预循环应力对材料断裂力学性能“锻炼”效应的影响  

‘Coaxing effect'of prior cycling stress on material fracture mechanics performance

作　　者：张啸尘[1,2] 谢里阳[1,2] 张瑞金[1,2] 孟维迎[1,2] 李铭[1,2] 胡杰鑫 

机构地区：[1]东北大学机械工程与自动化学院现代设计与分析研究所,沈阳110819 [2]东北大学航空动力学装备振动及控制教育部重点实验室,沈阳110819

出　　处：《航空学报》2016年第10期3074-3082,共9页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(51335003);辽宁重大装备制造协同创新中心资助~~

摘　　要：对服役多年的高速列车用7N01铝合金材料进行疲劳裂纹扩展速率试验,其对数坐标系中的疲劳裂纹扩展速率da/d N与应力强度因子ΔK的关系呈折线形式。与未服役材料对比,在裂纹扩展初期阶段,裂纹扩展速率降低。选取两种原始铝合金材料进行107次预循环应力作用后的疲劳裂纹扩展速率试验,研究低于疲劳极限的预循环应力对材料断裂力学性能的影响。结果表明:经预循环应力作用的材料,其da/d N与ΔK的关系曲线在裂纹扩展初期(对应于低应力强度因子阶段)均出现折转现象。对试验数据的回归分析表明:预循环应力的作用使得材料的断裂力学性能有所提高,预循环应力对材料产生"锻炼"效应。The fatigue crack growth rate tests were carried out using aluminum alloy materials served in high-speed train for years,and the relationship of fatigue crack growth rate da/dN and the stress intensity factorΔK was shown in a broken form in logarithmic coordinates.Compared with the non-service material,the crack growth rate decreases at the initial stage.Aiming at this phenomenon,the aluminum alloy materials were applied here to investigate the behavior of fatigue crack growth under 107 prior cycling stress.The influence of prior cycling stress under fatigue limit on the material fracture mechanics performance was studied in details.The results show that the curves of da/dNvsΔKof prior cycling stress materials present a broken form in the lowΔK period.The regression analyses of the test data illustrate that the prior cycling stress plays a positive role in the fracture performance,and the prior cycling stress has‘coaxing effect＇on the fatigue crack of materials.

关 键 词：疲劳裂纹扩展速率 预循环应力 服役材料 断裂力学性能 “锻炼”效应 

分 类 号：V252[一般工业技术—材料科学与工程]