拱壩結(jié)構(gòu)設(shè)計應(yīng)力控制標(biāo)準(zhǔn)研究
發(fā)布時間：2018-10-05 19:42
【摘要】：拱壩結(jié)構(gòu)設(shè)計應(yīng)力控制標(biāo)準(zhǔn)的研究是拱壩設(shè)計領(lǐng)域一個復(fù)雜而又重要的課題,應(yīng)力控制標(biāo)準(zhǔn)的合理性將直接關(guān)系著拱壩的經(jīng)濟(jì)性和安全性。當(dāng)前,在拱壩結(jié)構(gòu)設(shè)計中主要的應(yīng)力分析方法有拱梁分載法和有限單元法。相對于拱梁分載法,有限單元法擁有較強(qiáng)的適用性,能夠解決許多拱梁分載法不能解決的復(fù)雜問題。但其計算結(jié)果受計算網(wǎng)格影響較大,同時在建基面附近易出現(xiàn)應(yīng)力集中,給有限元應(yīng)力控制標(biāo)準(zhǔn)的制定帶來困難。為解決上述提到的問題,現(xiàn)行拱壩設(shè)計規(guī)范采用的方法是有限元等效應(yīng)力法,并制定了相應(yīng)的應(yīng)力設(shè)計標(biāo)準(zhǔn)。但有限元等效應(yīng)力法中關(guān)于應(yīng)力分量的線性化假定與拱壩真實(shí)的應(yīng)力分布規(guī)律不相符合。本文在分析拱、梁向應(yīng)力分布規(guī)律的基礎(chǔ)上,提出了拱壩有限元三次等效應(yīng)力法。并依托小灣、二灘、楊房溝、周公宅四座拱壩工程,開展三次等效應(yīng)力控制標(biāo)準(zhǔn)的研究,并給出相應(yīng)的應(yīng)力控制指標(biāo)的建議值。主要研究內(nèi)容如下:(1)總結(jié)了關(guān)于國內(nèi)外拱壩主要的應(yīng)力分析方法及其相應(yīng)的應(yīng)力控制標(biāo)準(zhǔn)的基本內(nèi)容和進(jìn)展,分析比較不同應(yīng)力分析的優(yōu)缺點(diǎn)及其應(yīng)力控制指標(biāo)的制定方式,為三次等效應(yīng)力法的應(yīng)力控制指標(biāo)的提出作鋪墊。(2)介紹了拱壩有限元分析的基本理論,著重講述了有限元分析過程。在此基礎(chǔ)上,簡要概況了 ANSYS的有限元求解。(3)分析了拱壩梁、拱應(yīng)力分布規(guī)律,基于最小二乘法擬合多項(xiàng)式提出拱壩有限元三次等效應(yīng)力分析方法及其計算步驟。結(jié)合小灣拱壩工程,研究了三次等效應(yīng)力對有限元模型網(wǎng)格的敏感性,結(jié)果顯示三次等效應(yīng)力法可消除網(wǎng)格效應(yīng)影響。(4)利用ANSYS軟件對四座拱壩建立有限元分析模型并進(jìn)行基本荷載組合下的三維線彈性有限元分析,并分別計算了有限元三次等效應(yīng)力和設(shè)計規(guī)范中的有限元等效應(yīng)力。通過分析對比兩種等效應(yīng)力的最大拉壓應(yīng)力,提出了有限元三次等效應(yīng)力設(shè)計標(biāo)準(zhǔn)的確定方法,并結(jié)合DL/T5346-2006規(guī)范和SL282-2003規(guī)范給出了相應(yīng)的控制指標(biāo)。
[Abstract]:The research of stress control standard for arch dam structure design is a complex and important subject in the field of arch dam design. The rationality of stress control standard will directly affect the economy and safety of arch dam. At present, the main stress analysis methods in arch dam structure design include arch beam load sharing method and finite element method. Compared with the arch beam load sharing method, the finite element method has a strong applicability and can solve many complex problems which can not be solved by the arch beam load separation method. However, the calculation results are greatly affected by the calculation grid, and stress concentration is easy to occur near the foundation plane, which makes it difficult to formulate the finite element stress control standard. In order to solve the problems mentioned above, the current design code for arch dams adopts the method of finite element equal effect force method, and formulates the corresponding stress design standard. But the linearization assumption of the stress component in the finite element equal effect force method does not accord with the true stress distribution of the arch dam. Based on the analysis of the stress distribution of arch and beam, the third order effect force method of arch dam is presented in this paper. Based on the four arch dams of Xiaowan, Ertan, Yangfanggou and Zhougongzhai, the research on three equivalent stress control standards is carried out, and the corresponding suggested stress control index is given. The main research contents are as follows: (1) the main stress analysis methods and their corresponding stress control standards at home and abroad are summarized, and the advantages and disadvantages of different stress analysis and the formulation of stress control indexes are analyzed and compared. The basic theory of finite element analysis of arch dam is introduced, and the process of finite element analysis is emphasized. On this basis, the finite element solution of ANSYS is briefly introduced. (3) the stress distribution of arch dam beam and arch is analyzed. Based on the least square fitting polynomial, the cubic equivalent stress analysis method of arch dam and its calculation steps are proposed. Combined with Xiaowan arch dam project, the sensitivity of cubic equivalent stress to finite element model mesh is studied. The results show that the third order effect force method can eliminate the influence of grid effect. (4) the finite element analysis model of four arch dams is established by using ANSYS software and the three-dimensional linear elastic finite element analysis under the basic load combination is carried out. The cubic equivalent stress of the finite element and the equivalent stress of the finite element in the design code are calculated respectively. By analyzing and comparing the maximum tensile and compressive stresses of two kinds of equivalent stresses, a method of determining the design standard of the cubic equivalent stress of finite element is put forward, and the corresponding control indexes are given in combination with the DL/T5346-2006 Code and the SL282-2003 Code.
