核级管道系统热应力分析方法研究及试验验证

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

介绍了热应力分析的有限元基本思想,讨论了基于ANSYS的热应力分析方法,为保证计算精度及计算效率,试验系统的总体分析模型采用管壳单元,对应力较大位置处的典型管件(如直管或弯管)建立局部精细化体模型进行典型测点的热应力计算值;开展核级管道总体结构力学模型合理性研究,以试验振动频率与模态结果为判据,对仿真模型关键参数迭代分析,提高了仿真分析模型与真实结构的吻合度;最后开展典型管道系统热应力计算及对应结构热应力试验测量,分析计算结果与试验结果偏差,评价模型关键参数修正效果及分析模型的合理性。结果表明,典型系统热应力计算值与试验值最大偏差为4.63%,吻合良好,验证了热应力建模及模型修正方法、热应力分析方法的有效性。

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.