【摘要】 弯管在管线中通常是承受应力较大的元件 ,极限载荷相应较低。为充分发挥结构的塑性极限承载能力 ,对弯管的塑性极限载荷进行理论分析 ,利用vonMises屈服准则 ,推导出内压和扭矩联合载荷作用下等厚弯管、非均匀壁厚椭圆弯管的塑性极限压力。实验验证了理论分析的正确性更多还原

【Abstract】 In the piping system, the pipe bends are normally found to be the most highly stressed piping components, and has a lower plastic collapse load. Plastic collapse loads are used for establishing allowable loads, i.e., loads above which large increases in deformation occur with small increases in load, the resulting large deformations are link to plastic flow. Although these occur only in the ideal material, they can be applied to structures, such as pipe bends. Some work has been published on the plastic collapse load of smooth pipe bends subjected to single loading such as in plane bending or internal pressure, but there is not report now how to get the plastic collapse load of pipe bends with irregular geometry under the combined loadings. So this is the main purpose presented here. By using limit analysis method and von Mises yield criteria, the theoretical analysis of the plastic collapse load for the pipe bends are carried out. The pipe bends are circular cross section, elliptical circular cross section and nonuniform thickness respectively, the plastic collapse load equations for bends under the loadings of internal pressure and torsion are obtained. By simplified, the plastic collapse load of the pipe bends subjected to single loading can be easily achieved. Some results have been verified by experiments. Therefore, this paper is useful for safety assessment of the undefected pipe bends and provides a method to solve the plastic collapse load for defected bends.更多还原