【學(xué)位授予單位】：揚(yáng)州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TV642.4;TV31
，
本文編號：2254633
[Abstract]:The research of stress control standard for arch dam structure design is a complex and important subject in the field of arch dam design. The rationality of stress control standard will directly affect the economy and safety of arch dam. At present, the main stress analysis methods in arch dam structure design include arch beam load sharing method and finite element method. Compared with the arch beam load sharing method, the finite element method has a strong applicability and can solve many complex problems which can not be solved by the arch beam load separation method. However, the calculation results are greatly affected by the calculation grid, and stress concentration is easy to occur near the foundation plane, which makes it difficult to formulate the finite element stress control standard. In order to solve the problems mentioned above, the current design code for arch dams adopts the method of finite element equal effect force method, and formulates the corresponding stress design standard. But the linearization assumption of the stress component in the finite element equal effect force method does not accord with the true stress distribution of the arch dam. Based on the analysis of the stress distribution of arch and beam, the third order effect force method of arch dam is presented in this paper. Based on the four arch dams of Xiaowan, Ertan, Yangfanggou and Zhougongzhai, the research on three equivalent stress control standards is carried out, and the corresponding suggested stress control index is given. The main research contents are as follows: (1) the main stress analysis methods and their corresponding stress control standards at home and abroad are summarized, and the advantages and disadvantages of different stress analysis and the formulation of stress control indexes are analyzed and compared. The basic theory of finite element analysis of arch dam is introduced, and the process of finite element analysis is emphasized. On this basis, the finite element solution of ANSYS is briefly introduced. (3) the stress distribution of arch dam beam and arch is analyzed. Based on the least square fitting polynomial, the cubic equivalent stress analysis method of arch dam and its calculation steps are proposed. Combined with Xiaowan arch dam project, the sensitivity of cubic equivalent stress to finite element model mesh is studied. The results show that the third order effect force method can eliminate the influence of grid effect. (4) the finite element analysis model of four arch dams is established by using ANSYS software and the three-dimensional linear elastic finite element analysis under the basic load combination is carried out. The cubic equivalent stress of the finite element and the equivalent stress of the finite element in the design code are calculated respectively. By analyzing and comparing the maximum tensile and compressive stresses of two kinds of equivalent stresses, a method of determining the design standard of the cubic equivalent stress of finite element is put forward, and the corresponding control indexes are given in combination with the DL/T5346-2006 Code and the SL282-2003 Code.
【學(xué)位授予單位】：揚(yáng)州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TV642.4;TV31
，
本文編號：2254633
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