Answer:
22.5 N/mm^2; 0.196 MPa.
Explanation:
maximum shear stress can be defined as the difference between hoop stress and the longitudinal stress all divided by two(2). It can be represented mathematically by;
maximum shear stress =( hoop stress - longitudinal stress)/ 2.
To Calculate the hoop stress, we need the formula below:
[Internal pressure (p) × diameter (d)] ÷ 2 × thickness (t).
==> 1.2 × 250/ 5× 2= 30 N/mm^2 = 30 MPa.
Longitudinal stress can be calculated using the formula below;
Internal pressure (p) × diameter (d)] ÷ 4 × thickness (t).
==> 1.2 × 250/ 4 × 5 = 15 N/mm^2 = 15 MPa.
Therefore, maximum shear stress =( hoop stress - longitudinal stress)/ 2.
maximum shear stress = (30 + 15)/2.
=> 22.5 N/mm^2.
===> Normal stress = Axial force P/Area.
=20 kN/ (2πr^2 + 2πrh).
= 20000N/ ( 2× 3.143 × 125^2 + 2 × 3.143 × 125 × 5).
= 20000/( 98218.75 + 3928.75).
= 20000/ 102147.5.
= 0.196 MPa.