Torsional vibration of a shaft with a circumferential crack

✍ Scribed by Andrew Dimarogonas; George Massouros

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 433 KB
• Volume: 15
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(81)90069-2

✦ Synopsis

The influence of a circumferential crack upon the torsional dynamic behavior of a shaft is studied. introduction of such a crack results in lower torsional natural frequencies due to the added flexibility.

The strain energy release function is related to the compliance of the cracked shaft, that is to the local flexibility due to the introduction of the crack. This function is related to the stress intensity factor which for torsion of a shaft with a circumferential crack has a known expression. As a result, the local flexibility of the shaft due to the presence of the crack has been computed. This result can be further utilized to yield the dynamic response of a shaft with complex geometry.

The torsional natural frequency is expected to decrease with increasing crack depth. To establish such function, a contjnuous shaft with a circumferential crack was analyzed. The fundamental natural frequency showed strong dependence on the crack depth. This dependence is smaller as the order of the frequency increases. Experimental results are in close agreement with analysis.

The results show that the change in dynamic response due to the crack is high enough to allow the detection of the crack and estimation of its location or magnitude.