本文選題：無應(yīng)力狀態(tài)控制法 + 幾何非線性��； 參考：《長安大學(xué)》2015年碩士論文

【摘要】：無應(yīng)力狀態(tài)控制法是一種解決分階段施工橋梁結(jié)構(gòu)計(jì)算的理論方法。它在世界上首次建立分階段施工橋梁的力學(xué)平衡方程,第一次從理論上闡明橋梁構(gòu)件單元的無應(yīng)力狀態(tài)量是影響分階段施工橋梁內(nèi)力和線形的本質(zhì)因素,從而可以應(yīng)用構(gòu)件單元的無應(yīng)力狀態(tài)量控制分階段施工橋梁施工過程和成橋狀態(tài)的內(nèi)力、位移。目前無應(yīng)力狀態(tài)控制法已形成一套系統(tǒng)的理論和方法,但是隨著橋梁結(jié)構(gòu)向著超大跨度發(fā)展,特別是斜拉橋,加勁梁一般采用鋼箱梁的結(jié)構(gòu)形式,梁高與跨徑之比進(jìn)一步減小,主梁變得更加纖細(xì),這時(shí)結(jié)構(gòu)體系的幾何非線性問題更加突出地暴露出來。為了能將無應(yīng)力狀態(tài)控制法更好的運(yùn)用在大跨徑斜拉橋施工計(jì)算當(dāng)中,具體的研究內(nèi)容如下:1、無應(yīng)力狀態(tài)法的基本方程。首先基于勢(shì)能駐值原理,推導(dǎo)了考慮幾何非線性的分階段成形結(jié)構(gòu)無應(yīng)力狀態(tài)控制法一般靜力平衡方程。根據(jù)一般靜力平衡方程,分別得出了分階段成形平面桿單元、梁單元結(jié)構(gòu)的無應(yīng)力狀態(tài)控制法靜力平衡方程。最后基于解析解得出了分階段張拉平面索單元的無應(yīng)力狀態(tài)控制法靜力平衡方程,對(duì)其非線性求解問題做了介紹。2、根據(jù)非線性有限元求解理論,分別得到了平面梁單元結(jié)構(gòu)無應(yīng)力狀態(tài)控制法全量列式和增量列式的平衡方程;分別詳細(xì)論述了運(yùn)用TL列式、UL列式、CR-UL列式、CR-TL列式求解平衡方程的過程,并且通過實(shí)例驗(yàn)證了共轉(zhuǎn)坐標(biāo)法求解幾何非線性問題的優(yōu)越性。上述四種列式求解平衡方程的基本思路,對(duì)于桿單元和索單元來說也是適用的。3、通過數(shù)值算例,驗(yàn)證了分階段成形結(jié)構(gòu)無應(yīng)力狀態(tài)控制法靜力平衡方程。分階段成形結(jié)構(gòu)的內(nèi)力和位移與一次成形結(jié)構(gòu)產(chǎn)生差異的本質(zhì)原因不在于結(jié)構(gòu)成形方式不同,而是因?yàn)榉蛛A段成形結(jié)構(gòu)的無應(yīng)力狀態(tài)量與一次成形結(jié)構(gòu)不一致。4、對(duì)無應(yīng)力狀態(tài)控制法在斜拉橋施工仿真計(jì)算中的運(yùn)用進(jìn)行了理論分析,闡述了無應(yīng)力正裝分析的基本原理。以兩個(gè)具體的鋼箱梁斜拉橋工程為例,對(duì)一500m級(jí)斜拉橋,按線性無應(yīng)力正裝計(jì)算的結(jié)果與合理成橋狀態(tài)相同,而且比倒拆-正裝迭代分析方法更簡單。對(duì)一600m級(jí)斜拉橋,分別取兩種不同的成形方式,按非線性無應(yīng)力正裝計(jì)算,兩種成形方式各索一次張拉索力不同,但施工過程索力變化趨勢(shì)大致相同,且成橋階段都收斂于合理成橋索力,且主梁最終狀態(tài)的內(nèi)力和位移計(jì)算結(jié)果都與合理成橋狀態(tài)相差很小,驗(yàn)證了在大跨度斜拉橋施工階段仿真分析中運(yùn)用無應(yīng)力狀態(tài)控制法可靠性,進(jìn)一步驗(yàn)證了無應(yīng)力狀態(tài)控制法的基本方程,為無應(yīng)力正裝計(jì)算的推廣運(yùn)用提供了理論基礎(chǔ)和借鑒。
[Abstract]:The stress-free state control method is a theoretical method to solve the problem of bridge structure calculation. It is the first time in the world to establish the mechanical equilibrium equation of a phased construction bridge. For the first time, it is theoretically stated that the non-stress state of the bridge member element is the essential factor affecting the internal force and the linear shape of the bridge in the phased construction. Thus the non-stress state of the component element can be used to control the internal force and displacement of the construction process and the completed state of the bridge. At present, no stress state control method has formed a set of systematic theories and methods. However, with the development of bridge structure towards large span, especially for cable-stayed bridge, the stiffening beam generally adopts the structural form of steel box girder, and the ratio of beam height to span decreases further. As the main beam becomes more slender, the geometric nonlinearity of the structural system becomes more prominent. In order to apply the stress-free state control method to the construction calculation of long-span cable-stayed bridge, the concrete research contents are as follows: 1, the basic equation of the stress-free state method. Based on the standing principle of potential energy, the general static equilibrium equation of the non-stress state control method for stage-forming structures considering geometric nonlinearity is derived. According to the general static equilibrium equation, the static equilibrium equations of the non-stress state control method for the plane bar element and the beam element structure are obtained respectively. Finally, based on the analytical solution, the static equilibrium equation of the unstressed state control method for the tensioned plane cable element is obtained, and the nonlinear solution problem is introduced. 2. According to the theory of nonlinear finite element solution, In this paper, the equilibrium equations of the total and incremental equations of the stress-free state control method for plane beam element structures are obtained, respectively, and the process of solving the equilibrium equations by using the TL column and CR-UL and CR-TL respectively is discussed in detail. An example is given to verify the superiority of the corotating coordinate method in solving geometric nonlinear problems. The basic idea of solving the equilibrium equation by the above four formulations is also applicable to the bar element and cable element. The static equilibrium equation of the non-stress state control method for the stage-forming structure is verified by numerical examples. The essential reason for the difference between the internal force and displacement of the stage-forming structure and that of the primary forming structure is not the difference in the forming mode of the structure. But because the stress-free state of the stage-forming structure is not consistent with that of the one-stage forming structure, the application of the stress-free state control method in the simulation calculation of cable-stayed bridge construction is theoretically analyzed, and the basic principle of the stress-free dress analysis is expounded. Taking two concrete steel box girder cable-stayed bridges as an example, the calculation results of a 500m class cable-stayed bridge are the same as those of the reasonable bridge state, and are simpler than that of the inverted disassembly and normal load iterative analysis method. For a 600m class cable-stayed bridge, two different forming methods are taken. According to the calculation of nonlinear stress-free formwork, the tension of each cable is different in one time, but the change trend of cable force is roughly the same during construction. The final state of the main beam is calculated by the internal force and displacement, and the difference between the final state of the main beam and the reasonable state of the bridge is very small. The reliability of the stress-free state control method is verified in the simulation analysis of large-span cable-stayed bridge during the construction stage, and the basic equation of the stress-free state control method is further verified, which provides a theoretical basis and a reference for the popularization and application of unstressed dress calculation.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U445.4

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本文編號(hào)：1850669