针对大长细比起重桁架臂结构稳定性问题,以VS2012为开发平台,利用C#编制大长细比起重桁架臂结构稳定性多理论计算软件,研究4种设计理论和方法(线性理论许用应力法、非线性理论许用应力法、线性理论极限状态法和非线性理论极限状态法)的适用性与科学性,通过对比这4种方法的广义裕度获得最优理论和方法.结果表明:在满足臂架稳定性条件下,非线性理论极限状态法具有最小的广义裕度,材料的利用率最高,表明基于小位移假定的线性理论不适宜大长细比起重桁架臂结构的稳定性设计计算,而非线性理论极限状态法则更适合载荷与内力呈非线性的大长细比起重桁架臂结构场合,计算结果更贴近结构实际状态.%To study the structural stability of crane truss arm with a large slenderness ratio, a multi-theory calculation software is developed with C# on VS2012 development platform to analyze whether four design theories and methods (linear theory of allowable stress method, nonlinear theory of allowable stress method, linear theory of limit state method and nonlinear theory of limit state method) are applicable and scientific. Optimal theories and methods are obtained by comparing general margins of the four methods. It turns out that, when the beam is appropriately stable, the nonlinear theory of limit state method gets the minimum general margin and the maximum material utilization rate, indicating that the linear theory based on small displacement assumption is not suitable for the stability design calculation of crane truss arm with a large slenderness ratio, while the method is more applicable to the case where the load and inner force are in nonlinear relation, and calculation result is more close to the actual status of the structure.
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