考虑混凝土材料变异性的超大型冷却塔随机屈曲承载力分析
|
摘要
基于屈曲本征方程的形式解推导出随机屈曲本征值满足的概率密度演化方程。取混凝土弹性模量服从正态分布及对数正态分布,分析了超大型冷却塔随机屈曲承载力的概率密度函数、均值、标准差及可靠度。结果表明:正态分布假定时随机屈曲承载力的均值与不考虑随机性的屈曲承载力十分接近,其变异性与混凝土弹性模量的变异性相似。而对数正态分布假定时,一阶屈曲本征值偏离了正态分布,均值及变异性增大,但可靠度降低。规范关于冷却塔整体稳定安全系数的规定偏于保守。
Based on the formal solutions of the buckling eigen equation,the probability density evolution equation for the random buckling eigenvalue is derived.By assuming that the elastic modulus of concrete follows normal and logarithm normal distributions respectively,the probability density function(PDF),mean,standard deviation and reliability of the buckling bearing capacity for a super-large cooling tower are analyzed.The results indicate that the mean buckling bearing capacity based on normal assumption is very close to the one with the deterministic parameter,and its variation is the same as the elastic modulus of concrete.For the logarithm normal assumption,however,the PDF of buckling bearing capacity deviates normal distribution,while the corresponding mean and variation increase but the reliability decreases.The safety factor for the overall buckling of cooling towers required in the design standard is relatively conservative.
Based on the formal solutions of the buckling eigen equation,the probability density evolution equation for the random buckling eigenvalue is derived.By assuming that the elastic modulus of concrete follows normal and logarithm normal distributions respectively,the probability density function(PDF),mean,standard deviation and reliability of the buckling bearing capacity for a super-large cooling tower are analyzed.The results indicate that the mean buckling bearing capacity based on normal assumption is very close to the one with the deterministic parameter,and its variation is the same as the elastic modulus of concrete.For the logarithm normal assumption,however,the PDF of buckling bearing capacity deviates normal distribution,while the corresponding mean and variation increase but the reliability decreases.The safety factor for the overall buckling of cooling towers required in the design standard is relatively conservative.
引文
[1]Busch D,Harte R,Niemann H.Study of a proposed200m high natural draught cooling tower at power plantFrimmersdorf,Germany[J].Engineering Structures,1998,20(10):920―927.
[2]DL/T5339-2006,火力发电厂水工设计规范[S].北京:中国电力出版社,2006.DL/T 5339-2006,Code for hydraulic design of fossil fuelpower plants[S].Beijing:China Electric Power Press,2006.(in Chinese)
[3]Liao W,Lu W D,Liu R H.Effect of soil-structureinteraction on the reliability of hyperbolic cooling towers[J].Structural Engineering and Mechanics,1999,7(2):217―224.
[4]Choi C K,Noh H C.Stochastic analysis of shapeimperfection in RC cooling tower shells[J].Journal ofStructural Engineering,2000,126(3):417―423.
[5]廖汶,卢文达,刘人怀.双曲冷却塔结构非线性有限元可靠度分析[J].工程力学,1999,16(1):49―55.Liao Wen,Lu Wenda,Liu Renhuai.Finite elementreliability analysis of hyperbolic cooling towers[J].Engineering Mechanics,1999,16(1):49―55.(inChinese)
[6]许林汕,赵林,葛耀君.超大型冷却塔随机风振响应分析[J].振动与冲击,2009,28(4):180―184.Xu Linshan,Zhao Lin,Ge Yaojun.Wind-excitedstochastic responses of super large cooling towers[J].Journal of Vibration and Shock,2009,28(4):180―184.(in Chinese)
[7]陈铁云,沈惠申.结构的屈曲[M].上海:上海科学技术出版社,1993:15―16.Chen Tieyun,Shen Huishen.Structural buckling[M].Shanghai:Shanghai Scientific and TechnologicalLiterature Press,1993:15―16.(in Chinese)
[8]李杰,陈建兵.随机结构非线性动力反应的概率密度演化分析[J].力学学报,2003,35(6):716―722.Li Jie,Chen Jianbing.The probability density evolutionmethod for analysis of dynamic nonlinear response ofstochastic structures[J].Acta Mechanica Sinica,2003,35(6):716―722.(in Chinese)
[9]陈建兵,李杰.非线性随机结构动力可靠度的密度演化方法[J].力学学报,2004,36(2):196―201.Chen Jianbing,Li Jie.The probability density evolutionmethod for dynamic reliability assessment of nonlinearstochastic structures[J].Acta Mechanica Sinica,2004,36(2):196―201.(in Chinese)
[10]Li J,Chen J B.The principle of preservation ofprobability and the generalized density evolutionequation[J].Structural Safety,2008,30:65―77.
