核电站安全壳钢衬壳环的屈曲研究

核电站安全壳内的钢衬在机械载荷或热载荷作用下,受到环向压力和轴向压力,过大的压力会导致钢衬的屈曲变形,进而使钢材发生局部破裂,丧失其限制放射性物质泄漏的作用。为研究锚固于核电站重要设施安全壳混凝土壁上的圆完环在环向压力作用下的屈曲问题,考虑到一般大径厚比的壳环其最大屈曲挠度大于其厚度,应用非线性大挠度壳环方程,分析了锚固钢材壳环的局部屈曲和全域屈曲的后屈曲性态,获得了完整的后屈曲平衡路径,讨论了钢衬壁厚和锚固间距对屈曲性态的影响。结果指出,增大钢衬厚度、减小锚固间距能大大提高钢衬的承载能力,且试验结果说明理论分析是可行的。

Circumferential buckling of steel liners for the containment in NPPs

The thin steel liner of the containment in nuclear power plants (NPPs) likely to buckle inward as the liner is compressed due to the internal temperature rise in use or in abnormal condition. This paper deals with the case of a hollow circular ring encased in a concrete circular cavity with anchors. When the concrete is pre-stressed and the internal temperature rises in use, The ring is compressed in the circumferential direction and the increased hoop stress may cause the ring to buckle inward. For a ring with a small thicknessradius ratio, tile: amplitude of the buckling is larger than the thickness of the ring. So the buckling problem involves large deflections with a restraining condition that the radial deflection is allowed only in the inward direction. The large deflection non-linear equation in the buckling state is solved analytically. Complete load displacement curves are presented and show .hat there are several possible equilibrium states after the circumferential pressure exceeds a certain critical value. The critical pressure is affected dramatically by the thickness of the liner and the spacing of anchors. The comparison of experimental results with theory analysis confirms that the theory analysis is feasible and effective. The results of this study can be "red to determine the circumferential spacing of anchors for cylindrical liner shells.