EAST PF8线圈氦管结构分析和疲劳试验

 为解决EAST PF8线圈氦管在与导体连接的焊缝位置出现的泄漏问题，分析了该氦管的载荷及边界条件，给出了4种载荷组合工况。建立PF8氦管的有限元模型，对4种工况进行了静力学分析。计算结果表明，热载荷和螺管固定支撑板G11变形是焊缝失效的主要原因。在4.5K下对PF8氦管样件进行了疲劳试验，结果表明氦管疲劳寿命超过2×10⁵次，满足使用要求。对PF8氦管进行了修复，使氦管与螺管固定支撑板G11板脱开，避免了额外载荷的作用，满足EAST使用要求。

Structural analysis and fatigue test of helium inlet for EAST PF8 coil

 In order to solve the leakage of the helium inlet of East PF8 coil, four kinds of working conditions are established by analyzing the boundary conditions of the current structure of helium inlet. The finite element model of PF8 helium inlet is established, and the static analysis under the four working conditions is carried out. The calculation results show that thermal load and enforced displacement from the fixed support plate G11 are the main reasons of weld failure. The fatigue test of a full-size PF8 helium inlet sample has been carried out at 4.5K and with more than 2×10⁵ cycles, which satisfies EAST requirement. Through detaching the PF8 helium pipe from the G11 plate, the additional loads are completely avoided, and the repaired PF8 helium inlet has good structural performance and meets the requirements of EAST.