Dhaval,
If your geometry is well within the WRCB-107 geometry criteria, then dont go for WRCB-297. If your geometry is not within the limitations of WRCB-107, then you must go for WRCB-297 and check whether your geometry fall in the same. If yes then you must use WRCB-297. If it is not falling within WRCB-297 limits then go for Finite Element Analysis.
Remember one thing WRCB-297 is supplementary code to WRCB-107.
Also as Ray have said both working on different concepts so results would be definitely different.
Thanks.
Mukesh
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