Thermo elastic-plastic transition of non-homogeneous thick walled circular cylinder under internal pressure

Effect of non-homogeneity on elastic-plastic transition in a thick walled circular cylinder under internal pressure and temperature has been investigated by using Seth's transition theory. The non-homogeneity is assumed due to variation of modulus of compression. Expressions for stresses required for initial yielding and fully plastic have been obtained. The results for combined effect of pressure and temperature are depicted graphically. It has been seen that in the presence of temperature. a cylinder made of non-homogeneous material K < 0 (Non-homogeneity is less at internal surface than at outer surface) require high pressure to become fully plastic as is required for initial yielding and this pressure goes on increasing with the increase in temperature, showing that a cylinder made of non-homogeneous material K < 0 is on the safer side of design.