长输管道焊接修复结构的全尺寸实验

完成了一组"扣帽子"和"补板"两种形式的管道焊接修复结构的全尺寸爆破试验,测量了修复结构中的爆破压力和应变分布,并分析了应力集中、屈服极限载荷等。结果表明,修复结构的屈服极限和完好管道相比有所降低,最低为完好管道屈服极限的85%,而各种修复结构的爆破压力基本相同,约为完好管道爆破压力的96%,爆破是由于最大剪应力的韧性过载引起的韧性破坏;单孔管道的破裂位置均远离焊接结构处,多孔管道的爆破发生在两管帽之间,说明多管帽修复结构不利于管道承压;修复结构存在一定程度的应力集中,疲劳试验的结果还表明,修复结构有较好的抗疲劳破坏能力。通过试验,验证了管道焊接修复结构的承压能力。

Full Size Experiments of Welding-repaired Pipelines

A set of the full scale burst experiments were conducted for the two kinds of welding-repaired pipelines,welded either a tube cap or a patch,their strain distributions were measured,and their stress concentration and yield and burst load were analyzed.The results showed that the yield limit loads of the repaired pipelines decreased,among which the lowest one decreased up to 85% of that of the pipeline that were not damaged,whereas their burst pressures remained the same,being equal to about 96% of that of the pipeline that were not damaged.The burst was a ductile fracture resulted from the maximal shear stress.On the pipelines with a single drilled hole the burst occurred far from the welding sites,whereas on the pipelines with several holes drilled in short span the burst took place between the two adjacent tube caps,suggesting that multi-cap repair is disadvantageous to the loading capability of the pipelines.Welding repair resulted in the stress concentration in a certain degree.Furthermore,results show that repaired pipelines still have a good anti-fatigue capability.The full-size experiments in this paper have demonstrated the loading capacity of the repaired pipelines.