公路交通科技
公路交通科技
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JOURNAL OF HIGHWAY AND TRANSPORTATION RESEARCH AND DEVELOPMENT
2010年
2期
79-84
,共6页
桥梁工程%曲线粱桥%能量守恒原理%振型%方向参数%弯扭耦合
橋樑工程%麯線粱橋%能量守恆原理%振型%方嚮參數%彎扭耦閤
교량공정%곡선량교%능량수항원리%진형%방향삼수%만뉴우합
bridge engineering%curved bridge%energy conservation principle%mode shape%direction parameter%flexure-torsion coupling
由于曲线梁桥独特的构造特点,其振型存在"弯扭耦合"现象.为了判定曲线梁桥各阶"弯扭耦合"振型的主方向是弯曲或纯扭转,把曲线梁桥的每阶振型分解为竖向弯曲、纯扭转、横向弯曲和纵向移动4个子方向,把每阶振型的能量亦分成竖向弯曲能量、扭转能量、横向弯曲能量和沿纵向平移能量4个方向上的能量,引入4个方向参数来分别表示各子方向能量所占各阶振型能量的比值.然后从结构动力学理论知识出发,根据无阻尼系统每阶振型动能和变形能之和为常数的基本原理,推导了4个方向参数的计算公式,推导结果显示,方向系数仅为结构质量、截面几何特性和振型向量的表达式.最后提出了一种根据方向参数值的大小判定曲线梁桥各阶振型以哪个子方向为主的方法,并通过实例介绍了该方法的应用.
由于麯線樑橋獨特的構造特點,其振型存在"彎扭耦閤"現象.為瞭判定麯線樑橋各階"彎扭耦閤"振型的主方嚮是彎麯或純扭轉,把麯線樑橋的每階振型分解為豎嚮彎麯、純扭轉、橫嚮彎麯和縱嚮移動4箇子方嚮,把每階振型的能量亦分成豎嚮彎麯能量、扭轉能量、橫嚮彎麯能量和沿縱嚮平移能量4箇方嚮上的能量,引入4箇方嚮參數來分彆錶示各子方嚮能量所佔各階振型能量的比值.然後從結構動力學理論知識齣髮,根據無阻尼繫統每階振型動能和變形能之和為常數的基本原理,推導瞭4箇方嚮參數的計算公式,推導結果顯示,方嚮繫數僅為結構質量、截麵幾何特性和振型嚮量的錶達式.最後提齣瞭一種根據方嚮參數值的大小判定麯線樑橋各階振型以哪箇子方嚮為主的方法,併通過實例介紹瞭該方法的應用.
유우곡선량교독특적구조특점,기진형존재"만뉴우합"현상.위료판정곡선량교각계"만뉴우합"진형적주방향시만곡혹순뉴전,파곡선량교적매계진형분해위수향만곡、순뉴전、횡향만곡화종향이동4개자방향,파매계진형적능량역분성수향만곡능량、뉴전능량、횡향만곡능량화연종향평이능량4개방향상적능량,인입4개방향삼수래분별표시각자방향능량소점각계진형능량적비치.연후종결구동역학이론지식출발,근거무조니계통매계진형동능화변형능지화위상수적기본원리,추도료4개방향삼수적계산공식,추도결과현시,방향계수부위결구질량、절면궤하특성화진형향량적표체식.최후제출료일충근거방향삼수치적대소판정곡선량교각계진형이나개자방향위주적방법,병통과실례개소료해방법적응용.
Due to the special comtruction feature,the mode shape of a curved bridge has "flexure-torsion coupling" situation.In order to determine whether the main direction of the mode shape is flexure or torsion,each mode shape was divided into four sub directions which are vertical bending,pure torsion,transverse bending and longitudinal shift respectively.Accordingly,the energy of each mode was also subdivided into four directions.The ratios between the energy of sub direction and the total energy of a mode were denoted by four direction parameters.Theoretical derivation for the direction parameters was given based on the energy conservation principle of each mode of undamped system.The derivation result reveals that four formulas of the direction parameters are only related to structural mass,sectional geometric characteristics and mode vectors.Finally,the method of determining the main sub direction of mode shapes of a curved bridge was given according to the values of the four parameters,and how to use the method was presented too by a instance.