复杂桁架内力计算中的“零杆判断”

Judge of Zero-pole in Internal Force Calculation of Complex Truss

针对复杂桁架的内力计算,内力计算最为常用的方法有两种,即结点法和截面法,传统方法求桁架中杆件的内力,对于结点数较多或较复杂的桁架并不太适用.在特殊情况下对几种结构内力特点的分析,归纳总结了5种零杆判断方法,即利用特殊节点判断零杆、利用整体法与结点的平衡相结合判断零杆、利用截面法判断零杆、利用对称结构性质判断零杆和利用假设法判断零杆.通过归纳总结的零杆判断方法,为快速计算复杂桁架的内力提供了可靠的理论依据.

For the internal force calculation of complex truss,there are two commonly used methods,namely node method and section method. The traditional method for internal force of the bar is not applicable,specially for the truss with many junction points or more complex structure. Through the analysis of several structural internal force characteristics under special circumstance,five judging methods of zero-pole are summarized. That is,judging the zero-pole with special node,judging the zero-pole combined the integral method with the balance of the node,judging the zero-pole by the cross section,judging the zero-pole by the property of symmetric structure and judging the zero-pole by hypothesis method. Meanwhile,these judging methods provide a reliable theoretical basis for fast internal force calculation of complex truss.