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concentration factors (SFCs) are made with theoretical SCFs and found that all results
are identical and have very good agreements for axial tension and bending loading but
deviate very much for torsional loading. Experimental work performed on round bars
made from Polycarbonate rod serves as photoelastic material, using photoelastic
apparatus. During experimentation, proper fringes are not visible on a workpiece. To
resolve this problem of non-visibility of fringes on a workpiece, another approach, partial
slicing of the model is carried out but buffing is not possible in the narrow portion of
shoulder fillet of round bar and still the fringes are not visible on the round bar. To
overcome this difficulty, slicing of a workpiece (flat plate and curved plates) is carried out
with the concept of different thickness. FEA and experimental work are carried out for all
slice models. From the FEA results of slice models of different thickness, SCF for flat
plates, curved plates, rapport factor for SCF and equivalent SCF for a round bar (after
multiplying with rapport factor) are calculated and presented in the form of charts. Also
from the optimum (h = r) condition, different r/d ratios are prepared and by using same
r/d ratios and D/d ratios, SCF from Peterson graphs are obtained and it is compared with
SCFs (from FEA) for axial tension, bending and torsional loading for different thickness of
plates and found all the results are identical and have very good agreements with
theoretical SCF and SCF obtained by FEA. Ultimately, one can utilize the modified
equations of fillet radius (r) in terms of SCF (K ) for optimal condition and directly select
t
the optimal value of SCF from a derived range of SCF for different loading conditions as
per their applications.
Keywords: Stress concentration factor (SCF), Axial tension loading, Bending loading,
Torsional loading, Finite element of analysis (FEA), Photoelasticity, Round bar

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