He needed a thicker section. Or a fillet at the support. Or both.
Step by step, he followed Khurmi’s method. First, find the reaction. Then the shear force diagram. Then the maximum bending moment at the fixed end. He calculated the moment of inertia for a square section. Then the section modulus. Then stress. R S Khurmi Strength Of Materials
Khurmi listed them like a judge delivering verdicts: Maximum principal stress theory (Rankine). Maximum shear stress theory (Guest’s). Arjun chose the latter for ductile materials. He recalculated. Still failure. He needed a thicker section