摘要
用激光衍射谱谱面光强比Ｋ和超声速Ｃ的变化定义损伤变量Ｄ（Ｋ）和Ｄ（Ｃ），对ＬＤＳ和４０ＣｒＮｉＭｏＡ材料进行了疲劳损伤检测．结果表明：Ｋ和Ｃ的变化对疲劳损伤是敏感的；根据Ｄ（Ｋ）或Ｄ（Ｃ）与循环次数Ｎ的关系曲线，可以确定材料疲劳损伤的程度并对其疲劳寿命进行估计．
Haworth et al made use of a physical quantity indirectly connected with suiface roughness of metal[1]. Different from Haworth the authors in this paper make use of a physical quantity directly connected with surface roughness of metal. It is intensity ratio K of Laser diffraction spectrum.Stigh used D(C), wbers C is ultrasonic velocity, in discussing plastic damage [4]. Now the authors apply D(C) to discussing fatigue damage.In this paper, in addition to D(C) the authors define another fatigue damage.paramdsr D(K). The authors make use of D(K) and D(C) in the analysis of fatigue damage of aluminum alloy LDS (corresponding approximately to ASTM 2014) and high strength steel 40CrNiMoA (corresponding approximately to ASTM 4340). Analysis of test results with D(K) and D(C) gives:(1) The curve relating N to D(K) can be divided into three.rcgions:decelerated, linear and aecelcrated.80～90% of fatigue life belong to the decelerated and linear regions.(2) D(C)=aNb. where a and b are constants determined by tests.(3) D(K) is more sensitive that D(C) to fatigue damage.(4) D(K)=A exp[B/D(C)]+d, wbers A.B and d are constants determined by testS,D(K) and D(C) possess clear physical meanings. As compared with Haworth[2] and Dai[1],the authors nced only simpler equipment,the measurements are more convenient,and data processing is faster.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1994年第1期129-134,共6页
Journal of Northwestern Polytechnical University
基金
国家航空科学基金
关键词
超声速
疲劳损伤
金属材料
激光
diffraction intensity ratio, ultrasonic velocity, damage variable fatigue damage
