THE THERMAL AND MECHANICAL BEHAVIOR OF A JOINT PIPE SYSTEM CALCULATED BY FINITE ELEMENT METHOD

摘要

This paper investigated numerically the thermal and mechanical behavior of joint pipe system. The joint pipe system studied was subjected to the internal pressure and the thermal stress that came from the instantaneous temperature variation. A 3D finite element model is established to simulate the instantaneous process of pressurized thermal shock (PTS) in nuclear power station, however, it is also available to other pipe systems under thermome-chanical load condition. The stress produced by thermal shock is much higher than that produced by pressure variation. The highest stress is situated at the joint of the injection pipe and the pressure vessel, and local plastic areas consequently occur in these places. The coupling effects of mechanical and thermal stresses have been analyzed and the influences of combined stress on the pressure vessel strength have been evaluated.