无缝管壁厚误差对承载能力的影响

Influence of wall thickness error on bearing capacity of seamless pipeline

包钢白云鄂博铁精矿矿浆管道工程采用直径为355.6×15.5mm的X65级无缝钢管,为了获得壁厚误差对承载能力的影响规律,基于俞茂宏统一强度理论,利用解析方法计算管道的弹性极限解和塑性极限解,并进一步分析材料强度参数和拉压比对管道极限承载力的影响,以及塑性极限和弹性极限之间的裕度。结果表明:解析解中包含壁厚与外径的平方比,能够更准确地反映壁厚和外径对弹性极限承载能力的影响;管道的弹性极限承载能力满足设计压力16MPa和试验压力28.2MPa的要求,最小壁厚14.3mm满足安全要求;提高钢管的韧性,可以改善管道的承载能力;管道从弹性极限到塑性极限仅有约8%的裕度。充分考虑钢管壁厚误差,以弹性极限作为设计准则的管道更加安全可靠。

Baiyunebo Iron Slurry Pipeline Engineering of Baotou Steel Works was built by X65 seamless steel pipeline with a diameter of 355.6×15.5 mm. In order to understand the impact law of wall thickness errors in the bearing capacity of pipeline,analytical method based on Yu Hongmao Unifi ed Strength Theory was used to calculate the elastic limit and plastic limit solution of the pipeline and the redundancy between them. The impact of the material strength parameters and tension-compression ratio on ultimate bearing capacity of the pipeline were also analyzed. The results showed that the analytic solution contained the ratio of wall thickness and square of diameter could reflect the impact of wall thickness and diameter on the elastic limit of bearing capacity more accurately. The elastic limit of bearing capacity of the pipeline accorded with the design pressure of 16 MPa and test pressure of 28.2 MPa. The minimum wall thickness of 14.3 mm met the requirements of safety. Improving the toughness of steel could increase the bearing capacity of the pipeline. The redundancy between the elastic limit and plastic limit was about 8%. The results indicated that considering the wall thickness error of the pipeline suff iciently and taking the elastic limit as design criterion could improve the safety and reliability of the pipeline.