【摘要】：結(jié)構(gòu)的優(yōu)化設(shè)計(jì)不只是追求結(jié)構(gòu)的重量最小或者是造價(jià)最低，更重要的是要保證結(jié)構(gòu)優(yōu)化后的安全性。對(duì)桁架這類具有明顯失效歷程的結(jié)構(gòu)優(yōu)化設(shè)計(jì)，需要考慮結(jié)構(gòu)的體系可靠性。本文探討了結(jié)構(gòu)構(gòu)件及體系可靠性分析方法，提出了適用于工程結(jié)構(gòu)的體系可靠性優(yōu)化方法，最后對(duì)標(biāo)準(zhǔn)十桿平面桁架和鋼桁梁結(jié)構(gòu)進(jìn)行了體系可靠性優(yōu)化分析。具體研究?jī)?nèi)容如下： (1)探討了結(jié)構(gòu)構(gòu)件可靠度和結(jié)構(gòu)體系可靠度的分析方法，并對(duì)各種方法的適用范圍和優(yōu)缺點(diǎn)進(jìn)行說明。在JC法、MC法和窄界限法的理論基礎(chǔ)上，在MATLAB平臺(tái)上編制了可靠度計(jì)算軟件。為結(jié)構(gòu)體系可靠性優(yōu)化設(shè)計(jì)中體系可靠性求解問題打下基礎(chǔ)。 (2)提出基于遺傳算法和神經(jīng)網(wǎng)絡(luò)的結(jié)構(gòu)體系可靠性優(yōu)化設(shè)計(jì)方法。該方法首先由BP神經(jīng)網(wǎng)絡(luò)映射出隨機(jī)變量與結(jié)構(gòu)受力關(guān)系，采用Monte Carlo Method得出各失效模式的可靠指標(biāo)；然后由β約界法得出結(jié)構(gòu)失效樹，采用PNET(概率網(wǎng)絡(luò)估算技術(shù))法計(jì)算體系可靠指標(biāo)；最后以選取的目標(biāo)體系可靠指標(biāo)為約束條件，以罰函數(shù)的方式引入遺傳算法，在MATLAB平臺(tái)實(shí)現(xiàn)優(yōu)化設(shè)計(jì)。 (3)通過十桿平面桁架和鋼桁梁的算例分析，表明該方法可適用于此類結(jié)構(gòu)的優(yōu)化設(shè)計(jì)。參數(shù)分析表明：傳統(tǒng)確定性優(yōu)化和構(gòu)件層次可靠性優(yōu)化不能保證上述結(jié)構(gòu)的體系可靠性，隨著目標(biāo)體系可靠指標(biāo)和變異系數(shù)的增大，其對(duì)優(yōu)化結(jié)果影響越大。 (4)建立了鋼桁梁結(jié)構(gòu)體系可靠性優(yōu)化數(shù)學(xué)模型，對(duì)某懸索橋的桁架式主梁結(jié)構(gòu)進(jìn)行了體系可靠性優(yōu)化分析。分析結(jié)果表明：該結(jié)構(gòu)的最初失效狀態(tài)表現(xiàn)為腹桿的壓應(yīng)力屈曲失效，最終失效狀態(tài)表現(xiàn)為縱、橫梁跨中彎曲失效。適當(dāng)減小某鋼桁梁結(jié)構(gòu)的縱、橫梁截面面積和增加腹桿面積，可在保證體系可靠度的情況下減小結(jié)構(gòu)重量，也可在結(jié)構(gòu)重量不變的情況下提高結(jié)構(gòu)體系可靠指標(biāo)。
[Abstract]:The optimal design of the structure is not only to seek the minimum weight or the lowest cost of the structure, but also to ensure the safety of the optimized structure. The structural reliability should be considered in the optimal design of truss with obvious failure history. In this paper, the reliability analysis method of structural members and systems is discussed, and the system reliability optimization method suitable for engineering structures is put forward. Finally, the system reliability optimization analysis of standard ten-bar plane truss and steel truss structure is carried out. The main contents of this paper are as follows: (1) the reliability analysis methods of structural components and structural systems are discussed, and the applicability, advantages and disadvantages of these methods are explained. Based on the theory of JC method, MC method and narrow bound method, the reliability calculation software is developed on MATLAB platform. It lays a foundation for the system reliability solution in the structural system reliability optimization design. (2) A reliability optimization design method based on genetic algorithm and neural network is proposed. Firstly, the BP neural network is used to map out the relationship between random variables and structural forces, and the reliability index of each failure mode is obtained by Monte Carlo Method. Then the structure failure tree is obtained by 尾 -reduction method, and the reliability index of the system is calculated by PNET (probabilistic network estimation technique). Finally, taking the selected reliability index of the target system as the constraint condition, the genetic algorithm is introduced in the form of penalty function, and the optimal design is realized on the MATLAB platform. (3) through the example analysis of ten bar plane truss and steel truss, it is shown that this method can be applied to the optimization design of this kind of structure. The parameter analysis shows that traditional deterministic optimization and component hierarchical reliability optimization can not guarantee the reliability of these structures. With the increase of reliability index and coefficient of variation of the target system, the greater the impact on the optimization results. (4) the reliability optimization mathematical model of steel truss beam structure is established, and the system reliability optimization analysis of the truss girder structure of a suspension bridge is carried out. The results show that the initial failure state of the structure is the buckling failure of the compressive stress of the web bar, and the ultimate failure state is the longitudinal failure and the mid-span bending failure of the beam. Reducing the cross section area of a steel truss beam and increasing the area of web bar can reduce the weight of the structure under the condition of ensuring the reliability of the system, but also improve the reliability index of the structure system when the weight of the structure remains unchanged.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TU318

