国内外1.5D弯头壁厚设计标准对比

Design Standard Comparison for 1.5D Bend Thickness in China and the Abroad

对1.5D管线钢弯头承受内压时的受力情况进行了分析,计算得出弯头承受内压时周向应力的分布是:内侧最大,外侧最小,内外侧分界处(即中性层)与直管相同。对比了GB 50251—2003,SY/T 0518—2002和国外标准ASME B31.3—2004对弯头壁厚的设计要求,并通过压力试验进行了验证,认为ASME B31.3—2004标准对弯头壁厚的设计理论更为合理,即在同等壁厚条件下,弯头内弧受力大于外弧及中性层。使用ASME B31.3—2004标准设计弯头,既能满足内外弧受力要求,又在一定程度上节约了原料成本。

The force of 1.5D pipeline steel bend under inside pressure was analyzed,and the circumferential stress distribution of bend was achieved,the stress value of intrados is the maximum,the extrados stress value is the minimum,the stress value of neutral layer is the same with that of straight pipe.The design requirements for bend thickness in GB 50251 2003 and SY/T 0518-2002 were compared with those in ASME B31.3-2004,it was validated through pressure test,the result indicated that the design theory for bend thickness in ASME B31.3-2004 standard is more reasonable.With the same thickness,the stress value of intrados is bigger than that of extrados and neutral layer.Adopting ASME B31.3-2004 standard to design bend,it can not only meet force demand of intrados and extrados,but also save material cost in a certain extent.