On the mechanical and thermal transient analysis of cylinder-to-cylinder vessels by a finite plate method

A problem common to the pressure vessel analyst is the evaluation of stresses in nozzle-to-cylinder structures subjected to internal pressure, nozzle axial force and nozzle moments. The finite plate method, discussed by Brown in a paper on nozzle-to-cylinder structures subjected to internal pressure, is extended to include axial force and moments at the nozzle terminus. The purpose is to provide an economical alternative to 3-D geometric analytical and experimental stress analysis of such structures. The theoretical development of the geometric and pressure load parameters is briefly reviewed. The analytical development of the parameters for axial force, inplane moment and out of plane moment is presented in detail. The range of applicability is reviewed for the various types of loading. Examples are presented for nozzle-to-cylinder structures loaded by pressure, axial nozzle force, inplane moment at the nozzle and out of plane loading at the nozzle. Finite plane results are compared with the ORNL model No. 3 data obtained by strain gauge and 3-D finite element methods and loaded by nozzle loads. The finite plate results versus the experimental data obtained by Van Campen and 3-D finite element data for internal pressure are briefly discussed. In all instances the data compare favourably at the critically stressed location which is at the nozzle-to-cylinder juncture. A comparison of 3-D finite element, 2-D finite element with the finite plate assumptions and some 2-D finite element nozzle-to-hemisphere data from thermal loading is presented. Finally, some observations are made with respect to the assessment of nozzle loads not analytically treated. (author)