基于材料细观特性的TC4钛合金疲劳裂纹萌生寿命仿真  

SIMULATION OF FATIGUE CRACK INITIATION LIFE OF TC4 TITANIUM ALLOY BASED ON ITS MESOSCOPIC PROPERTIES

作　　者：蒋泽 许希武[1] 郭树祥[1] 吴斌[2] 戚岩[2] JIANG Ze;XU XiWu;GUO ShuXiang;WU Bin;QI Yan(State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;AVIC Shenyang Aircraft Design&Research Institute,Shenyang 110000,China)

机构地区：[1]南京航空航天大学机械结构力学及控制国家重点实验室,南京210016 [2]沈阳飞机设计研究所,沈阳110000

出　　处：《机械强度》2021年第2期425-433,共9页Journal of Mechanical Strength

基　　金：民机专项科研(MJ-2015-F-027);中央高校基本科研业务费专项资金(NS2016003)资助。

摘　　要：建立了TC4钛合金材料的疲劳裂纹萌生寿命的预测模型,并通过试验验证了此模型在预测TC4钛合金材料疲劳裂纹萌生寿命时的可行性。基于裂纹萌生的细观位错模型,采用Tanaka-Mura的开裂寿命公式,考虑了表面粗糙度,提出了分析TC4钛合金材料疲劳裂纹萌生的有限元模型,并通过实验验证仿真模型的有效性。结果表明:模型裂纹萌生形式在不同载荷水平下存在差异,高应力水平状态下,模型除了主裂纹的萌生扩展还伴有大量独立微裂纹,裂纹密度大,而在低应力水平状态下,模型存在少量独立微裂纹,裂纹密度小。This paper presents that the prediction model of fatigue crack initiation life of TC4 titanium alloy,and the feasibility of the model in predicting the fatigue crack initiation life of TC4 titanium alloy is verified by experiments. Based on the micro dislocation model of crack initiation and Tanaka mura’s formula of crack life,considering the surface roughness,a finite element model for fatigue crack initiation of TC4 titanium alloy is proposed,and the validity of the simulation model is verified by experiments. The results show that the crack initiation forms of the model are different under different load levels. At high stress levels,the model has a large number of independent microcracks in addition to the initiation and propagation of the main cracks,with a large crack density. At low stress levels,the model has a small number of independent microcracks,with a small crack density.

关 键 词：钛合金 疲劳寿命 裂纹萌生 仿真模型 细观力学 

分 类 号：TB31[一般工业技术—材料科学与工程]