ESDU data item simulates fatigue of helicopter rotor systems

Citation

(1998), "ESDU data item simulates fatigue of helicopter rotor systems", Aircraft Engineering and Aerospace Technology, Vol. 70 No. 5. https://doi.org/10.1108/aeat.1998.12770eab.067

ESDU data item simulates fatigue of helicopter rotor systems

ESDU data item simulates fatigue of helicopter rotor systems

Keywords Aircraft, ESDU, Fatigue, Helicopters, Rotor

ESDU International has released a new data item (97018) that describes the standard loading sequence for use in the fatigue assessment of helicopter rotor systems.

Helix and Felix are standard loading sequences for the hinged or fixed (semi-rigid) main rotors of helicopters.

The data are based on measurements of loads taken at the position of maximum flapwise bending moment on the rotor. In the case of articulated rotors, this position has been found to be on the lower surface of the blade at approximately half-rotor radius. On semi-rigid rotor systems it is located on the lower surface of the blade root.

Aerospace engineers use standard loading sequences, such as Helix and Felix, to simulate the magnitude and frequency of applied service loadings to particular components or structures.

The sequences are used primarily to compare the fatigue performance of different materials or components under various conditions. They are also used to evaluate fatigue data for preliminary design, for evaluation of fatigue lift prediction models, for assessing the degree of scatter in fatigue life data and for other related evaluation and comparison exercises.

The new data item (97018) also includes the TWIST & Mini-TWIST standard loading sequence for transport aircraft and FALSTAFF for tactical fighter aircraft.

ESDU International has also released a new data item (97018) that describes the standard loading sequence for use in the fatigue assessment of tactical fighter aircraft.

Known as FALSTAFF (fighter aircraft loading standard for fatigue), the sequence was developed to represent the stresses found in the lower wing surface near the fuselage joint in tactical fighter aircraft.

The data are based on load factor and strain measurements taken from a range of five tactical fighter aircraft, gathered from a variety of flight profiles. The integral ENvironmental FALSTAFF (FENSTAFF) sequence represents the stresses and environmental conditions expected to be experienced by tactical fighter aircraft constructed from composite materials.

Aerospace engineers use standard loading sequences, such as FALSTAFF, to simulate the magnitude and frequency of applied service loadings to particular components or structures.

The sequences are used primarily to compare the fatigue performance of different materials or components under various conditions. They are also used to evaluate fatigue data for preliminary design, for evaluation of fatigue life prediction models, for assessing the degree of scatter in fatigue life data and for other related evaluation and comparison exercises.

The new data item (97018) also includes the TWIST and MiniTWIST standard loading sequences for transport aircraft and Helix and Felix for helicopters.

ESDU International produces and updates comprehensive validated engineering data and related engineering procedures covering the aerospace, mechanical, chemical and structural engineering sectors. They are used by engineers in many of the world's largest industrial engineering groups to help optimise their product designs and represent a unique and invaluable engineering resource.

For further details contact Phillipa Fernandez, ESDU International. Tel: +44 (0) 171 490 5151.