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1979年5年25日,美国航空公司一架庞大的DC—10客机,从芝加哥国际机场刚起飞不久,飞机的左发动机从机翼上掉下来,飞机失去平衡下栽失事,机上271人全部遇难。事后经过调查方知,其原因是固定发动机吊舱的螺栓因疲劳而断裂造成飞机失事。近年来,在长期的实践中,人们发现,零件会在远低于材料抗拉强度的交变应力作用下,工作一段时间就发生破坏,这种破坏被称为疲劳破坏。因这种破坏在事故发生前不产生明显的塑性变形,所以一般不易被发现,也很难预防,危害极大。多年来,各国科学家为此做了大量试验研究,对金属材料的疲劳问题才有了一定的认识。
On the 25th of 1979, American Airlines’ huge DC-10 airliner took off just shortly after taking off from Chicago International Airport. The left engine of the aircraft fell from the wing and the plane lost its balance. All of the 271 people were killed . After investigation, the cause of the accident was that the bolts that fixed the engine pods broke due to fatigue and caused the plane crashes. In recent years, in the long-term practice, it has been found that the parts will break down when working for a period of time under the alternating stress much lower than the tensile strength of the material. Such damage is called fatigue destruction. Because of this damage before the accident did not produce significant plastic deformation, it is generally not easy to find, it is difficult to prevent, endangering great. Over the years, scientists from all over the world have done a great deal of experimental research, and have a certain understanding of the fatigue problem of metal materials.