汽轮机膨胀节塑性变形损伤后结构力学性能分析

Mechanical Analysis of Steam Turbine Bellows after Plastic Deformation Damage

汽轮机金属膨胀节在制造、安装和运行阶段常发生塑性变形,影响其服役工况下达到设计膨胀补偿量和安全运行性能的要求。目前,核电厂关键设备主要设计参考规范(RCC-M、ASME规范第Ⅲ和ⅩⅢ卷等)正逐步发展为基于弹塑性理论的分析方法。针对某核电厂汽轮机膨胀节发生的塑性变形损伤,基于ASME规范和有限元软件ANSYS进行了膨胀节塑性变形损伤后结构力学性能分析,包含基于材料真实应力-应变数据的不同工况组合下塑性损伤分析及结构塑性损伤后疲劳寿命的校核。

During the manufacture,installation and operation process,plastic deformation damage often occurs in metal bellows expansion joints used in steam turbines,which will affect the expansion compensation and safe operation performance of the bellows.At present,the design codes for nuclear key equipment,such as RCC-M,ASME Code VolumeⅢandⅩⅢ,are gradually developing into the analysis method based on elastic-plastic theory.In this paper,mechanical analysis of the bellows expansion joint used in a nuclear power plant after plastic deformation damage was analyzed based on ASME code and using finite element software ANSYS,including plastic damage analysis under combination of different working conditions based on material real stress-strain data and fatigue life assessment after plastic damage.