[11]陈建兵,李杰.随机结构动力可靠度分析的极值概率密度方法[J].地震工程与工程振动,2004,24(6):39―44.Chen Jianbing,Li Jie.The extreme value probabilitydensity function based method for dynamic reliabilityassessment of stochastic structures[J].EarthquakeEngineering and Engineering Vibration,2004,24(6):39―44.(in Chinese)
[12]Li J,Chen J B.The probability density evolution methodfor dynamic response analysis of non-linear stochasticstructures[J].International Journal for NumericalMethods in Engineering,2006,65:882―903.
[13]Dassault Systemes Inc.ABAQUS User Manual[DK].2002.
[14]Melchers R E.Structural reliability analysis andprediction[M].Chichester,UK:Ellis Horwood Limited,1987:286―287.
[2]DL/T5339-2006,火力发电厂水工设计规范[S].北京:中国电力出版社,2006.DL/T 5339-2006,Code for hydraulic design of fossil fuelpower plants[S].Beijing:China Electric Power Press,2006.(in Chinese)
[3]Liao W,Lu W D,Liu R H.Effect of soil-structureinteraction on the reliability of hyperbolic cooling towers[J].Structural Engineering and Mechanics,1999,7(2):217―224.
[4]Choi C K,Noh H C.Stochastic analysis of shapeimperfection in RC cooling tower shells[J].Journal ofStructural Engineering,2000,126(3):417―423.
[5]廖汶,卢文达,刘人怀.双曲冷却塔结构非线性有限元可靠度分析[J].工程力学,1999,16(1):49―55.Liao Wen,Lu Wenda,Liu Renhuai.Finite elementreliability analysis of hyperbolic cooling towers[J].Engineering Mechanics,1999,16(1):49―55.(inChinese)
[6]许林汕,赵林,葛耀君.超大型冷却塔随机风振响应分析[J].振动与冲击,2009,28(4):180―184.Xu Linshan,Zhao Lin,Ge Yaojun.Wind-excitedstochastic responses of super large cooling towers[J].Journal of Vibration and Shock,2009,28(4):180―184.(in Chinese)
[7]陈铁云,沈惠申.结构的屈曲[M].上海:上海科学技术出版社,1993:15―16.Chen Tieyun,Shen Huishen.Structural buckling[M].Shanghai:Shanghai Scientific and TechnologicalLiterature Press,1993:15―16.(in Chinese)
[8]李杰,陈建兵.随机结构非线性动力反应的概率密度演化分析[J].力学学报,2003,35(6):716―722.Li Jie,Chen Jianbing.The probability density evolutionmethod for analysis of dynamic nonlinear response ofstochastic structures[J].Acta Mechanica Sinica,2003,35(6):716―722.(in Chinese)
[9]陈建兵,李杰.非线性随机结构动力可靠度的密度演化方法[J].力学学报,2004,36(2):196―201.Chen Jianbing,Li Jie.The probability density evolutionmethod for dynamic reliability assessment of nonlinearstochastic structures[J].Acta Mechanica Sinica,2004,36(2):196―201.(in Chinese)
[10]Li J,Chen J B.The principle of preservation ofprobability and the generalized density evolutionequation[J].Structural Safety,2008,30:65―77.
[11]陈建兵,李杰.随机结构动力可靠度分析的极值概率密度方法[J].地震工程与工程振动,2004,24(6):39―44.Chen Jianbing,Li Jie.The extreme value probabilitydensity function based method for dynamic reliabilityassessment of stochastic structures[J].EarthquakeEngineering and Engineering Vibration,2004,24(6):39―44.(in Chinese)
[12]Li J,Chen J B.The probability density evolution methodfor dynamic response analysis of non-linear stochasticstructures[J].International Journal for NumericalMethods in Engineering,2006,65:882―903.
[13]Dassault Systemes Inc.ABAQUS User Manual[DK].2002.
[14]Melchers R E.Structural reliability analysis andprediction[M].Chichester,UK:Ellis Horwood Limited,1987:286―287.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心