作者：张国胜, 张志强, 刘艳芳, 高素梅

作者单位：1. 天津工程机械研究院再制造与工艺材料研究所, 天津 300409;
2. 天津职业大学, 天津 300410

关键词：疲劳; 裂纹扩展; 剩余寿命评估; 声发射检测;

摘要：

以高频三点弯曲疲劳试验机为平台,进行42CrMo钢疲劳裂纹扩展试验研究,通过建立裂纹扩展剩余寿命评估模型,实现对存在裂纹的工程机械零部件剩余寿命的评估。采用显微成像测试系统实时采集并测量疲劳扩展裂纹,使用声发射系统监测整个疲劳裂纹扩展过程。结果表明:声发射幅值、能量等特征参数可以实时反应疲劳裂纹萌生、稳定扩展和失稳扩展等各个损伤阶段,并在疲劳断裂时产生急剧的突变;裂纹扩展速率的对数值与应力强度因子幅的对数值具有较高的线性相关性,建立了不同应力工况条件下裂纹扩展剩余寿命评估模型,以双排链轮轴为例进行裂纹扩展剩余寿命评估;随着疲劳应力的增加,裂纹扩展剩余寿命减小。

Residual life evaluation of fatigue crack growth of 42CrMo steel

ZHANG Guo-sheng, ZHANG Zhi-qiang, LIU Yan-fang, GAO Su-mei

1. Tianjin Research Institute of Construction Machinery, Institute of Remanufacture and Processing Material, Tianjin 300409, China;
2. Tianjin Vocational Institute, Tianjin 300410, China

Abstract: Fatigue crack growth of 42CrMo steel was experimentally researched on high frequency three-point bending fatigue tester. In order to complete life evaluation of construction machinery parts,the residual life evaluation model of crack growth was established. Fatigue growth crack was collected and measured by the microscopic imaging testing system. The process of fatigue crack growth was monitored by the acoustic emission system. The results show that fatigue damage at all stages,i.e.,crack initiation,stable growth and unstable growth,could be real-time reflected by the acoustic emission characteristic parameters, such as amplitude and energy. And the acoustic emission characteristic parameters generated a sharp rise at the stage of fatigue fracture. It was higher linear correlation between the logarithm value of crack growth rate and that of stress intensity factor range. Residual life evaluation model of crack growth was established under different stress conditions. Take double chain wheel for example,the residual life evaluation of crack growth was finished. With the increase of fatigue stress,the residual life of crack growth was reduced.

Keywords: fatigue; crack growth; residual life evaluation; acoustic emission monitoring

2014, 40(6): 127-132  收稿日期: 2014-1-9;收到修改稿日期: 2014-3-4

基金项目: "十二五"国家科技支撑计划(2011BAF11B08)

作者简介: 张国胜(1963-),男,副总工程师,主要从事工程机械、表面工程、装备再制造等研究。

参考文献

[1] 徐东. 球轴承疲劳剩余寿命分析与预测方法研究[D]. 北京:国防科技大学,2011.
[2] Mohanty J R,Verma B B,RayP K. Prediction of fatigue crack growth and residual life using an exponential model:Part I (constant amplitude loading)[J]. International Journal of Fatigue,2009,31(3):418-424.
[3] Paris P C,Erdogan F. A critical analysis of crack propagation laws[J]. Trans ASME,J Basic Eng,1963(58):528-534.
[4] Miner M A. Cumulative damage in fatigue[J]. Journal of Applied Mechanics,1945,12(3):159-164.
[5] 高镇同,熊峻江. 疲劳/断裂可靠性研究现状与展望[J]. 机械强度,1995,17(3):61-79.
[6] Liu Y M,Mahadevan S. Probabilistic fatigue life prediction using an equivalent initial flaw size distribution[J]. International Journal of Fatigue,2009,31(3):476-487.
[7] Luo R K, Gabbitas B L, Brickle B V. Fatigue life Evaluation of a railway vehicle bogie using an integrated dynamic simulation[J]. Proc Insn Mech Engrs, 1994,208(2):23-132.
[8] Luo R K,Gabbitas B L,Brickle B V. Fatigue damage evaluation for a railway vehicle bogie using appropriate sampling frequencies[J]. Vehicle System Dynamics, 1998,29(1):404-415.
[9] 王成国,孟广伟,原亮明. 新型高速客车构架的疲劳寿命数值仿真分析[J]. 中国铁道科学,2001,58(3):32-35.
[10] 邓聚龙. 灰色控制系统[J]. 华中工学院学报,1982,10(3):9-18.
[11] 石常亮. 面向再制造铁磁性构件损伤程度的磁记忆/超声综合无损评估[D]. 哈尔滨:哈尔滨工业大学,2011:46-104.
[12] 耿荣生. 声发射技术发展现状-学会成立20周年回顾[J]. 无损检测,1998,20(6):151-154.
[13] Yu J G,Ziehl P,Zárate B,et al. Prediction of fatigue crack growth in steel bridge components using acoustic emission[J]. Journal of Constructional Steel Research,2011,67(8):1254-1260.
[14] Piao Z Y,Xu B S,Wang H D,et al. Investigation of fatigue prediction of Fe-Cr alloy coatings under rolling contact based on acoustic emission technique[J]. Applied Surface Science,2011,257(7):2581-2586.