摘要
为研究钢构件弯扭屈曲总势能方程的合理性,该文通过分析推导总势能方程的两个方法——应力法和应变法的基本过程,揭示了应变表达式和位移模式是影响总势能方程推导结果的两个关键因素,建立了这两个关键因素合理性的判定准则,并验证了准则的正确性。依据该文建立的准则,对两种典型位移模式和三种典型总势能方程进行了判定。结果表明:符拉索夫位移模式较Trahair位移模式更为合理,吕烈武等学者的总势能方程较Bleich的总势能方程和Trahair的总势能方程更为合理。最后,建议了推导钢梁临界弯矩Mcr设计公式应采用的总势能方程。
In order to study the rationalization of the total potential energy equation of steel members with flexural-torsional buckling,the deriving procedure of stress method and strain method is analyzed in this paper.It is found that the expressions of strains and displacement mode are the two primary factors that affect the results,then two criteria on the rationalization of the two primary factors are established,and the correctness of the two criteria is verified.By using the two criteria,two typical displacement modes and three typical total potential energy equations are judged.The conclusion showed that Vlasov’s displacement mode is more reasonable than Trahair’s,and Lü’s total potential energy equation is more rational than Bleich’s and Trahair’s.Finally,a total potential energy equation which should be adopted for deriving the design formula of critical moment Mcr is proposed.
引文
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