摘要
热棘轮分析是核电管道设计中重要的分析内容,压水堆(PWR)核电站一般基于Bree图对管道热棘轮效应进行规定,但当管道受到很大的热瞬态载荷时往往不能够满足此要求,需要进一步对管道棘轮安定性进一步分析。采用Chaboche非线性随动强化模型对PWR核电站中不能够满足RCC-M规范B3653.7章节的稳压器喷淋管线上的三通进行弹塑性分析,通过对RCC-M规范要求、模型简化方法、本构模型假定、压力和瞬态热载荷循环加载等方面的研究,利用ANSYS11.0软件对三通的热棘轮变形进行评定。分析结果表明,在345℃→20℃和10℃→240℃两个瞬态温度变化后膜应力出现峰值;在压力和瞬态热载荷共同作用下,膜应力最大位置在模型主管和支管的过渡位置。通过进一步对模型在10次循环载荷后的累积渐进性变形进行分析,结果表明,分析对象的塑性变形速度随着循环加载不断降低,具有循环硬化特征。模型的尺寸变形均远远小于3.5%,10次循环后的热棘轮变形对结构的塑性安定性影响很小,满足RCC-M规范对渐进性变形的要求。
Thermal ratcheting analysis is an important part of nuclear power station pipe design, which is prescribed based on the Bree diagram in PWR power station. But usually it can＇t be meet when the pipe subjected large thermal shock and need to be analysis further. The tee branch at the pressurizer spray line of PWR station which can＇t meet the B3653.7 chapter of RCC - M code was made a elastic-plasticity a- nalysis based on Chaboche modal. It was investigated on the modal simplified method, constitutive model postulated, pressure and thermal transient load application, and also thermal ratcheting deformation of the tee branch was evaluated using ANSYS11.0. It is demonstrated that the membrane stress reach the ex- treme value just after 345 ℃→20 ℃ and 10 ℃→240 ℃ temperature variation;the most severe stress po- sition is at the transition area between the main pipe and branch subjected pressure and thermal load sim- ultaneously. The modal cumulative deformation subjected 10 times cycle load was analyzed. It was repre- sented that the plastic deformation velocity decrease and the material have the cyclic hardening property. The modal size deformation was far less than 3.5 %, so the influence of thermal ratcheting deformation on the structure plastic stability was small which meet the cumulated deformation requisition of RCC - M code.
出处
《压力容器》
2015年第10期48-53,60,共7页
Pressure Vessel Technology
