压水堆燃料组件压紧板弹簧刚度简化模型研究

Study on Simplified Stiffness Model of PWR Fuel Assembly Hold-down Spring

刚度是压水堆燃料组件压紧板弹簧的重要设计参数,通常由试验获取。开展刚度模型研究,合理预测板弹簧的服役性能,是反应堆燃料组件设计验证及安全评价的重点内容之一。本文基于悬臂梁小挠度变形理论,建立了变厚度板弹簧刚度计算的简化模型,并研究了主要参数对板弹簧刚度的影响。结果表明:板弹簧的刚度与宽度及杨氏模量呈线性关系变化,与根部厚度呈三次方关系变化;板弹簧刚度随长度减小而增加,随高度增加而增加,随端部厚度与根部厚度之比近似线性增加。本文建立的分析模型对压水堆燃料组件板弹簧性能评估和优化设计具有参考意义。

Stiffness is a crucial design parameter for Pressure Water Reactor(PWR)fuel assembly hold-down springs,which is currently obtained by experiment.It is one of the key contents of nuclear fuel design verification and safety evaluation to study the stiffness model and reasonably predict the service performance of leaf spring.In this study,bases on the deformation theory of cantilever,a simplified model for stiffness calculation of spring leaf with variable thickness was proposed.Parametric studies of stiffness were carried out.The results show that the stiffness of hold-down spring leaf varies linearly with the width,Young’s Modulus,and approximately the thickness ratio of end to root,while has a three cubed relationship with the root thickness.The spring stiffness increases along with the increase of spring height,and decreases with the increase of spring length.The analysis model established in this paper has reference significance for performance evaluation and optimization design of PWR fuel assembly leaf spring.