Fatigue crack growth under random loading

✍ Scribed by H. Alawi; M. Shaban

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 820 KB
• Volume: 32
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(89)90181-1

✦ Synopsis

An experimental technique is developed whereby a personal computer is used to control a hydraulic servo-pulser testing machine and generate random loads for loading a fracture specimen. Thus giving a control over random load generation and hence random load history. This allows for the generation of load histories following different distribution families and parameters and subjecting fatigue crack growth specimen to them. Different steels are used to study fatigue crack growth behaviour under random loading. These are AISI 1018, AISI 4340 and stainless steel 17/7 PH. Test results for these steels are reported here. The effect of frequency on steel AISI 1018 under random loads is also studied and presented. The phenomenon of fatigue crack growth retardation and acceleration are clearly exhibited in this study. Plot of fatigue crack length vs number of cycles is observed to be random in path as cyclic loading progresses. Fatigue life is also found to be random. These phenomena occur for loads following a fixed distributed family and parameters.