Determine the maximum shear stress:
A beam of triangular cross section of base width 120 mm & height 80 mm is subjected to a shear stress force of 3 kN. Determine the maximum shear stress & the shear stress at the neutral axis.
Solution
Maximum shear stress is at a distance h/2 from the base of the triangle.
Maximum shear stress, τ_{max} = 3F / bh
τ _{max} = (3 × 3000) / (120 × 80 )= 0.94 N/mm2
Shear stress at the neutral axis,
τ_{NA} = (8/3) ×( F/bh)
= (8/3) × 3000/(120 × 80)
= 0.83 N/mm^{2}