外物损伤对不锈钢疲劳强度的影响

发布时间：2018-04-05 19:20

本文选题：外物损伤　切入点：疲劳强度　出处：《航空动力学报》2016年07期

【摘要】：基于空气炮法,针对不锈钢平板试样开展了外物损伤(FOD)模拟试验,使用三维体式显微镜观测了损伤的宏观特征,并用扫描电子显微镜观测了损伤的微观特征,模拟外物损伤具有挤压变形、材料的剪切丢失、塑性变形等宏观特征和微小裂纹、塑性变形、微小缺口、片层结构等微观特征.采用步进法对FOD试样进行了高周疲劳试验,试验结果表明FOD使试样的疲劳强度相对未损伤试样下降超过14%,并且随损伤尺寸的增大,试样的疲劳强度基本呈降低的趋势.疲劳源区多为损伤处的微小缺口或微小裂纹,说明FOD为疲劳裂纹的萌生和扩展提供了有利条件.
[Abstract]:Based on the air gun method, an external object damage simulation test was carried out for stainless steel plate specimens. The macroscopic damage characteristics were observed by using three-dimensional microscope, and the microscopic damage characteristics were observed by scanning electron microscope (SEM).The damage of simulated external objects is characterized by extrusion deformation, shearing loss of materials, plastic deformation and micro cracks, plastic deformation, tiny notches, lamellar structures and so on.The high cycle fatigue test of FOD specimen was carried out by step method. The results showed that the fatigue strength of FOD sample decreased by more than 14% compared with the undamaged specimen, and the fatigue strength of the specimen decreased with the increase of damage size.The fatigue source region is mostly a tiny notch or crack in the damage area, which indicates that FOD provides favorable conditions for the initiation and propagation of fatigue cracks.
【作者单位】：南京航空航天大学能源与动力学院江苏省航空动力系统重点实验室;先进航空发动机协同创新中心;
【分类号】：V231.91

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