I am currently reposting this question due to incorrect solution in previous solution it said that external pressure is $0$ which is not the case since in my question internal pressure is $0.$ Elastic modulus$=200$ GPa $,$Poissons Ratio$=0\mathrm{.}3,$r$1=50$mm $,$r$2=100$mm$,$p$=100$ N$/$mm$2.$ I need to find the maximum shear stresses at point m and n

$.($cylinderical coordinates are used so consider sigma r

$,$sigma theta and shear stress r theta.$)$