基于疲劳裂纹特征尺寸的TC4焊接接头疲劳强度预测模型
Fatigue strength prediction model of TC4 welded joint based on fatigue crack feature size
陈雨 1杨溥 1孔建行 1于欢 1刘杰 1邓海龙2
作者信息
- 1. 内蒙古工业大学机械工程学院,内蒙古 呼和浩特 010051
- 2. 内蒙古工业大学机械工程学院,内蒙古 呼和浩特 010051;内蒙古自治区先进制造技术重点实验室,内蒙古 呼和浩特 010051
- 折叠
摘要
文章旨在构建TC4 焊接接头的超高周疲劳强度预测模型.在应力比为-1 的情况下对TC4 焊接接头展开超高周疲劳试验.结果表明,TC4 焊接接头的S-N特性呈连续下降的趋势,P-S-N曲线的拟合效果很好.通过扫描电镜对断口表面裂纹形貌的观测,疲劳寿命低于 1×106 循环周次时,其疲劳失效形式既有表面失效也有内部失效;疲劳寿命高于 1×106 循环周次时,其疲劳失效形式主要为内部失效.最后,虑及失效机理,构建了基于内部缺陷尺寸、细晶粒区尺寸的TC4 焊接接头疲劳强度预测模型,其预测疲劳强度误差更小,预测结果更精确.
Abstract
This paper aims to construct a prediction model of ultrahigh cycle fatigue strength of TC4 welded joints.The ultra-high cycle fatigue test of TC4 welded joint is carried out under the stress ratio of-1,and the results show that the S-N characteristics of TC4 welded joint show a continuous decreasing trend,and the fitting effect of P-S-N curve is good.According to the observation of the crack morphology on the surface of the fracture by scanning electron microscope,when the fatigue life is less than 1×106 cycles,the fatigue failure forms are both surface failure and internal failure.When the fatigue life is higher than 1×106 cycles,the fatigue failure mode is mainly internal failure.Finally,based on the failure mechanism,the fatigue strength prediction model of TC4 welded joint was established,taking into account the size of internal defects and fine grain region.Compared with the fatigue strength predicted by other models,the prediction error of the new model is the least,and the prediction result is more accurate.
关键词
TC4焊接接头/超高周疲劳/裂纹特征尺寸/疲劳强度预测Key words
TC4 welded joint/ultra high cycle fatigue/crack characteristic size/fatigue strength引用本文复制引用
基金项目
内蒙古自治区自然科学基金(2021LHMS05009)
内蒙古自治区自然科学基金(2022MS05014)
内蒙古自治区直属高校基本科研业务费项目(JY20220233)
内蒙古自治区高等教育研究项目(NJZY21306)
内蒙古工业大学科学研究项目(ZY202005)
出版年
2024
NETL
NSTL
万方数据