含缺陷管件的抗弯曲特性

Bending Resistance of Pipes with Local Defects

评定含缺陷管抗弯曲特性的NSC方法(net-section collapse criterion),所给出的极限弯矩与缺陷长度无关,与实际不符。修正的NSC方法,得到了包含缺陷长度的缺陷管极限弯矩新计算公式。试验结果表明,在缺陷较小的情况下,试验结果与新公式预测值接近而与NSC方法预测值相差较大;在缺陷较大时,三者趋于一致。

In NSC （net-section collapse criterion）, the length of defects is ignored for assessing the bending resistance of pipes with local defects. To modify NSC, a new formula of ultimate bending moment with consideration of defect length was established, J55 oil well pipes with prefabricated local defects were employed to verify the validity of the new formula. The results show that for shorter local defects, the test data agrees with calculated ones predicted by new formula and are different from those predicted by NSC, for longer local defects, three kinds of values are consistent.