广西大学学报（自然科学版）
廣西大學學報（自然科學版）
엄서대학학보（자연과학판）
JOURNAL OF GUANGXI UNIVERSITY （NATURAL SCIENCE EDITION）
2015年
4期
1012-1018
,共7页
桥梁工程%可靠性%斜拉桥%综合分析法%随机有限元法%概率分布%数值特征
橋樑工程%可靠性%斜拉橋%綜閤分析法%隨機有限元法%概率分佈%數值特徵
교량공정%가고성%사랍교%종합분석법%수궤유한원법%개솔분포%수치특정
bridge engineering%reliability%cable bridge%comprehensive analysis method%stochas-tic finite element method%probability distribution%numeric attributes
鉴于目前复杂桥梁结构可靠性分析方法的局限性,提出一种新的可靠性综合分析方法。在随机有限元法的基础上,结合了几种常用可靠度计算方法的优点,能较方便得出复杂结构极限状态方程的概率分布及数值特征,进而求得相应的结构可靠度指标及失效概率,可为复杂桥梁结构的可靠性分析提供新的思路。以某大跨径斜拉桥为研究对象,采用ANSYS程序建立随机有限元模型,将结构材料特性、荷载及材料强度等参数模拟成随机变量,采用综合分析法对大桥进行可靠性分析。研究结果表明：在承载能力极限状态下,大桥斜拉索最低可靠度指标为5.89,桥塔的可靠度指标为6.37,主梁最低可靠度指标为5.29,均高于规范容许值4.7,相应最大失效概率为1.01×10-8。正常使用极限状态下,大桥跨中挠度可靠度指标高达3.43,也高于容许值,失效概率仅为3.02×10-4。表明大桥在两种极限状态下均具有较高的可靠性。
鑒于目前複雜橋樑結構可靠性分析方法的跼限性,提齣一種新的可靠性綜閤分析方法。在隨機有限元法的基礎上,結閤瞭幾種常用可靠度計算方法的優點,能較方便得齣複雜結構極限狀態方程的概率分佈及數值特徵,進而求得相應的結構可靠度指標及失效概率,可為複雜橋樑結構的可靠性分析提供新的思路。以某大跨徑斜拉橋為研究對象,採用ANSYS程序建立隨機有限元模型,將結構材料特性、荷載及材料彊度等參數模擬成隨機變量,採用綜閤分析法對大橋進行可靠性分析。研究結果錶明：在承載能力極限狀態下,大橋斜拉索最低可靠度指標為5.89,橋塔的可靠度指標為6.37,主樑最低可靠度指標為5.29,均高于規範容許值4.7,相應最大失效概率為1.01×10-8。正常使用極限狀態下,大橋跨中撓度可靠度指標高達3.43,也高于容許值,失效概率僅為3.02×10-4。錶明大橋在兩種極限狀態下均具有較高的可靠性。
감우목전복잡교량결구가고성분석방법적국한성,제출일충신적가고성종합분석방법。재수궤유한원법적기출상,결합료궤충상용가고도계산방법적우점,능교방편득출복잡결구겁한상태방정적개솔분포급수치특정,진이구득상응적결구가고도지표급실효개솔,가위복잡교량결구적가고성분석제공신적사로。이모대과경사랍교위연구대상,채용ANSYS정서건립수궤유한원모형,장결구재료특성、하재급재료강도등삼수모의성수궤변량,채용종합분석법대대교진행가고성분석。연구결과표명：재승재능력겁한상태하,대교사랍색최저가고도지표위5.89,교탑적가고도지표위6.37,주량최저가고도지표위5.29,균고우규범용허치4.7,상응최대실효개솔위1.01×10-8。정상사용겁한상태하,대교과중뇨도가고도지표고체3.43,야고우용허치,실효개솔부위3.02×10-4。표명대교재량충겁한상태하균구유교고적가고성。
In view of some limitation in the reliability analysis of bridge structures at present, a new comprehensive analysis method was put forward. Based on the stochastic finite element and com-bined with the advantages from the common reliability analysis methods, the new method could con-veniently obtain the probability distribution and numeric attributes of limit state equation of complex bridge structures, and then obtain the reliability index and failure probability, which could provide a new idea for reliability analysis of complex bridge structures. Taking a long-span cable bridge as the research object, its stochastic finite element model was built using ANSYS, some parameters such as material properties, loads, material strength, and so on, were simulated as stochastic variables in this model, and the new method was used to analyze the bridge’s reliability. The analysis results show that, in the ultimate limit state, the lowest reliability indexes of cables, bridge towers and gri-der are 5. 89, 6. 37 and 5. 29, respectively, all of which are higher than the allowable value 4. 7, and the maximum failure probability is 1. 01×10-8. In the serviceability limit states, the reliability index of the mid-span deflection reach 3. 43, which is also higher than the allowable value, and its failure probability is 3. 02 ×10-4 . The results prove that the long-span cable bridge has a higher reli-ability.