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 蔣友寶;馮健;孟少平;;基于狀態(tài)空間響應(yīng)面方法的結(jié)構(gòu)系統(tǒng)可靠度分析[J];工程力學(xué);2007年01期

2 黃冀卓;王湛;;基于遺傳算法的離散型結(jié)構(gòu)拓?fù)鋬?yōu)化設(shè)計(jì)[J];工程力學(xué);2008年05期

3 劉揚(yáng);魯乃唯;;鋼管混凝土組合高墩連續(xù)剛構(gòu)橋體系可靠指標(biāo)計(jì)算方法[J];公路交通科技;2011年09期

4 蔡新;李洪煊;武穎利;朱杰;;工程結(jié)構(gòu)優(yōu)化設(shè)計(jì)研究進(jìn)展[J];河海大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年03期

5 馮元生,董聰;枚舉結(jié)構(gòu)主要失效模式的一種方法[J];航空學(xué)報(bào);1991年09期

6 許素強(qiáng),夏人偉;結(jié)構(gòu)優(yōu)化方法研究綜述[J];航空學(xué)報(bào);1995年04期

7 顧祥林;陳少杰;張偉平;;既有建筑結(jié)構(gòu)體系可靠性評(píng)估實(shí)用方法[J];結(jié)構(gòu)工程師;2007年04期

8 張義民,張雷;結(jié)構(gòu)系統(tǒng)可靠性優(yōu)化設(shè)計(jì)的神經(jīng)網(wǎng)絡(luò)方法[J];計(jì)算力學(xué)學(xué)報(bào);2005年03期

9 程耿東;許林;;基于可靠度的結(jié)構(gòu)優(yōu)化的序列近似規(guī)劃算法[J];計(jì)算力學(xué)學(xué)報(bào);2006年06期

10 王曉軍;楊海峰;邱志平;覃梓軒;;基于非概率集合可靠性的結(jié)構(gòu)優(yōu)化設(shè)計(jì)[J];計(jì)算力學(xué)學(xué)報(bào);2011年06期

相關(guān)博士學(xué)位論文 前2條

1 張小慶;結(jié)構(gòu)體系可靠度分析方法研究[D];大連理工大學(xué);2003年

2 何嘉年;基于體系可靠度的半剛性鋼框架結(jié)構(gòu)優(yōu)化設(shè)計(jì)研究[D];汕頭大學(xué);2010年

相關(guān)碩士學(xué)位論文 前2條

1 商懷帥;桁架結(jié)構(gòu)的可靠度分析與優(yōu)化設(shè)計(jì)[D];大連理工大學(xué);2006年

2 李靖;基于體系可靠度的平面鋼框架優(yōu)化設(shè)計(jì)[D];湖南大學(xué);2008年

，

本文編號(hào)：2428085