双金属定位格架静态屈曲行为数值模拟研究

周明; 肖忠; 任全耀; 秦勉; 何瑞; 蒲曾坪; 李正阳

doi:10.13832/j.jnpe.2024.050031

双金属定位格架静态屈曲行为数值模拟研究

doi: 10.13832/j.jnpe.2024.050031

中国核动力研究设计院先进核能技术全国重点实验室，成都，610213

基金项目: 国家重点研发计划（2022YFB1902400）；四川省科技计划资助（2024YFHZ0036）；四川省科技创新创业苗子工程（2022JDRC0099）；中核集团青年科技创新团队项目；中核集团青年英才项目

详细信息

作者简介:
周　明（2000—），男，硕士研究生，现主要从事反应堆核燃料设计研究，E-mail: 3143235309@qq.com

通讯作者:
肖　忠，E-mail: xz85903249@163.com

中图分类号: TL352
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- 文章访问数: 8
- HTML全文浏览量: 4
- PDF下载量: 1
- 被引次数: 0
出版历程
- 收稿日期: 2024-05-20
- 修回日期: 2024-07-06
- 网络出版日期: 2025-06-09
- 刊出日期: 2025-06-09

Numerical Simulation Study on Static Buckling Behavior of Bimetallic Spacer Grids

State Key Laboratory of Advanced Nuclear Energy Technology, Nuclear Power Institute of China, Chengdu, 610213, China

摘要

摘要: 定位格架的屈曲失稳行为会影响燃料组件的安全性，为掌握定位格架静态屈曲演化行为，本文基于有限元分析（FEA）方法建立双金属定位格架数值计算模型，通过计算结果与试验结果对比进行验证，并开展初始夹持力对格架强度影响研究。计算结果表明：数值模拟得到的临界屈曲载荷等结果与试验结果吻合良好；定位格架屈曲失稳的主要原因是邻近中心横排的部分条带产生塑性变形并扩大到整体；弹簧夹持力的减小对格架临界屈曲强度的影响较小，但对屈曲后的响应影响较大。本文建立的数值分析方法能够用于双金属定位格架静态临界屈曲载荷的预测，并为新型定位格架结构设计提供支持。
- 定位格架 /
- 有限元分析（FEA） /
- 临界屈曲载荷 /
- 初始夹持力
Abstract: The buckling behavior of spacer grids can seriously affect the safety of fuel assemblies. To understand the static buckling evolution characteristics of spacer grids, this study established a numerical model of bimetallic spacer grids using the Finite Element Analysis (FEA) method. The model was validated by comparing computational results with experimental data, and the influence of initial clamping force on grid strength was studied. The calculation results show that the critical buckling load obtained by numerical simulation is in good agreement with the experimental results. The primary cause of spacer grid buckling is the plastic deformation occurring in straps adjacent to the central transverse row, which subsequently propagates throughout the entire structure. The decrease of spring clamping force has little effects on the critical buckling strength of the spacer grid, but has great effects on the response after buckling. The numerical analysis method in this paper can predict the static critical buckling load of bimetallic spacer grid and provide support for the structural design of new spacer grid.
- Spacer grids /
- Finite element analysis (FEA) /
- Critical buckling load /
- Initial clamping force

HTML全文

图 1 燃料棒与夹持结构的接触状态

Figure 1. Contact Between Fuel Rods and Clamping Structure

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图 2 双金属定位格架结构模型

Figure 2. Structural Model of Bimetallic Spacer Grid

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图 3 延长条带方法模拟焊点

Figure 3. Extended Strap Method for Welding Spot Simulation

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图 4 格架屈曲计算边界条件

Figure 4. Boundary Conditions of Spacer Grid Bucking

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图 5 格架屈曲变形模式对比

Figure 5. Buckling Deformation Comparison between Test Result and FEA Result

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图 6 格架屈曲载荷-位移曲线

Figure 6. Load vs Displacement Curve of Grid Buckling

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图 7 格架计算结果（屈曲前）

Figure 7. Calculation Result of Grid (before Buckling)

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图 8 格架计算结果（屈曲临界）

Figure 8. Calculation Result of Grid (Critical Buckling)

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图 9 格架计算结果（屈曲后）

Figure 9. Calculation Result of Grid (after Buckling)

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图 10 不同方案计算结果载荷-位移曲线

Figure 10. Load vs Displacement Curve of Different Computational Schemes

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表 1 定位格架材料性能参数

Table 1. Material Properties of Spacer Grid

材料	密度 /（g·cm⁻³）	杨氏模量 /MPa	泊松比	屈服强度 /MPa
Zr-4	6560	98800	0.368	309
Inconel 718	8224	200100	0.293	1030

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表 2 计算结果与试验结果比较

Table 2. Comparison Between Test Results and FEA Results

格架静态屈曲结果	试验结果	计算结果	相对误差/%
临界静态屈曲载荷	22227 N	22877 N	2.9
总体平均静刚度	25662 N·mm⁻¹	22680 N·mm⁻¹	−8.3

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表 3 不同计算方案的临界屈曲载荷结果

Table 3. Critical Buckling Load Results of Different Computational Schemes

计算方案	初始夹持力/N	临界静态屈曲载荷/N	相对偏差/%
A	34.4	22877	0
B	26.8	22517	−1.6
C	21.6	22349	−2.3
D	16.5	22228	−2.8
E	11.7	22205	−2.9
F	7.0	22184	−3.0
G	3.5	22167	−3.1

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参考文献(11)

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