大型轴流压缩机焊接机壳结构特性有限元分析

在建立大型轴流压缩机焊接机壳有限元模型的基础上,对联接螺栓台阶面与上机壳法兰面之间、上下机壳法兰面之间的接触问题以及螺栓的预紧问题进行了处理,并应用有限元分析软件对模型进行了分析计算。计算结果表明焊接机壳静态下的应力和变形均在允许范围内。热-应力耦合作用下的应力分布规律及机壳整体变形结果显示,机壳直径变化处圆周上的应力变化达30~240 MPa,局部超过300 MPa;进气口一侧中分面法兰上的部分螺栓的应力已超过700 MPa,接近螺栓材料的屈服极限(720 MPa);机壳的径向和轴向变形量分别达16 mm和15.4 mm。

Finite Element Analysis of Structural Characteristics on Welded Casing of Large Axial Compressor

Based on the finite element(FE) model of welded casing for large axial compressor,the problem of surface-contact between bolted flange & the top casing flange and the top casing flange & bottom casing flange as well as the problem of pre-load of bolts were dealt with in this paper.The model was analyzed with FE analysis software.The finite element analysis software was used to analyze and calculate the model.The calculated results indicate that the static stress and distortion of all the designed welded casings are within the permited range.The distribution of stress and distortion when both thermal-stress and force act on the casing indicate that the stress around the welded casing changes from 30 to 240 MPa where the diameter changing,part stress beyond 300 MPa;stress of some bolts on the mid flange of gas inlet beyond 700 MPa, approach the yield stress of the bolt material(720 MPa),the radial distortion is 16 mm and axial is 15.4 mm.