Resonance controlled fatigue crack propagation in a beam under longitudinal vibrations

✍ Scribed by A. J. Dentsoras; A. D. Dimarogonas

• Publisher: Springer Netherlands
• Year: 1983
• Tongue: English
• Weight: 364 KB
• Volume: 23
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00020154

✦ Synopsis

Fatigue crack growth in resonating members of distributed mass is studied under conditions of dynamic interaction between crack growth and crack load. The crack propagation rate is related to the stress intensity factor range by way of the well known power law. The depth of the crack determines the local flexibility due to crack which in turn influences the dynamic response of the system under an external force with constant amplitude and frequency. The propagating crack introduces additional flexibility to the continuous system which results in gradual shifting away of the resonance which results in smaller loading of the cracked section. This reduces, in general, the growth rate and brings eventually the system to a value of crack propagation rate below a conventional threshold rate which can be interpreted as dynamic crack arrest. It is important from an engineering standpoint to know the total crack growth at that time which determines the component structural integrity.

Material damping is introduced through the use of complex modulus of elasticity and determines absolutely the crack growth rate in resonance, assuming that material damping is the dominant damping mechanism of the system.