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Unformatted text preview: r observations: that for thin, flat elastic structures and regular-shaped elements, SHELL43
does not perform as well as SHELL63. 4. Results for SHELL43 in triangular form are presented, though they are not recommended for use. SHELL43
is based on a hybrid formulation for a quadrilateral element shape. Hence, degeneration of the element
to a triangular shape will show some slight node-ordering dependence on the element solution. ANSYS Verification Manual . ANSYS Release 9.0 . 002114 . © SAS IP, Inc. 2–17 Benchmark C4
5. For the reduced analysis, the TOTAL option is used to automatically select master degrees of freedom.
Masters are chosen in multiples of two, four, and eight times the number of desired frequencies (abbreviated as P). 6. For the reduced analysis using quadrilateral elements, engineering accuracy (2%) is obtained for the first
natural frequency with a total of 18 MDOF ( ≈ 2P) specified. Engineering accuracy for the first eight natural frequencies requires a specification of 72 MDOF ( ≈ 8P). 7. The H...
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