摘要
针对热端部件因温度和应力分布不均而导致的低周疲劳寿命难以准确预测的难题,本文提出了一种考虑多参数影响的低周疲劳寿命预测新模型,该模型创新性地引入总应变幅值、弹性应变比、最大主应力及温度等关键影响参数.首先,基于退化模型,对某镍基高温合金多温度点(RT-650℃)的低周疲劳寿命进行预测分析,结果表明,在单一温度条件下,相较于传统的Manson-Coffin模型和SWT(Smith-Watson-Topper)模型,本模型预测结果除650℃温度点一个离散点落在±1.5和±2倍分散带之间,其余数据点均严格收敛于±1.5分散带之内,预测精度显著提升.其次,通过全局参数优化算法进行多温度场数据融合,结合留一交叉验证法(Leave-One-Out CrossValidation, LOOCV)和泛化能力测试,验证了模型具有91.9%预测点位于±2倍分散带内的稳健性,且对非试验温度工况及多类工程合金材料展现优异外推能力和适应能力.最终工程验证表明,该模型应用于某小型燃气轮机涡轮盘低周疲劳寿命评估时,预测结果具有良好的合理性,为高温部件低周疲劳寿命评估提供了新的理论方法.
Aiming at the challenge of accurately predicting low-cycle fatigue(LCF)life caused by uneven temperature and stress distributions in hot-end components,this paper proposes a novel multi-parameter-influenced LCF life prediction model.This model innovatively incorporates critical parameters including total strain amplitude,elastic strain ratio,maximum principal stress,and temperature.Firstly,based on the degradation model,LCF life prediction analysis was conducted for a nickel-based superalloy under multiple temperature conditions(RT-650 C).Results demonstrate that under single-temperature conditions,compared with the traditional Manson-Coffin model and SWT(Smith-Watson-Topper)model,the proposed model achieves significant accuracy improvement-with only one outlier at 650°C falling between±1.5 and±2 scatter bands,while all other data points strictly converge within the±1.5 scatter band.Secondly,through global parameter optimization algorithm for multi-temperature field data fusion,combined with leave-one-out cross-validation(LOOCV)and generalization capability tests,the model exhibits robust performance with 91.9%of predicted points located within±2 scatter bands.It also demonstrates excellent extrapolation capability for non-tested temperature conditions and adaptability to various engineering alloy materials.Final engineering validation shows good rationality of the results when applying this model to LCF life assessment of a small gas turbine turbine disk,providing a new theoretical methodology for high-temperature component LCF life evaluation.
作者
邢冬燕
文阳阳
高闯
XING Dongyan;WEN Yangyang;GAO Chuang(Technical Centre,Helan Turbine Co.,Ltd.,Shanghai 201815,China;Advanced Energy Systems and Equipment Research Center,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China)
出处
《力学季刊》
北大核心
2025年第4期934-947,共14页
Chinese Quarterly of Mechanics
基金
中国科学院重点部署项目(E3241K1)。
