Fatigue crack growth from simulated flight cycles involving superimposed vibrations

Hawkyard, M.; Powell, B. E.; Stephenson, J.M; McElhone, M.

doi:10.1016/s0142-1123(99)00056-0

Cited by 15 publications

(5 citation statements)

References 6 publications

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“…Because of applying the non-linear temporal equation of motion, the transient vibration motions can be determined easily and the increments of crack growth associated with the vibration behaviors can be calculated synchronously. These related studies of coupling fatigue propagation and vibration have been presented by Dentsoras and Kourvaritakis [36], Hawkyard et al [37] and Shih and Wu [38]. …”

Section: Discussionmentioning

confidence: 84%

Dynamic instability of rectangular plate with an edge crack

Shih

2005

Computers & Structures

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Section: Discussionmentioning

confidence: 84%

Dynamic instability of rectangular plate with an edge crack

Shih

2005

Computers & Structures

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“…In our previous work, 21,23 crack monitoring during testing was carried out using a DCPD system with a milli‐voltmeter to monitor the changes in the voltage as the crack extends. In the current study, a DCPD system with a nano‐voltmeter has been used.…”

Section: Experimental Studiesmentioning

confidence: 99%

“…A modification of this approach by El Haddad et al 20 has been employed 5,16 to redefine the failure envelopes such that small crack behaviour can be accommodated. Such an approach, however, is insufficient when a flight cycle is concerned, where the threshold for a combined HCF and low cycle fatigue (LCF) is lower, 21 as the flight cycle serves as an underload to the HCF cycles at high R ratio, such that the threshold condition determined by standard tests for HCF cannot be applied to combined loading cases. In such components, the LCF, or major cycle loading, arises from the large cyclic variation of the conjoint centrifugal and thermal stresses, normally occurring once per flight, while the HCF or minor cycle loading arises from small‐amplitude vibrations.…”

Section: Introductionmentioning

confidence: 99%

Influence of foreign object damage on fatigue crack growth of gas turbine aerofoils under complex loading conditions

Hall

Byrne

Zhao

et al. 2008

Fatigue Fract Eng Mat Struct

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A B S T R A C T Foreign object damage (FOD) has been identified as one of the main life limiting factors for aeroengine blades, with the leading edge of aerofoils particularly susceptible. In this work, a generic edge 'aerofoil' geometry was utilized in a study of early fatigue crack growth behaviour due to FOD under low cycle fatigue (LCF), high cycle fatigue (HCF) and combined LCF and HCF loading conditions. Residual stresses due to FOD were analyzed using the finite element method. The longitudinal residual stress component along the crack path was introduced as a nodal temperature distribution, and used in the correction of the stress intensity factor range. The crack growth was monitored using a nanodirect current potential drop (DCPD) system and crack growth rates were correlated with the corrected stress intensity factor considering the residual stresses. The results were discussed with regard to the role of residual stresses in the characterization of fatigue crack growth. Small crack growth behaviour in FODed specimens was revealed only after the residual stresses were taken into account in the calculation of the stress intensity factor, a feature common to LCF, HCF and combined LCF + HCF loading conditions.

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“…This problem is very often encountered in the design of airplane engines disk or blades. HCF is known to contribute to fatigue crack growth if superimposed to a static load, as it is the case in HCF+LCF (Hall and Powell, 1997;Hawkyard et al, 1999;Byrne et al, 2003). With the present model as long as the amplitude of the HCF is inside the elastic domain of the cyclic plastic zone, no effect of the HCF can be found.…”

Section: Methodsmentioning

confidence: 85%

Time-derivative equations for fatigue crack growth in metals

Pommier¹,

Risbet²

2005

Int J Fract

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Predicting fatigue crack growth in metals remains a difficult task because available models are based on cycle-derivative equations, such as the Paris law, while service loads are often far from being cyclic. The main objective of this paper is therefore to propose a set of time-derivative equations for fatigue crack growth. The model is based on the thermodynamics of dissipative processes. For this purpose, three global state variables are introduced in order to characterize the state of the crack: the crack length a, the plastic blunting at crack tip ρ and the intensity of crack opening C. Thermodynamics counterparts are introduced for each variable. Special attention is paid to the elastic energy stored inside the crack tip plastic zone, because, in practice, residual stresses at crack tip are known to considerably influence fatigue crack growth. The stored energy is included in the energy balance equation, and this leads to the appearance of a kinematics hardening term in the yield criterion for the cracked structure. No dissipation is associated with crack opening, but to crack growth and to crack tip blunting. Finally, the model consists in two laws: a crack propagation law, which is a relationship between dρ/dt and da/dt and which observes the inequality stemmed from the second principle, and an elastic-plastic constitutive behaviour for the cracked structure, which provides dρ/dt versus applied-load. The model was implemented and tested. It reproduces successfully the main features of fatigue crack growth as reported in the literature, such as the Paris law, the stress-ratio effect and the overload retardation effect.

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Fatigue crack growth from simulated flight cycles involving superimposed vibrations

Cited by 15 publications

References 6 publications

Dynamic instability of rectangular plate with an edge crack

Dynamic instability of rectangular plate with an edge crack

Influence of foreign object damage on fatigue crack growth of gas turbine aerofoils under complex loading conditions

Time-derivative equations for fatigue crack growth in metals

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