FATIGUE ANALYSIS OF PRESSURE VESSELS USING VARIOUS STIFFENERS

Pressure vessels are used to store or hold the liquids and gases substantially at a pressure greater than that of the ambient pressure. Rocket motor casing is acts as pressure vessel and subjected to different dynamic loads while moving through the atmosphere. Cyclic or alternate loads are one of the dynamic load which acts on the rocket motor casing. So fatigue factor comes into existence in such conditions. From the literature, pressure vessels fails quickly when the fatigue loads acts. The failure of the pressure vessels takes place at half of the maximum stress of material when fatigue loads comes into picture. A fatigue condition of fully reversed cycle with soderberg equation is chosen for this problem. Soderberg equation deals with yield stresses. Finite element analysis software is used to solve the life, damage and Safety factor for the stiffener designs. The stiffener designs used in the present work are circular, rectangular, helical, sector, rectangular slotted, linear x-crossed and quadratic xcrossed. From the parameters considered, best stiffener subjected to fatigue loads was concluded