Answer:
The question is a problem that requires the principles of fracture mechanics.
and we will need this equation below to get the Max. Stress that exist at the tip of an internal crack.
Explanation:
Max Stress, σ = 2σ₀√(α/ρ)
where,
σ₀ = Tensile stress = 190MPa = 1.9x10⁸Pa
α = Length of the cracked surface = (4.5x10⁻²mm)/2 = 2.25x10⁻⁵m
ρ = Radius of curvature of the cracked surface = 5x10⁻⁴mm = 5x10⁻⁷m
Max Stress, σ = 2 x 1.9x10⁸ x (2.25x10⁻⁵/5x10⁻⁷)⁰°⁵
Max Stress, σ = 2 x 1.9x10⁸ x 6.708 Pa
Max Stress, σ = 2549MPa
Hence, the magnitude of the maximum stress that exists at the tip of an internal crack = 2549MPa
