Study and Experimental Verification of Thermal Stress Analysis Method for Nuclear Primary Piping System

The principle of finite element method is briefly introduced in this paper. Then the methods of thermal stress analysis using the finite element analysis program ANSYS are introduced, in order to guarantee the calculation accuracy and computational efficiency, and the shell-pipe model for the overall test system and the body element part model for the larger stress location of the straight or curved pipe fitting are used in the thermal stress analysis. In order to get a reasonable mechanical analysis model of the overall structure of the system, it is necessary to modify the influence factors till the results satisfy the test vibration frequency and the modal results. It will improve the compliance between the simulation model and the real structure. Finally, the thermal stress calculation and test verification of the typical pipe are carried out, and the deviation between the calculated results and the test results is analyzed. The correction effect of the key parameters of the model and the rationality of the analysis model are evaluated. The results show that the maximum deviation between the calculated value of the thermal stress and the test value of the typical primary loop system is 4. 63%, which is in good agreement. The thermal stress modeling is verified, and the key parameter correction method and the thermal stress analysis method are effective. (authors)