大口径等厚异径焊接斜三通有限元强度分析

Finite Element Strength Analysis of Large Welded Oblique Tee with Different Diameters and Equal Thickness

应用workbench对内压与外载联合作用下的大口径等厚异径焊接斜三通进行了有限元建模和分析,按照ASME规范应力分析法分析了其应力类别及应力组合。在设计载荷下的冯米塞斯等效应力显示,最大应力为234.89 MPa,出现在外侧腹部(管口向左);在操作载荷下最大应力为228.56 MPa,出现在相贯区肩部锐角处,均高于材质的设计应力强度,存在高应力区。为了确定结构承压条件下的安全性,按照JB4732-1995钢制压力容器—分析设计标准中给出的评判依据,对各类计算应力值与材料许用应力值进行比较,从而对高应力区进行了强度校核。根据计算模型的有限元分析结果,通过对选定的评价位置进行应力线性化处理,分析设计工况和操作工况下的应力值,分析结果满足规范要求。

The workbench is used to carry out finite element modeling and analysis of large welded oblique tee with different diameters and equal thickness under the combined action of internal pressure and external load.According to the stress analysis method of ASME code,the stress category and stress combination are analyzed.The Von Mises stress under the design load shows that the maximum stress is 234.89 MPa,which appears on the outer abdomen(the pipe orifice is to the left);The maximum stress under the operating load is 228.56 MPa,which appears on the location of acute angle of shoulder of the junction area.The above two values are higher than the design stress intensity of the material,which proves that the high-stress areas exist.In order to determine the safety of the structure under pressure,according to the judgment basis given in JB4732-1995 Steel Pressure Vessel-Analysis and Design Standard,various calculated stress values and allowable stress value of material are compared,and the strength check is conducted in the high-stress areas.According to the finite element analysis results of the calculation model,the stress linearization process is conducted on the selected evaluation location to analyze the stress values under the design conditions and operating conditions,and the analysis results meet the requirements of the specification.