預加力作用下PC箱梁橋局段應力分析
發(fā)布時間：2019-05-03 20:32
【摘要】：隨著箱梁寬度的逐漸增大,采用懸臂施工的連續(xù)梁及連續(xù)剛構(gòu)橋,在施工的前數(shù)個階段中,即施工短懸臂狀態(tài),采用梁單元理論進行施工階段驗算結(jié)構(gòu)響應的不適用性,逐漸引起橋梁界的關(guān)注。在短懸臂狀態(tài),采用梁單元理論得到的應力與結(jié)構(gòu)實際應力分布的差別,如何正確模擬后張法預應力鋼筋等問題,亟待形成系統(tǒng)的研究成果。因此,本文以短懸臂狀態(tài)下橋梁在預應力荷載作用下的局部應力為研究對象,進行了較為深入的研究,希望進一步完善PC箱梁橋的設計理論和方法,同時為施工提供一定的借鑒和參考。本文對PC箱梁橋的設計和分析理論進行了系統(tǒng)的論述、對比與總結(jié),研究表明在施工的短懸臂狀態(tài)采用梁單元進行分析是不精確的,亦或是造成橋梁在后期運營過程中開裂的隱患�；趯嶓w有限元數(shù)值模擬法來實現(xiàn)后張法預應力作用下PC箱梁橋局段應力分析的方法,本文以花卉大橋為背景對不同建模方式的要點進行了明確的闡述,可為工程建造提供指導性意見。通過采用兩種不同的方式進行預應力鋼筋與混凝土單元的節(jié)點耦合建立的AN SYS實體有限元分析模型與基于初等梁單元的M idas-civil模型數(shù)據(jù)對比,結(jié)果表明采用初等梁單元進行分析不能夠準確反映截面應力的分布,由于截面寬度較大,同一截面高度上應力分布是不均勻的。為進一步修正初等梁單元模型的誤差,采用有效翼板寬度理論進行修正。結(jié)果表明,此理論還是不能用來計算結(jié)構(gòu)的應力水平,腹板縱向正應力與實體單元分析的應力吻合較好。為進一步驗證實體有限元數(shù)據(jù)的可信度,與花卉大橋?qū)崢虻谋O(jiān)控數(shù)據(jù)進行了對比。研究表明,采用半耦合方式建立實體單元的有限元模擬更能夠準確模擬結(jié)構(gòu)的應力分布。研究表明采用梁單元理論分析橋梁在預應力荷載作用下的局部應力引起的誤差,應該引起足夠的重視。
[Abstract]:As the width of box girder increases gradually, the continuous beam and continuous rigid frame bridge constructed by cantilever, in the first few stages of construction, namely, the short cantilever state of construction, adopts the beam element theory to check the inapplicability of structural response in the construction stage. Gradually aroused the attention of bridge boundaries. In the short cantilever state, the difference between the stress obtained by the beam element theory and the actual stress distribution of the structure, how to correctly simulate the pre-stressed steel bars after Zhang Fa, and so on, need to form systematic research results. Therefore, this paper takes the local stress of the bridge under the prestressing force as the research object under the condition of short cantilever, carries on the more in-depth research, hopes to further perfect the design theory and the method of the PC box girder bridge, At the same time, it provides certain reference and reference for construction. In this paper, the design and analysis theory of PC box girder bridge are systematically discussed, compared and summarized. The research shows that it is imprecise to use beam element to analyze the short cantilever state in construction. Or cause the bridge in the later stage of operation in the process of cracking hidden dangers. Based on the solid finite element numerical simulation method, the stress analysis method of the local section of PC box girder bridge under the action of post-Zhang Fa prestressing force is realized. In this paper, the main points of different modeling methods are clearly expounded on the background of the Flower Bridge. Can provide guidance for the construction of the project. The finite element analysis model of AN SYS entity based on the coupling of prestressed steel bar and concrete element is compared with M-idas-civil model based on elementary beam element in two different ways. The results show that the stress distribution of the cross-section can not be accurately reflected by the elementary beam element analysis. Because of the large width of the cross-section, the stress distribution at the same section height is not uniform. In order to further correct the error of the elementary beam element model, the effective fender width theory is used to correct the error. The results show that this theory can not be used to calculate the stress level of the structure, and the longitudinal normal stress of the web is in good agreement with that of the solid element analysis. In order to verify the reliability of the entity finite element data, the comparison is made with the monitoring data of the real bridge of the Flower Bridge. The results show that the finite element simulation using semi-coupled method can simulate the stress distribution of the structure more accurately. The results show that the error caused by the local stress of bridge under prestressed load should be analyzed by beam element theory, which should be paid more attention to.
【學位授予單位】：湖南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U441;U448.213
本文編號：2469250
[Abstract]:As the width of box girder increases gradually, the continuous beam and continuous rigid frame bridge constructed by cantilever, in the first few stages of construction, namely, the short cantilever state of construction, adopts the beam element theory to check the inapplicability of structural response in the construction stage. Gradually aroused the attention of bridge boundaries. In the short cantilever state, the difference between the stress obtained by the beam element theory and the actual stress distribution of the structure, how to correctly simulate the pre-stressed steel bars after Zhang Fa, and so on, need to form systematic research results. Therefore, this paper takes the local stress of the bridge under the prestressing force as the research object under the condition of short cantilever, carries on the more in-depth research, hopes to further perfect the design theory and the method of the PC box girder bridge, At the same time, it provides certain reference and reference for construction. In this paper, the design and analysis theory of PC box girder bridge are systematically discussed, compared and summarized. The research shows that it is imprecise to use beam element to analyze the short cantilever state in construction. Or cause the bridge in the later stage of operation in the process of cracking hidden dangers. Based on the solid finite element numerical simulation method, the stress analysis method of the local section of PC box girder bridge under the action of post-Zhang Fa prestressing force is realized. In this paper, the main points of different modeling methods are clearly expounded on the background of the Flower Bridge. Can provide guidance for the construction of the project. The finite element analysis model of AN SYS entity based on the coupling of prestressed steel bar and concrete element is compared with M-idas-civil model based on elementary beam element in two different ways. The results show that the stress distribution of the cross-section can not be accurately reflected by the elementary beam element analysis. Because of the large width of the cross-section, the stress distribution at the same section height is not uniform. In order to further correct the error of the elementary beam element model, the effective fender width theory is used to correct the error. The results show that this theory can not be used to calculate the stress level of the structure, and the longitudinal normal stress of the web is in good agreement with that of the solid element analysis. In order to verify the reliability of the entity finite element data, the comparison is made with the monitoring data of the real bridge of the Flower Bridge. The results show that the finite element simulation using semi-coupled method can simulate the stress distribution of the structure more accurately. The results show that the error caused by the local stress of bridge under prestressed load should be analyzed by beam element theory, which should be paid more attention to.
【學位授予單位】：湖南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U441;U448.213
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相關(guān)期刊論文 前2條
1 劉毅;李愛群;丁幼亮;趙大亮;;潤揚懸索橋扁平鋼箱梁局部應力的測試與分析[J];東南大學學報(自然科學版);2007年02期
2 付永強;張小水;胡成;;預應力混凝土結(jié)構(gòu)施加預應力的Ansys模擬[J];工程與建設;2008年06期
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