摘要:基于失效评定图技术理论,根据贮氢压力系统结构、材料和载荷特点,制定结构安全评定程序及项目.缺陷检测结果表明:贮氢压力系统主缺陷为焊缝底端未焊透.将其表征为三参量矩形环向缺口,结合材料性能数据,通过有限元应力求解可知:离心及内压综合载荷作用下最大等效应力出现在未焊透根部两侧尖端,随缺陷深度增加而增大,且变化趋势基本成线性关系;随宽度减小而增加,但宽度值大于0.5 mm后,最大等效应力基本不再变化.计算贮氢前后不同深度缺陷失效评定点Lr和Kr值,绘于失效评定图中,评定结论如下:当未焊透缺陷深度不超过60%壁厚时,结构是安全的,安全系数大于1.5;结构失效模式为塑性失稳,长期贮氢后由于材料断裂韧度的下降及缺陷的扩展,失效模式将逐步由塑性失稳转为弹塑性断裂,但效应并不显著.%Base on failure assessment diagram method, the procedure and item on safety assessment of hydrogen storage pressure system were established according to the features of system's structure,material and load. The results of flaw detection show that the main flaw of hydrogen storage pressure system is lack of penetration ( LOP) . LOP flaw can be attributed to rectangular section circumferential notch. The stress of flaw field was calculated by FEA. The results show that the maximum equivalent stress is in the region of LOP bottom margin under pressure and centrifugal load environment. The maximum equivalent stress increases with the increase of flaw depth, and decreases with the increase of flaw width. The depth of LOP is primary influence factor to maximum equivalent stress because of notable stress concentration effect. The failure assessment points of various depth flaws was calculated and plotted in failure assessment diagram. The results are as follow: when flaw depth is not above 60% shell thickness, the structure is safe and safety factor is over 1.5. Failure mode is plastic instability. After long - time hydrogen storage, the fracture toughness decreases and flaw depth increases. Failure mode converts to elastic - plasticity fracture, but effect is not serious.