摘要
针对当前汽轮机转子低周疲劳损伤分析存在较大误差的问题,引入了非线性连续损伤力学理论,并结合多轴疲劳损伤的临界面原理,建立了多轴非线性连续损伤累积模型。基于该模型,结合某型船用汽轮机转子典型工况下的瞬态温度场和热应力场的弹塑性有限元分析结果,对复杂应力引起的转子低周疲劳损伤进行分析,并与等效应变法的寿命预测模型和线性损伤累积模型进行了比较。结果表明:基于临界面法的非线性连续损伤累积模型,不仅考虑了多轴复杂应力应变的大小、方向和加载的附加强化效应的影响,而且正确地反映了转子低周疲劳损伤的非线性累积过程,其分析结果更接近于工程实际。
For the problem that there is large error in the low cycle fatigue damage analysis of turbine rotor, according to introducing a nonlinear continuous damage mechanics model, and on the basis of the critical plane principle for multiaxial fatigue damage ,a nonlinear multiaxial fatigue damage cumulative model was proposed. The model is applied to analyzing the low cycle fatigue damage and life of turbine rotor caused by complex stress by combining the results that the transient temperature fields and thermal stress field of a marine turbine rotor is calculated by firdte element method under typical load, and compared with life prediction model for equivalent strain and linear cumulative damage model. The results of the analysis show that not only the size and direction of multiaxial complex stress - strain and additional strengthening effect are taken into account, but also the nonlinear accumulation process of low cycle fatigue damage is described correctly in the nonlinear fatigue damage cumulative model based on a critical plane approach. Therefore, the results from nonlinear continuous damage mechanics model satisfy the applications of practical engineering.
出处
《汽轮机技术》
北大核心
2011年第2期110-114,共5页
Turbine Technology
基金
武器装备预研基金项目资助(9140A27050106JB11)
2006新世纪优秀人才计划资助
关键词
汽轮机转子
多轴疲劳
临界面
寿命预测
损伤累积
turbine rotor
multiaxial fatigue
critical plane
life prediction
cumulative damage
