Research On Stress Analysis And Reinforcement Design Of Spherical Shell With Transnormal Flush Nozzle

It is important to analyze the stresses and reinforcement design of spherical shell with transnormal nozzle because it is widely used in petroleum > chemicaK nuclear electric and other industries.First of all, in order to explore and master the characteristic of stress distribution on this structure and to find reinforcement design which can accommodate to different instances, the stresses of a series of models with different t/T and r/R were analyzed by the finite element procedure-ANSYS. Atlas of stress distribution and graphs of stress concentration factor(SCF) were obtained. The atlas and the graphs showed that the SCF at the joint crease nonlinearly with the accretion of r/R and the minuet of t/T. For confirming the results, a full-size model(dj/Dj=0.6, t/T=1.5) was analyzed by means of strain gauge test. The reliability of finite element analysis was proved because the results basically accorded with that of the test.Secondly, in this paper, in order to carry out a fair assessment of the reinforcement design on spherical shell with transnormal nozzle, a comparison of reinforcement method was done between JB4732-1995 Steel Pressure Vessels桪esign by Analysis appendix A4 and HG20582-1998 Specification for Stress Calculation of Steel Chemical Vessels. In most cases, it was found that the JB criterion is safer than HG specification, but adverse result was obtained when r/R is close to 0.8 and D/T is too small(less than 40). Code in C language was worked out for simplifying the calculation.In addition, the C language procedure for stress analysis calculate on connective structure between spherical head and cylindrical shell in JB4732-1995 Steel Pressure Vessels桪esign by Analysis appendix A2 "strain and stress of basic parts" was adopted. Therefore, the complicated process can be accomplished by computer.