摘要
针对试样内部缺陷影响疲劳寿命问题,研究钛合金TC17激光粉末增材试样高频振动应力场。构建了TC17激光粉末增材试样高频(1100 Hz)振动有限元模型,包括含内部气孔及无气孔模型。采用小孔法测定了试样特征点应力值,确定了4.5 mm位移载荷下有限元模型的可靠性。应力集中位置在过渡弧上端的两侧表面,在板厚方向由外及内应力集中逐渐缓解,中心区域米赛斯应力为载荷1/11;随着气孔直径增加以及气孔与表面的距离减小,气孔处米赛斯应力逐渐增加,甚至超过表面;建立了对应位置的临界气孔尺寸关系图,并对疲劳裂纹源位置进行了预测。
The influence of internal defects on fatigue life was addressed through the investigation of the high-frequency vibration stress field in titanium alloy TC17 specimens fabricated by laser powder additive manufacturing.Finite element models of TC17 laser powder additive specimens under high-frequency(1100 Hz)vibration were constructed,including models both with and without internal porosity.The stress values at characteristic points of the specimens were measured using the small hole method,and the reliability of the finite element model under a displacement load of 4.5 mm was confirmed.Stress concentration was identified on both surface sides at the upper end of the transition arc,with stress concentration gradually alleviated from the outer to the inner part along the thickness direction,and the von Mises stress in the central region was found to be one-eleventh of the load.As the diameter of the porosity was increased and the distance between the porosity and the surface was decreased,the von Mises stress at the porosity was observed to gradually increase,even surpassing that on the surface.A relationship diagram of critical porosity size for corresponding locations was established,and the location of fatigue crack initiation was predicted.
作者
李永奎
武朋达
陈振林
王海涛
鲁志伟
程明聪
陈家伟
LI Yongkui;WU Pengda;CHEN Zhenlin;WANG Haitao;LU Zhiwei;CHENG Mingcong;CHEN Jiawei(College of Mechanical Engineering,Shenyang University,Shenyang 110044,China;AECC Shenyang Aero-Engine Co.,Ltd,Shenyang 110862,China;Institute of Corrosion Science and Technology,Guangzhou 510530,China)
出处
《沈阳大学学报(自然科学版)》
2025年第2期93-98,F0002,F0003,共8页
Journal of Shenyang University:Natural Science
关键词
TC17钛合金
激光粉末增材
高频振动应力场
内部气孔
有限元模拟
TC17 titanium alloy
laser powder additive manufacturing
high-frequency vibration stress field
internal porosity
finite element simulation
