FZ28-105闸板防喷器承压件在装配体下的应力计算

Stress calculation of the assembled pressure parts of FZ28-105 ram BOP

闸板防喷器关键承压件三维模型有限元分析目前存在一定的局限性。为此,利用Cosmosworks有限元分析软件开展了FZ28-105闸板防喷器的壳体及侧门等关键承压件的力学分析。在装配体下先定义防喷器计算的约束边界、载荷及其有限元网格等条件,把装配体中的壳体与侧门在载荷的冲击下作为整体分析,然后分别在额定工作压力(157.5MPa)和静水压力(105MPa)试验条件下进行应力分析计算。结果表明:最大应力都发生在壳体垂直通孔与长圆形通孔相贯的上壁,为减少其应力的过度集中,在设计中应将该处作倒角处理;静水压试验压力载荷状态的上壁应力值达到591.2 MPa,额定工作压力状态的上壁最大等效应力值为391.2MPa,均小于屈服极限值785MPa,壳体处于弹性状态,壳体、侧门设计强度符合API规范,说明该设计是安全的。该成果为成功试制FZ28-105闸板防喷器提供了关键的支持数据。

There exists a certain limit in the 3D finite element modeling in the analysis of those key pressure parts of ram blowout pre venter （BOP）. Therefore, the Cosmosworks FEA software was adopted instead to conduct a mechanical analysis of such key pres sure parts as the shell and side doors of FZ28 105 ram BOP. First, define such conditions as the constraint boundary, load and its fi- nite element gridding. Second, analyze the shell and side doors as an integral part in the assembly under the load impact. Third, ana lyze and calculate the stress under the experimental condition respectively at the rated working pressure of 157.5 MPa and the hydro static pressure of 105 MPa. The calculation results show that both maximum stresses are located at the superior wall where the verti cal through-hole and the long round through-hole intersect on the shell, and these positions should be chamfered in design to reduce excessive stress concentration; the superior wall stress reaches 591. 2 MPa under the load condition of hydrostatic test pressure, while the maximum equivalent stress of the superior wall is 391.2 MPa at the rated working pressure; both stress values are smaller than the yield limit of 785 MPa, indicating that the shell is in an elastic state. In conclusion, the shell and side doors are designed in line with API specifications, proving the safety of this design and providing crucial support data for successful trial-manufacture of FZ28 105 ram BOP.