí)受力狀況。第四,針對(duì)子結(jié)構(gòu)混合試驗(yàn)中不同物理域之間的邊界協(xié)調(diào)問題,提出了界面單元的方法,利用約束變分原理進(jìn)行了相關(guān)推導(dǎo),并利用算例驗(yàn)證此種方法的精確性。第五,為在子結(jié)構(gòu)混合試驗(yàn)中使用界面單元,引入靜力凝聚與BFGS方法,這樣只需要提取邊界上的力與位移即可實(shí)現(xiàn)多子域不共節(jié)點(diǎn)的界面協(xié)調(diào)。
[Abstract]:In this paper, the seismic damage mechanism of long-span rigid frame bridges with high piers is studied, and the failure mechanism of the special members such as reinforced concrete thin-walled hollow piers is numerically simulated and tested. The influence of high-order modes on the mechanical properties of thin-walled hollow piers is emphatically investigated. In order to simulate the seismic response and damage development transfer process of the whole bridge, a hybrid test system for substructures, which can coordinate various physical domains, is developed, and the interface element method is used. The main work of this paper is as follows: first, numerical simulation of thin-walled hollow bridge pier is carried out, and the numerical model is calibrated with relevant experimental results. The influence of axial compression ratio to wall thickness ratio on bridge piers is studied. The larger wall thickness ratio and the smaller axial pressure ratio are advantageous. Although high axial compression ratio can restrain the development of cracks, it is prone to brittle failure. Secondly, the finite element method is used to model the whole bridge. The static and dynamic responses of the bridge are analyzed. At last, the reaction force at the boundary of the substructure is extracted, which provides the basis for the design of the loading scheme of the test body. Thirdly, the test body of the substructure of the pier is made. Three degrees of freedom co-loading are considered at the boundary of the substructure, in which two vertical actuators are force control mode to simulate boundary moment and axial force, horizontal displacement control, in order to simulate the distributed mass. Set another horizontal loading point at the 1st floor partition to control loading mode for force. Moment, axial force, The results show that the pier has good ductility. Compared with the experimental results without considering the boundary moment, the normalized skeleton curve is basically consistent. It is shown that the loading mode has little effect on the failure mode, but the loading mode in this paper is closer to the real stress condition of the bridge. 4th, aiming at the boundary coordination problem between different physical domains in the substructure mixed test, In this paper, a method of interface element is proposed, and the correlation derivation is carried out by using the constrained variational principle. The accuracy of this method is verified by an example. 5th. In order to use the interface element in the substructure mixing test, the static coacervation and BFGS method are introduced. In this way, only the forces and displacements on the boundary can be extracted to achieve the interface coordination of multi-subdomain non-common nodes.
【學(xué)位授予單位】：中國(guó)地震局工程力學(xué)研究所
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U442.55

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相關(guān)期刊論文 前1條

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本文編號(hào)：1587733