Answer:
Maximum allowable surface crack length = l = 0.000611m
Explanation:
Tensile stress = σ = 1.25 MPa = 1.25 × 10^6 N/m2
Surface energy of polystyrene = Es = 0.50 J/m2
Elastic Mudolus = E = 3 GPa = 3 × 10^9 N/m2
Maximum allowable surface crack length = l = ?
We know that:
l = 2EEs/πσ^2 ....... (i)
By putttin the values in equation (i)
l = (2)(0.50)(3 × 10^9)/(3.14)(1.25 × 10^6)^2
l = 0.000611m
Hence, the Maximum allowable surface crack length will be 0.000611m.
