The definition of the load spectrum of the full-scale fatigue test of a new aircraft is a very delicate problem: among others, two important aspects are those concerning the maximum load and the minimum load range to be included in the sequence. The present paper describes the results of an experimental programme carried out in support of the certification of the Piaggio P.180 aircraft. The effects on crack propagation of truncating high loads and of omitting small cycles are discussed and compared with similar results in the literature. The test results are compared with analytical predictions, obtained by using a simple closure model. Finally, a number of observations about tensile mode/shear mode transition are made.
Effects of spectrum variations on fatigue crack growth
LAZZERI, LUIGI;LANCIOTTI, AGOSTINO
1992-01-01
Abstract
The definition of the load spectrum of the full-scale fatigue test of a new aircraft is a very delicate problem: among others, two important aspects are those concerning the maximum load and the minimum load range to be included in the sequence. The present paper describes the results of an experimental programme carried out in support of the certification of the Piaggio P.180 aircraft. The effects on crack propagation of truncating high loads and of omitting small cycles are discussed and compared with similar results in the literature. The test results are compared with analytical predictions, obtained by using a simple closure model. Finally, a number of observations about tensile mode/shear mode transition are made.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
