椭圆度对直埋供热弯头应力的影响

The Effect of Ellipticity on Directly Buried Heating Bend Stress

针对DN1200、DN1000、DN800供热直埋弯头,采用有限元方法模拟分析同一位移荷载、压力荷载、温度荷载和曲率半径下,不同椭圆度弯头的应力大小和规律。结果表明,管道在施加位移荷载、压力荷载和温度荷载后,弯头中性线处应力最大,且随着椭圆度的增大,应力值先降低后增大;如果弯头具有一定的椭圆度,且将椭圆度控制在一定范围内,对直埋供热弯头的受力是有益处的。

In the machining process of bend,there exists some defects like uneven wall thickness and cross section ovalisation which can influence the size and distribution of stress.Aimed at three different bends with the diameters of DN1200,DN1000 and DN800,this article analysed the size and distribution of stress of bends with different ellipticity by using the method of finite element simulation in the condition of same displacement load,internal pressure,temperature load and curvature radius.The results show that the location of maximum stress is in the neutral line of bend after applied displacement load,internal pressure and temperature load,and the value of maximum stress first decreased then increased with increasing ellipticity.According to the results,it is favorable if the bend has moderate ellipticity and the ellipticity is controlled in a certain range.