低载强化后汽车结构件疲劳裂纹扩展速度研究  

Fatigue Crack Propagation Rate of Automobile Structures after Strengthening Under Low Amplitude Load

作　　者：卢曦[1] 郑松林[1] 

机构地区：[1]上海理工大学机械工程学院,上海200093

出　　处：《机械科学与技术》2006年第9期1117-1119,共3页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(50375101);上海汽车工业科技发展基金项目(0329)资助

摘　　要：为了从微观上揭示汽车结构件经过低载强化后疲劳强度和疲劳寿命提高的原因和机理,本文利用扫描电镜,对某汽车前轴低载强化前后试样断口的疲劳裂纹扩展速度进行了对比研究。研究结果表明,经过低载强化后的汽车结构件断口试样,其贝纹线的增长趋势减弱,疲劳辉度间距变小。这些微观变化有效地延缓了疲劳裂纹萌生,降低了疲劳裂纹扩展速率,使汽车结构件的疲劳强度和疲劳寿命都得到提高。To demonstrate from a micro point of view the reasons why the fatigue strength and fatigue life increase after automobile structures are strengthened under low amplitude load, the paper used a scan electronic microscopy to conduct a comparative study of the fatigue crack and striation propagation rate of an automobile＇s front axle before and after the fracture specimen of the automibile structures were strengthened under low amplitude load. The study results show that after the fracture specimen were strengthened, fatigue crack initiation and propagation rate slowed down because their beach mark increase trend was weakened and the fatigue striation interval became smaller, thus increasing the fatigue strength and fatigue life of the automobile structures.

关 键 词：疲劳裂纹 扩展速度 低载强化 汽车结构件 

分 类 号：U463.3[机械工程—车辆工程]