3069 - STRESS INTENSITY FACTORS FOR COMBINED TEMPERATURE GRADIENT AND INTERNAL PRESSURE FOR DAMAGED CYLINDERS

It is not unusual for cylindrical parts used in energy generation equipments to suffer damage due to thermal shock. Cracks originated in this process are usually shallow and located nearby stress concentration area. If the thermal shock happens to occur during the start up process, cracks may show at the outer face, but if the part is suddenly depressurized or receive cold fluid, cracks are bound to show up at cylinder's inner face. The resulting stresses (due to internal pressure and temperature gradients) will determine if the cracks will propagate or not. Positive net stresses may act catastrophically over damaged pressure vessels. This work explores the described situation and proposes controlling crack propagation by means of altering temperature difference between cylinder’s walls. Weight functions approach is used to expresses acting stress intensity factors.