摘要
结合循环应力-应变曲线,获得N次载荷循环后船体缺口板累积塑性应变值,根据Neuber公式和Manson-Coffin方程建立了循环载荷下基于累积递增塑性破坏的船体缺口板低周疲劳裂纹萌生寿命的计算模型。通过有限元计算讨论了循环载荷的平均应力、应力幅值、应力比及尺寸效应的影响;所建立模型的计算结果与已有实验结果基本吻合;对合理预估单轴循环载荷下缺口板的低周疲劳裂纹萌生寿命以及提高船舶安全性有重要意义。
An analytical model for predicting low-cycle fatigue （LCF） crack-initiation life of ship notched plate is proposed on the basis of accumulative plastic damage in this paper. In this study, the focuses is to get the accumulative plastic strain after N time＇s constant amplitude cyclic loading, stress-strain curve at local zone and relevant plastic parameters of ship notched plate under cyclic loading. Combined with the Neuber＇s Formula, the Manson-Coffin Equation is implemented to predict the LCF crack-initiation life of ship notched plates. A numerical model is conducted to reflect the influences of plate size, the mean stress, stress amplitude and stress ratio on the LCF crack initiation of ship notched plate. It is concluded from the comparison that the results by presented calculation model correlate well with the existing experimental ones and are capable of predicting the low-cycle fatigue crack-initiation life of ship notched plate under cyclic axial in-plane loading.
出处
《船舶工程》
北大核心
2015年第9期76-80,85,共6页
Ship Engineering
基金
国家自然科学基金面上项目(51479153)
中央高校基本科研业务费专项资金资助项目(2015-yb-004)
关键词
船体缺口板
萌生寿命
累积塑性
低周疲劳
损伤累积理论
ship notched plate
crack-initiation life
accumulative plastic
low cycle fatigue
accumulative damage theory
