Abstract

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.

Highlights

  • Inclusion-Matrix InterfaceThe turbine disk is the core hot-end component of an aero turbine engine

  • From the analysis described in Sections 3.1.1 and 3.1.2, it can be conc prediction errors of the interface crack initiation life of the specimens with surface inclusion and specimens with semielliptical surface inclusion are

  • By observing the stress cloud diagram and the time-displacement history curve of the contact node, as shown in Figure 14, it is evident that when the inclusion is located at the same position of the matrix, the maximum stress is always located at the tip of the interface crack

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Summary

Introduction

The turbine disk is the core hot-end component of an aero turbine engine. The temperature in front of the turbine of modern aero engines can be as high as 1800 K and can reach 20,000 revolutions per minute. It is necessary to establish a feasible prediction model for the fatigue life of powder superalloys containing inclusions. Grison et al [15] presented a probabilistic model of fatigue failure of powder superalloy, which relates to the growth rate of cracks initiated from inclusions, and they discussed the risk of fatigue failure from particles in different positions. This is the main fatigue crack initiation mode in powder superalloys containing inclusions. The crack initiation life and crack propagation life of the inclusion-matrix interface are only studied at the stage of experimental measurement and statistical estimation, and the problem of inclusionmatrix interface debonding still needs more research. A finite element model was built, and a fatigue life prediction model based on damage mechanics was developed to calculate the interface crack initiation life. The effect of the location and shape size of the inclusion on the interface debonding was discussed

Construction of Fatigue Life Prediction Model
Damage parameter fitting when
Finite Element Analysis of Interface Debonding and Crack Initiation
Specimen with Elliptical Subsurface Inclusion
Stress
Specimen with Semielliptical Surface Inclusion
Damage
Evolution of Interface Stress Fields
11. Interface
Effect of Inclusion Characteristics on Interface Debonding
Effect of inclusion
Effect of Inclusion Shape Size on Crack Initiation
Findings
Conclusions
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