Document: NUREG-0800
Document ID: 6b7eddf4-f7ce-4821-9f11-e37070221e57
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A418.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
necting plate/shell elements and beam elements to solid elements involves special modeling techniques to ensure rotational compatibility and moment transfer. Various techniques have been developed and successfully applied. The connection modeling technique that is implemented is not allowed to result in a reduction or distortion of stress in the plate at the connection. A suitable finite element mesh, consistent with the loading, the expected structural response, and the intended use of the analysis output, needs to be used. The finite element mesh needs to be sufficiently refined to (1) capture the spatial variation of the applied dynamic pressure loading; and (2) accurately respond up to the highest frequency contained in the dynamic pressure loading. A mesh sensitivity study needs to confirm the adequacy of the mesh. The method of applying the dynamic loading to the structural model and the dynamic analysis parameters, which depend on the method of solution, needs to be substantiated. For local areas of the model, where stress output for fatigue analysis will be extracted, it is necessary to check stress convergence by systematically reducing the local element size. The acceptance criterion is that the desired stress output has converged, or that a reasonable projection of the converged stress can be made from the results of the successive mesh refinement analyses. More detailed acceptance criteria, including the specification of the dynamic analysis parameters and the application of the dynamic pressure loading, are described in RG 1.20, Revision 4, Section C.2.1.3.2. (2) High-Cycle Fatigue Evaluation of Two-Sided Fillet Welds 3.9.2-25 Revision 4 – March 2017 Fillet welded connections are common in reactor internals, especially in BWR steam dryers. Stress results from a finite element analysis are typically used in the fatigue evaluation of fillet welded connections. Acceptable approaches depend on the local geometric complexity and the level of model