高温气冷堆压力容器开孔形状优化的边界元法研究

Research on Shape Optimization of RPV Opening of High Temperature Gas-Cooled Reactor Using Boundary Element Method

大开孔应力集中是高温气冷堆反应堆压力容器结构完整性分析的重点关注的课题之一。应力集中水平取决于开孔形状的设计。本文将三维边界元法用于高温气冷堆核电站示范工程反应堆压力容器的大开孔形状优化研究。边界元法只需在边界划分网格,在开孔形状优化过程中仅移动边界网格,避免了体积网格畸变问题。采用基于自适应生长的形状优化算法,通过应力集中区域沿法线方向生长有效降低应力。数值算例表明,该算法可方便得到具备低应力水平的优化开孔形状。

Stress concentration is one of the fields that attract major concerns in the structure integrity analysis of the reactor pressure vessel （RPV） of the High Temperature Gas-cooled Reactor （HTGR）. The concentrated stresses depend on the opening shape. In this paper, the boundary element method （BEM） is used for shape optimization of the HTR-PM RPV large opening. The BEM requires only boundary meshing and thus only boundary meshes move during the opening shape optimization process, avoiding the issue of volume mesh distortion. By using the shape optimization algorithm based on adaptive growth, stresses can be effectively reduced with normal growth happens in the areas of stress concentrations. Numerical tests show that optimized opening shape with low stresses can be readily obtained using the presented method.